Knee

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what is the management of LCL test

Initial treatment consists of medications and ice to relive pain and reduce the swelling of the knee. Your physician may recommend a knee brace with a hinge to help regain knee motion while protecting the LCL. Range of motion, stretching, and strengthening exercises are recommended. Rehabilitation of the LCL usually concentrates on reducing knee swelling, regaining knee range of motion, regaining muscle control and strength, and a short period of bracing. Surgery may be recommended depending on severity.

what are the signs and symptoms of meniscus tear

Pain, especially with standing on the affected leg and squatting, and tenderness along the joint of the knee Swelling of the affected knee, usually starting 1 to 2 days after the injury Locking or catching of the knee joint, causing an inability to straighten the knee completely Giving way or buckling of the knee

What are the special test/images for meniscus tear

Special testing: Apleys compression/distraction, McMurray's, Thessaly test Imaging: MRI

Meniscus injury o Pathology and MOI

The meniscus is usually injured because of a direct blow to the knee, twisting, pivoting, or cutting, as well as kneeling or squatting. It can also be damaged without any injury, due to aging

What are the signs and symptoms of LCL

Pain and tenderness on the outer side of the knee A pop, tearing, or pulling sensation at the time of injury Bruising (after 24 hours) at the site of injury Knee stiffness Limping, often walking with the knee bent

What are the signs and symptoms of HO

Restricted knee ROM Pain with palpation to the quadriceps muscle

Why are not more medial collateral ligament injuries associated with non-contact ACL injuries?

As Yu and Garrett18 pointed out in their review, clinical observation and epidemiology studies suggest that concomitant ACL/medial collateral ligament (MCL) injuries are relatively rare and occur in less than 30% of total ACL injuries.1 51 52 Therefore, the valgus motion and torque at the knee joint that are associated with increased ACL injury risk may present a conundrum to clinicians and researchers. The predominance of isolated ACL injury during non-contact mechanisms is a challenge for clinicians to explain. If non-contact ACL injuries occur as a result of valgus collapse of the knee joint, higher combined ACL/MCL injury patterns would be expected, particularly in women. The ACL and MCL both provide restraint to external valgus. Cadaveric studies show that the ACL appears to restrain knee valgus by limiting axial tibial rotation, whereas the MCL restrains knee valgus by limiting medial joint space opening.53 At low flexion angles, ACL deficiency produces greater increases in knee valgus rotation than isolated MCL deficiency. However, medial joint space opening in ACL-deficient knees is relatively small compared with the medial joint space opening in MCL- deficient knees.53 Therefore, both the ACL and MCL are important restraints to valgus loads and either one may potentially be injured during high knee valgus loading. Depending upon the age of the specimen, rate and orientation of loading, ACL failure loads are reported to range from approximately 640 to 2100 Newtons (N).54-56 In contrast, cadaveric MCL failure loads have been reported to be as high as 2300 N for complete MCL disruption.57 These disparities in relative failure loads may help to explain why the ACL may fail earlier than the MCL during external valgus loading. In addition, the reported cadaveric failure loads were determined by applying pure distraction to each ligament individually, with loads applied along the fibre lines. During pure valgus loading, the MCL takes stress along its fibre lines, whereas the ACL may be loaded in a suboptimal orientation to handle high stresses. Mommersteeg et al58 found that orientation of loading at the knee is more critical in the cruciate ligaments compared with the collaterals and that loading orientation may affect the tensile stiffness of the ACL. Mommersteeg and colleagues59 also showed that collagen density is different between human ACL and MCL, with the ACL showing significantly lower collagen density compared with the MCL. Variations in collagen density have been shown to correspond to differences in Young's modulus for the ACL and MCL.60 Therefore, even if the MCL is the primary restraint to an external valgus load, suboptimal orientation loading and collagen property differences may place the ACL at risk of failure before the MCL. Few studies have examined ACL and MCL loading concur- rently during a valgus load, and cross-referencing of studies to determine how the ACL and MCL behave simultaneously is complex due to the variability in laxity between specimens and different testing conditions. Yasuda et al61 demonstrated that during a valgus impact load, the ACL and MCL never elongated simultaneously during impact, and the time to peak elongation in the MCL occurred before the ACL at full extension. In contrast, at 30u of knee flexion, the ACL reached maximum elongation approximately 16 ms earlier than the MCL. As ACL injury probably occurs near initial foot contact (within the first 50 ms after contact) with the ground,9 a longer time to peak elongation could potentially explain how the ACL becomes at risk before the MCL during a valgus load. Shin et al62 conducted a modelling study that found that the MCL may only resist valgus loading effectively after some degree of medial joint opening. Valgus collapse that incorporates transverse plane rotations or that is combined with anterior tibial translations before the medial joint opens enough to strain the MCL may thus also potentially explain how the ACL could tear without MCL injury.22 48 Despite the epidemiological evidence that combined ACL/ MCL injuries are relatively less common than isolated inju- ries,1 51 52 combined ACL/MCL injuries may be underreported or underdiagnosed. A valgus load sufficient to rupture the ACL may not result in observable injury to the MCL. Cellular damage may occur, but not at a level that may be indicated by clinical examination, imaging or arthroscopy. In direct contrast to most imaging studies examining the incidence of ACL/MCL injury, Viskontas et al40 reported that 70% of ACL tears had associated grade 1-3 MCL injuries. The discrepancy between previous reports and the study by Viskontas et al40 may be due to the differences in the methods used to determine MCL injury. Many of the previous studies reporting ACL/MCL injuries did not include grade 1 injuries of the MCL or did not report injury grading schemes. Moreover, many studies relied exclusively on a clinical examination (valgus stress test) to determine injury to the MCL. Grood et al14 examined the ability of a valgus stress test to determine the ''grade'' of MCL injury and found that knees with complete MCL disruption only registered a motion increase of 5.5 mm; which by most clinical grading systems is a borderline grade 2 ligament injury (5- 10 mm). The clinical perception of a relatively low incidence of combined ACL/MCL injuries may be more related to the challenges of diagnosing minor sprains of the MCL compared with the more traumatic disruption of the ACL.63 The diagnostic sensitivity of an MRI for determining MCL injury is less than 60%, compared with the relatively high sensitivity (86%) and specificity (92%) for diagnosing an ACL injury.64 Whereas complete traumatic midsubstance ruptures of the ACL are common, complete MCL midsubstance disruptions are rare. The majority of diagnosed MCL injuries are partial ligament tears in which the MCL often splinters at the deep femoral or tibial insertions rather than sustaining midsubstance disruption. Moreover, the complex anatomy of the medial and poster- omedial structures of the knee joint makes it difficult to determine isolated MCL injury. Previous studies that examined MCL injury have often differed in their description of MCL injury, with regard to the inclusion of superficial MCL, deep MCL structures and/or the posterior oblique ligament, as a result of the difficulty in differentiating between the structures during physical and imaging examinations.65 Also, clinicians may not be highly motivated to diagnose an MCL injury, especially a relatively minor sprain, with an ACL rupture because it does not significantly alter the course of treatment. The low reported incidence of combined ACL/MCL injury thus does not necessarily indicate that ACL injuries do not occur as a result of knee valgus collapse. Cumulatively, and in direct contrast with the assertions of the review by Yu and Garrett,18 this evidence indicates that valgus collapse can potentially lead to non-contact ACL injury. As described above, the knee probably experiences high loading conditions simultaneously in multiple planes, particularly in sporting manoeuvres such as landing, jumping and cutting, all of which require movements in multiple planes. It is thus unlikely that a non-contact ACL injury occurs in a single isolated plane, especially in the female athlete.

What additional evidence is there that valgus collapse is an important contributor to ACL injury?

Consider how clinical tests of knee stability parallel the forces that potentially occur at the knee during an inciting event. The Lachman's and anterior drawer tests indicate the importance of the ACL in restraining anterior tibial translation. Similarly, the pivot shift test (fig 3) is the most specific clinical test for ACL deficiency; it has 98% specificity (95% CI 96 to 99).35 When comparing the relative importance of these motions, note that ACL-deficient patients can generally function well when they limit themselves to sagittal plane movements; however, rotational movements often lead to feelings of instability and symptomatic ''giving way'' episodes. The pivot shift test stresses the rotational restraint of the ACL and a large pivot shift predicts a poor outcome following injury.36 We postulate that the pivot shift probably reproduces the luxations that occur during an ACL injury. Clinical imaging and diagnostic studies also indicate that valgus collapse probably occurs during ACL injury. Bone bruises of the lateral femoral condyle or posterolateral portions of the tibial plateau occur approximately 80% of the time in magnetic resonance imaging (MRI) studies after acute ACL injury (fig 4).37-40 Lateral tibial and femoral bone bruises associated with acute ACL injuries indicate that compression occurs laterally while the medial aspect of the joint unloads. Posterior tibial plateau bone bruises could result from internal tibial rotation, femoral external rotation, abduction and/or anterior tibial translation. Adding to the argument that there may be sex-specific mechanisms of injury, Fayad et al41 reported that women more commonly acquired posterolateral tibial bone bruises after ACL injury, whereas men had more medial meniscus, lateral collateral ligament and posterior cruciate ligament injuries. This sex difference in concomitant injuries associated with ACL ruptures is consistent with women having more valgus-driven injury mechanisms and men experiencing more sagittal plane- oriented ACL injury mechanisms. As women demonstrate greater knee valgus postures and moments compared with men during jumping, landing and cutting activities, their risk of dangerous knee valgus mechanics is elevated.42 43 An underrecognised, but unmodifiable factor that may increase the risk of ACL injury as a result of valgus collapse is the slope of the posterior tibial plateau. ACL-injured patients may have greater posterior lateral tibial plateau slopes compared with controls (but not medial tibial slopes). This may predispose them to more transverse plane rotation during high-risk manoeuvres.44 Both Kujala et al45 and Brandon et al46 found that greater posterior tibial slopes were associated with higher pivot shift grades and an increased likelihood of experiencing symptomatic giving way episodes in ACL-deficient patients. Therefore, a large posterior tibial plateau slope combined with greater lateral femoral condylar translation on the tibia compared with the medial condyle increases the likelihood of transverse plane rotations and probably increases an individual's risk of ACL injury as a result of valgus collapse.47 Several cadaveric studies demonstrate that the ACL experi- ences increased force during valgus loads.22 48 Quadriceps force coupled with a valgus load increases the ACL force up to 100% compared with valgus loads without a quadriceps force.22 Similarly, coupled valgus loading with anterior tibial force leads to higher ACL forces and strains than isolated anterior tibial force.48 Withrow et al49 demonstrated that valgus knee align- ment led to 30% greater ACL strains compared with knees in neutral alignment when subjected to impulsive compression loads.

SAGITTAL PLANE MECHANISM: UNLIKELY TO BE THE SOLE PLANAR ACL INJURY MECHANISM IN WOMEN

During sagittal plane movements at the knee joint, anterior shear force at the proximal end of the tibia through the patella tendon can be produced by quadriceps muscle contractions.24 66 Anterior shear of the proximal tibia relative to the femur directly loads the ACL, and sagittal plane knee angles near full extension (0-30u of flexion) increase this anterior tibial shear force.22 24 66 67 Theoretically, a powerful quadriceps force near full knee extension could thus produce enough anterior shear force at the tibia to cause ACL rupture.22 68 Cadaveric, diagnostic and in-vivo arthroscopy studies demon- strate that the ACL is a primary restraint to anterior shear loading14 16 22 and ACL-deficient knees have significantly more anterior tibial translation compared with ACL intact condi- tions.69 70 These findings indicate that a function of the ACL is to prevent sagittal plane translations, and large anterior tibial shear forces could potentially compromise the ACL. However, it is important to consider that most of these studies solely evaluated anterior tibial translation and did not consider other planes in the diagnostic evaluation. Publication biases towards the sagittal plane restraints of the ACL have driven many of the oversimplified assumptions of sagittal plane proponents to ACL injury. The bone bruise data strongly contradict a solely sagittal plane mechanism of ACL rupture, most especially in women. As described above, bone bruises of the lateral femoral condyle or posterolateral portions of the tibial plateau are common after acute ACL injury, and these bone bruising patterns may indicate that the tibia shifts anteriorly relative to the femur during ACL injury.37-40 The slope of the tibial plateau may also contribute to sagittal plane ACL injury mechanisms, as pure compression across a tibial access with 5-15u of posterior slope could increase anterior tibial translation and ACL strain.46 Brandon et al46 found an association between increased posterior tibial slope and ACL injury. However, if the injury mechanism was solely as a result of anterior tibial shear, the bone bruise patterns on MRI after ACL injury would most likely be located along the medial tibial plateau as well as the lateral tibial plateau. As the bone bruises are most often located laterally, in addition to the posterior tibial pattern, lateral compression and valgus probably occur during these ACL injuries. The relationship between the knee flexion angle and the potential for ACL injury has also been explored extensively in the literature. Interview and video studies indicate that ACL injury usually occurs at shallow (0-30u) knee flexion angles.9- 12 21 71 72 Cadaveric studies show that the knee joint has the potential to translate more in the sagittal plane during shallow knee flexion angles, and anterior tibial shear forces generate the greatest ACL loads during 20-40u of knee flexion.22 69 73 At the same time, women have been suggested to have shallow knee flexion angles during landing, jumping and cutting tasks compared with men.31 74 75 However, other studies show no sex difference or even greater knee flexion in women during athletic tasks.30 76 77 Furthermore, the knee flexion angle at landing does not appear to predict ACL injury risk,20 and videos of ACL injuries indicate that women may have similar or even greater knee flexion angles than men during the injury event.9 10 Many sports manoeuvres induce large quadriceps forces at relatively shallow knee flexion angles, which may increase anterior tibial shear and ACL strain.24 78-83 Isolated quadriceps contractions increase ACL strain and force during shallow knee flexion angles,79 81-83 and electromyographic studies show that women have significant neuromuscular imbalances between quadriceps and hamstrings recruitment, which create difficulty for deceleration from a landing and control of anterior tibial translation.84 85 Withrow et al86 showed that ACL strain is proportional to increased quadriceps forces during high impact loads. Strong quadriceps contraction can produce anterior tibial translation great enough to injure the ACL during shallow knee flexion angles.24 87 When a 4500 N quadriceps force was applied to cadaveric specimens, six of the 11 specimens sustained a partial or complete ACL rupture.24 However, quadriceps contraction appeared to affect ACL loading in more than one plane of motion, with knee internal rotation and valgus moments occurring coincident with anterior tibial translation.24 Cadaveric and mathematical modelling studies indicate that hamstrings co-contraction with quadriceps contraction can lead to joint compression, decrease anterior tibial translation and effectively reduce excessive forces in the ACL, particularly between 15u and 60u of knee flexion.66 88 89 Shin et al90 reported that large ground reaction forces directed posterior relative to the proximal tibia help protect the ACL during landing from a jump and during a run-to-stop simula- tion. Moreover, several mathematical models have demon- strated that sagittal plane mechanisms alone cannot account for ACL forces high enough to rupture the ACL.33 91 McLean and colleagues32-34 used forward dynamic musculoskeletal models to simulate random perturbations during cutting movements and found that peak anterior drawer forces never led to ACL forces high enough to cause ACL injury. Therefore, despite the evidence that sagittal plane mechanics can cause large ACL loads, it is highly unlikely that non-contact ACL injuries result exclusively from a sagittal plane mechanism (especially in the female athlete).

Treatment Methods and Pain

In the randomized controlled trial by Clark et al,18 81 sub- jects with anterior knee pain were randomly assigned to 4 groups: (1) exercise, taping, and education, (2) exercise and education, (3) taping and education, and (4) education alone. Each group received the designated intervention for 3 months. At 3 and 12 months after treatment began, each subject was assessed for patient satisfaction, indicated as the discharge rate, visual analog scale (VAS) rating for pain, Western On- tario and McMaster University lower limb function scores, the Hospital Anxiety and Depression Scale, and quadriceps strength. Measurements of the subjects' quadriceps strength will be discussed in the ''Neuromuscular Control'' section. Using a categorical variable analysis, patients who exercised (groups 1 and 2) were significantly more likely to be dis- charged at the 3-month assessment than the nonexercise pa- tients (P .001). Taping alone did not improve the discharge rate over patients in the nontaped groups. No significant dif- ferences were noted in improvement of VAS for pain, Western Ontario and McMaster University lower limb function scores, or Hospital Anxiety and Depression scores among any of the groups at the 3-month or 12-month assessments. However, the patients engaged in exercise programs were significantly more likely to be satisfied and have less pain after a year (P .001). Limitations of this study include a low percentage of patient return after a year of treatment and the authors' failure to indicate whether those patients who were discharged at 3 months continued any form of exercise between the 3- and 12- month assessments. The PEDro scale rating for this study was 7/10. Allocation was not concealed, and the therapists and as- sessors were not blinded. Harrison et al21 investigated the efficacy of different phys- ical interventions on 113 patients randomly allocated to a group with a home strengthening and flexibility exercise pro- gram (group 1), a group with a similar exercise program but carried out in a clinical setting and monitored by a physical therapist 3 times a week for 1 month (group 2), or a group with a physiotherapist-directed program including exercise similar to the other 2 groups, McConnell patellar taping, and biofeedback 3 times a week for 1 month (group 3). At the 1- month reassessment, group 3 demonstrated significant im- provement on various pain scales and questionnaires (visual analog scale for pain, Functional Index Questionnaire, clinical change score, and Patellofemoral Function Score) and knee pain threshold (time to pain experience) during a step test compared with group 2 (P .05) but showed no significant improvement over group 1. The authors concluded that bio- feedback and patellar taping both had a significant improve- ment on pain, but in a long-term follow-up, any treatment program could improve the patients' pain and function. For short-term reduction of pain, it appeared that the addition of taping and biofeedback was beneficial; however, because of the confounding variable of biofeedback in group 3, it is dif- ficult to conclude that patellar taping as an individual rehabil- itation component was superior to the exercise interventions reducing pain. This study yielded a PEDro score of 5/10. No points were awarded for concealed allocation, blinding of the therapists and subjects, obtaining more than 85% of fol- low-up measurements, or intention-to-treat analysis. In the randomized study by Kowall et al,25 25 subjects with PFPS were randomly allocated to 2 groups: patellar taping and control (no patellar taping). Both groups were instructed to pursue physical therapy and home exercise programs. Their VAS scores for pain as well as isokinetic strength and EMG activity of the quadriceps were assessed. (Isokinetic strength and EMG activity will be discussed in the ''Neuromuscular Control'' section.) Both groups had significantly less pain (P .05) with activities of daily living after physical therapy. However, improvement of pain, isokinetic quadriceps strength, and quadriceps EMG activity between the groups did not dif- fer, indicating that adding patellar taping to a standard physical therapy program did not affect these measures. The PEDro scale rating for this study was 3/10. This study lacked con- cealed allocation; information about baseline characteristics; blinding of the subjects, therapists, and assessors; intention-to- treat analysis; and information on point measures and mea- sures of variability.

IT Band Friction

Irritation of IT band with repetitive flexion when taught against lateral femoral condyle

CLINICAL OUTCOME STUDIES Meniscus Repair

Results of suture repair of meniscus tears have predictable success rates in terms of resolution of symptoms for tears located in the peripheral re- gion.9,12,19,21,55,57,68 Only a few authors have pub- lished findings of meniscal repair using arrows and the success rates vary and appear to deteriorate with longer follow-up.2,29,43,48,50 In addition, subcutaneous migration of meniscal arrows has been documented by many authors in which further surgery is required to remove the device.10,13,27,33,67 Another less- frequently reported complication associated with meniscal fixators is chondral injury due to either migration of the device or its failure to absorb completely.3,16,30,78 Too few data exist in the literature to assess the efficacy of arrows or other meniscal fixators for tears that extend into the central one- third zone.29,84 Less predictable results have been reported follow- ing suture repair of meniscus tears that extend into the central one-third region.6,12,68,80,86 Differences in outcome have occurred due to variations in suture technique and placement along the tear site, postop- erative rehabilitation, and concurrent procedures such as ACL reconstruction. We have described the results of these complex repairs in 4 separate investi- gations, the largest of which involved 198 meniscal repairs in 177 patients.80 There were 138 male and 39 females whose average age at the time of the repair was 28 years (range, 9-53 years). An ACL reconstruc- tion was done either with or shortly after the menis- cus repair in 126 patients (71%). The meniscal repairs were evaluated by clinical examination a mean of 42 months (range, 23-116 months) postoperatively, follow-up arthroscopy (91 repairs) a mean of 18 months (range, 2 to 81 months) postoperatively, or both. The rate of reoperations for meniscal symptoms was 20%. This study's reoperation rate should not be interpreted to be the rate of meniscal failure, but rather the incidence of tibiofemoral joint symptoms in this group of patients. All patients who had tibiofemoral symptoms underwent repeat arthroscopy. There were no complications or limitations of knee motion. The results of this investigation led us to recommend repair of meniscal tears that extend into the central one-third region, especially in patients in their 20s and 30s and highly competitive athletes. Even though the rate of residual tibiofemoral symp- toms was higher than that previously reported for repair of peripheral meniscal tears,12 we believe the benefits of a potentially functional meniscus outweigh the risks of reoperation. We investigated the results of repair of meniscal tears in the central one-third region in middle-aged patients to determine the efficacy of this operation in individuals 40 years of age and older.59 Thirty repairs in 29 patients were evaluated by clinical examination a mean of 34 months (range, 23-71 months) postop- eratively, follow-up arthroscopy (6 repairs) a mean of 24 months (range, 16-36 months) postoperatively, or both. There were 23 men and 6 women whose average age at the time of repair was 45 years (range, 40-58 years). Concurrent ACL reconstructions were performed in 21 patients (72%). At follow-up, 26 meniscal repairs (87%) were asymptomatic for tibiofemoral joint symptoms. The concomitant ACL reconstructions appeared to influence the rate of asymptomatic meniscal repairs, as 91% of these knees were free of symptoms at follow-up, compared to 75% of those who did not require ACL reconstruction. Other authors have demonstrated that an ACL recon- struction done with meniscal repair may protect the repair site through increased anterior-posterior stabil- ity and enhance healing from the postoperative hemarthrosis.15,19,41,57 There were no complications or limitations of knee motion in our series. This study lead us to conclude that the preservation of meniscal tissue should be attempted whenever possible, regard- less of age, in athletically active patients. In another study, we determined the outcome of repair of meniscal tears in the central one-third region in patients under the age of 20 years.58 This represented the first investigation to examine these types of repairs exclusively in this age range. Seventy- one repairs in 64 knees were evaluated by clinical examination a mean of 51 months (range, 24-196 months) postoperatively, follow-up arthroscopy (36 repairs) a mean of 18 months (range, 3-60 months) postoperatively, or both. Concomitant ACL recon- structions were done in 47 knees (73%). At follow-up, 53 repairs (75%) were asymptomatic for tibiofemoral joint symptoms and had not required follow-up arthroscopy. Two knees that had an associated ACL reconstruction required a gentle manipulation early postoperatively for a limitation in knee flexion; both regained full ROM.

Posterolateral Rotatory Instability (PLRI)

The PLC provides restraint to various types of pathologic knee motion: posterior tibial translation near full extension, external rotation of the tibia on the femur (where the PCL provides secondary restraint), and varus rotation all are affected by the structures of the PLC. The PLC is composed of both static and dynamic components. The static struc- tures are the LCL, the arcuate ligament complex (deficien- cies of which are particularly implicated in PLRI),51,71 the fabellofibular ligament, and the posterolateral capsule. The dynamic structures consist of the ITB, the biceps tendon, and the popliteus muscle-tendon complex, which includes the popliteofibular ligament and its fascicles.44 Performing a reliable clinical examination of the PLC is an important but often underdeveloped skill. Failure to diagnose and treat PLC injury may be a major cause of failure of ACL reconstructive surgery.94 Without a thor- ough and competent examination, PLRI may be entirely overlooked as a cause of posterolateral joint pain, or symp- toms may be mistakenly attributed to lateral meniscus tear. Chronic PLRI is also frequently misdiagnosed as a primary tibia vara deformity, with subsequent incorrect treatment by proximal tibial osteotomy. Posterolateral rotatory instability generally occurs as a consequence of a force directed posteriorly against the knee with resulting hyperextension, such as may occur during a block in American football.51 Symptoms include posterolateral pain, discomfort with standing, a perception of the knee hyperextending, and the sensation of the knee "giving out." Multiple studies have been performed to establish the relative importance of the posterolateral structures.39,41,81 Gollehon et al39 performed selective cutting studies in fresh cadaveric specimens to establish the roles of the PCL, LCL, and the deep ligament complex, consisting of the popliteus tendon, arcuate ligament, fabellofibular liga- ment, and posterolateral capsule. These structures were sectioned in different sequences to establish their impor- tance and contribution to static knee stability. Anteroposterior translation, internal and external rota- tion, as well as varus and valgus motions were evaluated after sectioning of the various structures. Isolated section- ing of the PLC resulted in an increase in posterior trans- lation (especially as the knee approached full extension), an increase in external tibial rotation, and an increase in varus instability (with the greatest increase in varus noted at 30°). Combined section of the PLC and the PCL resulted in further increases in external rotation and varus insta- bility at 90°. By understanding these aspects of knee anatomy and biomechanics, such alterations can be tested clinically using corresponding physical examination tests. Posterior translation may be assessed using tests described above. Tests for PLRI are mentioned in this paragraph and described below. Care must be taken to dif- ferentiate between PLC, PCL, and combined injuries because both the PLC and PCL may contribute to posterior tibial restraint depending on the degree of knee flexion. Negative posterior drawer testing results with the tibia in neutral and internal rotation can assist in ruling out PCL injury.51 Abnormal external tibial rotation can be evalu- ated with the dial test and the reverse pivot-shift test. Jakob et al55 have also used the reverse pivot-shift test to distinguish PLRI from ALRI. External rotation coupled with posterior translation is assessed with a posteriorly directed force using the posterolateral drawer test. Hughston and Norwood52 described confirmation of PLRI with the posterolateral drawer test and the external rota- tion recurvatum test. The posterolateral external rotation test may also detect posterolateral subluxation of the lat- eral tibial plateau: positive findings may also be consistent with an isolated PLC injury or combined injury to the PLC and the PCL, depending on the knee angle(s) at which sub- luxation occurs. These tests are clarified below. Finally, pathologic varus motion may be detected using the varus stress test at 0° and 30°, which is described below.

Suprapatellar plica syndrome. Tx

The plica will get stressed over the medial femoral condyle with knee flexion, so avoid activities with repetitive flexion, such as bike riding and running.

Patellar tendinopathy Pathology and pathophysiology

The predominant pathological feature of patellar tendinopathy is tendinosis, typically in the deep posterior portion of the patellar tendon adjacent to the lower pole of the patella [13]. Tendinosis is characterized by progressive tissue degen- eration with a failed reparative response and the complete absence of inflammatory cells [10,12,14]. Macroscopically, this makes the afflicted region of the tendon soft and gives it a yellow-brown, disorganized appearance—an appearance that is commonly labeled ''mucoid degeneration'' [15-18]. This contrasts with the normal appearance of a glistening, stringy, parallel-organized, white tendon. When viewed microscopically, the pathological region is distinct from normal tendon, with both matrix and cellular changes. Instead of clearly defined, parallel, and slightly wavy collagen bundles, tendinopathy is associated with relative expansion of the tendinous tissue, loss of the longitudinal alignment of collagen fibers, and loss of the clear demarcation between adjacent collagen bundles [4,10, 12-14,19]. The tissue has lost its normal reflective appearance under polarized light, and there is gradual and increasing separation of collagen fibers that distorts the normally dense homogenous polarization pattern [4,10]. Occasional clefts in the collagen suggest microtears that may be interpreted as microscopic partial ruptures [20]. In addition, there are frequently focal regions of intratendinous calcification [10,21-24]. The latter may arise due to traction injury to the inferior pole of the patella [10,24]; however, recent evidence has shown the calcification to have formed discretely via endochondral ossification [21]. Multiple cellular changes coexist with the matrix changes in tendinopathy. The most obvious of these changes is hypercellularity resulting from an increase in cellular proliferation [25]. There is atypical fibroblast and endothelial cellular proliferation [12,19,26], and extensive neovascularization [10,14,19,22,27]. These changes represent an attempt at healing. The collagen-producing tenocytes lose their fine spindle shape, and their nuclei appear more rounded and sometimes chondroid in appearance, indicating fibrocartilaginous metaplasia [13]. Of note is the consistent finding of a clear absence of inflammatory cells [4,10,12,14]. Despite the absence of inflammatory cells in patellar tendinopathy, mediators in the inflammatory cascade appear to be involved in its pathophysiology. Of particular note is the involvement of cyclooxygenase-2 (COX-2). COX-2 is an inducible enzyme that rate-limits the production of proinflammatory prostaglan- dins, such as PGE2. In tendons harvested from patients with patellar tendinopathy, both the tendon tissue itself and harvested cells expressed higher levels of COX-2 than healthy control patellar tendons [12]. In addition, the harvested cells produced greater in-vitro quantities of PGE2 [12], although this has yet to be confirmed in The potential involvement of inflammatory pathways in patellar tendinopathy has implications with regard to the use of anti-inflammatory agents in its management (discussed later).

Medial Meniscus Transplantation

There are 2 techniques for medial meniscus trans- plantation: the central bone bridge technique, which is preferred, and a 2-tunnel technique that consists of separate anterior and posterior bone attachments and tunnels.64 The decision-making criteria for the appro- priate technique is made following exposure and direct measurement of the anterior-posterior and medial-lateral dimensions required for the transplant. The central bone bridge technique is used if the surgeon determines that the transplant will fit in the proper position just adjacent to the ACL tibial attachment, without excessive medial tibial overhang, and that the anterior and posterior attachment loca- tions will be anatomically correct. If the transplant requires adjustment to fit to the medial tibial plateau (by moving the anterior horn placement further laterally), then the 2-tunnel technique is selected. The central bone bridge technique is the same as described for lateral meniscus transplants. The tibial slot is prepared to the dimensions of 8 to 9 mm in width and 10 mm in depth. The central bone bridge of the transplant is sized to a width of 7 mm (or 1 mm less than the dimension at the tibial site) and a depth of 10 mm.24 A vertical suture is placed through the junction of the posterior and middle thirds of the transplant. The meniscus is passed through an arthrotomy into the knee, with tension applied on the sutures to facilitate proper positioning (Figure 7A). The bone bridge of the transplant is aligned with the recipient tibial slot and the knee is flexed, extended, and rotated to confirm proper alignment. An absorbable bone interference screw is inserted adjacent to the bone bridge (Figure 7B). The menis- cus transplant is sutured with vertical divergent sutures (2-0 Ethibond) under direct visualization. The anterior arthrotomy is closed and inside-out vertical divergent sutures are placed to suture the meniscus to the bed, remove any implant undulations, and restore circumferential meniscal tension. f it is determined that the central bone bridge technique cannot be performed, the surgeon must use the 2-tunnel technique. The medial meniscus transplant is fashioned to create a posterior bone plug 8 mm in diameter and 12 mm in length, and an anterior bone plug 12 mm in diameter and 12 mm in length. Two 2-0 nonabsorbable Ethibond sutures are passed retrograde through each bone plug. Two other sutures are placed in the meniscus adjacent to the bone attachment for subsequent secure fixation of the bone plugs within the tibial tunnel. A tibial tunnel is created at the anatomic posterior horn meniscus attachment, just medial and proximal to the posterior cruciate ligament (PCL) attachment. A 3-cm anteromedial arthrotomy is created, through which the posterior bone portion of the transplant will be passed. Secondary meniscus body sutures are passed out the posteromedial approach. The knee is flexed to 20° under a maximum valgus load to pass the posterior bone portions of the transplant; the secondary meniscus body suture is held by an assistant. Care is taken not to advance the posterior meniscus body into the tibial tunnel, but to just seat the bone portion of the graft in order not to shorten the meniscus transplant. The posterior me- niscus bone attachment and midbody sutures are tied over a tibial post to provide tension in the posterior bone attachment and posterior one third of the meniscus. The knee is flexed, extended, and rotated to assess whether the transplant is in the correct position in the joint. A 12-mm rectangular bone attachment is fashioned to correspond to the anterior bone portion of the meniscus transplant. A 4-mm bone tunnel is created at the base of this bone trough, which exits at the anterior tibia, and through which the anterior horn is seated. Full knee flexion, extension, and rotation are performed to determine proper transplant placement and fit. Starting in the posterior horn, an inside-out meniscus repair is performed using multiple vertical divergent sutures both superiorly and inferiorly. Con- stant tension is placed on the transplant (from posterior to anterior) to restore circumferential ten- sion (Figure 8).

Posterolateral External Rotation Test

This is a combination of the posterolateral drawer and dial tests, performed at both 30° and 90°. Recommended Technique. With the patient supine, cou- pled posterior and external rotation forces are applied to the tibia of the involved leg in flexion of 30° and then 90°. The amount of posterolateral subluxation by the lateral tibial plateau is noted. Subluxation that occurs only at 30° is consistent with an isolated PLC, whereas subluxation at both 30° and 90° is indicative of combined injury to the PLC and the PCL.

Range of Knee Motion and Flexibility

We instruct the patient to perform passive knee flexion and passive and active/active-assisted knee extension exercises beginning the first day postopera- tively. Active knee flexion is limited to avoid ham- string strain to the posteromedial joint. Initially, these exercises are performed in the seated position from 0° to 90°, with flexion advanced to 120° by the third to fourth week, and 135° by the fifth to sixth week (Table 3). ROM exercises are performed 3 to 4 times daily (10- to 15-minute sessions) until normal motion is achieved. Full extension is considered to be 0°. Caution is used to avoid hyperextension in individu- als who have had anterior-horn meniscus repairs. A knee with an extensive repair may be required to limit ROM to 0° to 90° for the first 2 weeks beforeprogressing the ROM program. If 90° is not easily achieved, the patient may be at risk for a flexion complication. Individuals who develop a limitation in either flexion or extension are placed into a specific treatment program early postoperatively, as previously described in detail.34,65 An overpressure program is usually successful in achieving the last few degrees of extension, if initiated within the first few weeks postoperative. The patient is instructed to prop the foot and ankle on a towel to elevate the hamstrings and gastrocnemius, which allows the knee to drop into full extension. A 4.5-kg (10-lb) weight may be added to the distal thigh and knee to provide overpressure to stretch the posterior capsule. This program is done 6 to 8 times per day, for 10 minutes at a time. Flexion exercises are done in the seated position, using the opposite lower extremity to pro- vide overpressure. Other options include chair roll- ing, wall sliding, passive quadriceps stretching, and ROM devices such as the ERMI Knee Flexionator (ERMI, Atlanta, GA). ROM exercises are accompanied by patellar mobili- zation (in the superior, inferior, medial, and lateral directions), which we believe is paramount to pro- mote full knee ROM (Figure 11). Flexibility exercises, beginning with the hamstring and gastrocsoleus mus- culatures, are also initiated the day following surgery and are done 3 times per day. Quadriceps and iliotibial band flexibility exercises are incorporated at 7 to 8 weeks postoperative. Sustained static stretching is performed, with the stretch held for 30 seconds and repeated 5 times. Our ROM program has been proven throughout many years to be effective, as no patient who has undergone an isolated meniscus repair or transplant has required further arthroscopic surgery or lysis of adhesions for a knee motion complication. In our studies, only 2 of 193 patients who underwent menis- cal repair, and 4 of 38 patients who had a transplant, required a gentle manipulation for a limitation of flexion. In these 6 patients, a major concomitant procedure, such as an ACL or PCL reconstruction, had been performed. The therapist should be aware of the increased potential of a knee motion problem in patients who undergo combined procedures, and that closer supervision and additional exercises may be required to successfully restore normal ROM. We have not experienced a difference between medial and lateral meniscus repairs or transplants in regard to knee motion complications.

The Pivot-Shift Test

While the phenomenon was recognized by numerous authors, the term "pivot shift" was first coined and described by Galway and MacIntosh.38 This term is used to both denote a specific sign that may be elicited during physical examination and to characterize a patient's subjective description of their knee "going out" during an attempt to laterally pivot.71,78,79 The pivot shift does not actually represent a knee instability event itself but rather a reduction from a state of anterior tibial sub- luxation.28 Slocum et al103 and Losee et al76 have described important variations of the pivot-shift test. In the original description of the pivot-shift maneuver, it was revealed that ACL sectioning alone caused the phenomenon in 89% of cadaveric knees tested. In contrast, sectioning of the ili- otibial band (ITB), biceps tendon, lateral collateral liga- ment (LCL), and popliteus was insufficient to produce a pivot shift.38 The pivot-shift test is particularly useful for confirming that anterior laxity is likely to be clinically si nificant65 and may thus represent a relative indication for ACL reconstructive surgery. To perform the pivot-shift maneuver successfully, the examiner must appreciate subtle motions of the knee. As stated succinctly by Cummings and Pedowitz, "The goal is to observe a sudden shift of the tibia relative to the femur as the knee goes from an extended to a slightly flexed position."18 Studies of the pivot-shift test have reported high sensitivities for detecting ACL injury ranging from 84% to 98.4%. The test's specificity has been shown to vary more widely, with reported values from as low as 35% in the alert patient to as high as 98.4% in the anesthetized patient.23,62,77 The pivot-shift phenomenon may be explained as follows. In the ACL-deficient knee, anterior subluxation occurs in knee extension. When the PCL and posterior capsule are relaxed by initiation of knee flexion, a valgus stress will cause persistent anterior subluxation of the lateral tibial plateau due to tibial contact with the lesser curvature of the lateral femoral condyle. As the posterolateral tibial plateau shifts anteriorly, it impinges against the lateral femoral condyle at its greater curvature. This impingement prevents further anterolateral tibial subluxation and causes a hinging effect at the site of impingement. Continued flexion levers open the anterior aspect of the knee, generating a critical tension in the ITB acting at the anterior lateral tibial tuber- cle (Gerdy tubercle). At 30° to 40° of knee flexion, the ITB changes in relation to the axis of the knee, specifically chang- ing from a knee extensor to a knee flexor. Tension in the ITB pulls the subluxated lateral tibial plateau posteriorly, the tibia no longer impinges on the femoral condyle, and the examiner perceives a sudden clunk as the joint reduces. This reduction phenomenon allows the examiner to appreciate a positive pivot-shift sign.76 Critical maneuvers in the pivot-shift test, in addition to internal tibial rotation and valgus stress mentioned above, may also include ranging the tibia through external rota- tion and positioning of the hip. Some authors have sug- gested that external rotation of the tibia can produce an equal or greater pivot-shift sign on physical examina- tion.1,11,56,89 However, evaluation of the pivot shift using the externally rotated tibia must be distinguished from demonstrations of posterolateral laxity. Gollehon et al39 showed that the posterolateral structures of the knee resist external tibial rotation but can be differentiated from the pivot shift in external rotation by 2 methods. First, the pivot shift will remain positive when tested in internal rotation, whereas the laxity secondary to postero- lateral damage will not. Second, careful palpation of the lateral tibial plateau in relation to the femoral condyle will allow the examiner to differentiate posterolateral versus anteromedial subluxation.39 (This is reiterated in the dis- cussion of rotational instability below.) final and often overlooked factor is hip position. It has been shown that both hip position and tibial rotation inde- pendently and collectively affect the grade of the pivot shift. According to Bach et al,1 a combination of hip abduc- tion and external tibial rotation produces statistically higher pivot-shift grades, whereas hip adduction combined with either internal or external tibial rotation lowers the grade. It has been shown that internal rotation of the tibia and adduction of the hip both tighten the ITB, causing ear- lier tibial reduction and a consequent decreased grade.20 The potential effect of hip and tibial positioning on locking and unlocking of the knee has been proposed as another explanation for these observations.72 In summary, whether by this mechanism or by the effect on the ITB or some com- bination thereof, abduction and slight flexion of the hip may be used to enhance the positive results of a pivot-shift test.1,56,89 It has been suggested that when performing the pivot-shift test, one should not rely on a "1 test, 1 position" evaluation of the pivot-shift phenomenon.72 The examiner should be aware of the possibility of false findings from a pivot-shift test.34,4 • Ligamentous laxity in the face of an intact ACL may allow a subluxation to occur that mimics a positive pivot-shift test result. Therefore, both knees must always be tested. • Rupture of the ITB prohibits the telltale reduction phe- nomenon. Losee74 reported that an insufficient ITB will permit continued subluxation through increased knee flexion (beyond 40°). • Medial instability can prevent the necessary valgus forces from being applied to elicit a positive pivot shift. • A locked bucket-handle tear of the meniscus may block a pivot-shift phenomenon from occurring. • The posterior horn of the lateral meniscus may act as a buttress against anterior subluxation of the antero- lateral tibial plateau. Thus, in the absence of an intact posterior horn lateral meniscus, there may be a blunting of the clinical test because the tibia can slip beneath the femur in a more subtle fashion, without the expected "sudden jump." Recommended Technique. In this test, the patient assumes a supine position and attempts to relax the leg muscles as much as possible. The examiner holds the affected leg in full extension and internal rotation while lift- ing the limb off of the table. The knee is flexed during appli- cation of concomitant valgus stress. In an ACL-deficient knee, the lateral tibial plateau will be anteriorly subluxated at the beginning of the test (knee flexion less than 30° plus valgus stress). As flexion increases to 30° to 40°, this antero- lateral tibial subluxation will abruptly reduce (positive test result). This is palpable and sometimes audible. The grading system for the pivot-shift test is based on the relocation event, specifically the difficulty and abrupt- ness with which the tibia reduces. Grade 0 is considered normal, with no reduction or shift noted. Grade I repre- sents a smooth glide with a slight shift; grade II is when the tibia is felt to "jump" back into a reduced position and can be described as a moderate shift; and grade III is when the tibia is transiently locked anterior to the lateral femoral condyle just before a dramatic reduction with shift. Jakob et al56 elaborated on this grading system in terms of its clinical significance. In their description, grade I occurred in internal rotation only and was appreciated as a small and gentle sliding reduction correlating with a trace shift. Grade II is positive in both internal and neutral tibial rotation, reducing with external rotation, and it is this grade that was considered to be most consistent with isolated rup- ture of the ACL. Grade III is positive in neutral tibial rotation, even more pronounced in external rotation, and moderate in internal rotation. It is seen in acutely injured knees where both the posteromedial and posterolateral corners are dam- aged.56 The pivot-shift test is illustrated in Figure 4.

Global Patellar Pressure Syndrome (GPPS)

diffuse medial/lateral soft tissue tightness, patella excessively compressed

Fat Pad Syndrome

inflammation of fat pad as a result of falling on knee

Suprapatellar Plica Syndrome

repetitive irritation of tight plica against the femoral condyle with knee flexion

What is the special test for plicas

Imaging: MRI for differential diagnosis Special testing: palpation

What are the signs and symptoms of plica inflammation

Pain in the front of the knee, often towards the inside Pain when kneeling, squatting or sitting for long periods of time Catching, locking and clicking of the knee Pain and tenderness under the kneecap

what are the special tests for patella tendonitis

Special Testing: point tenderness

Heckmann TP, Barber-Westin SD, Noyes FR. Meniscal repair and transplantation: indications, techniques, rehabilitation, and clinical outcome. J of Orthop and Sports Med. 2006; 36:795-814.

A detailed description of the surgical techniques for meniscal repair can be referenced in the article. For medial and lateral meniscus transplant, the authors preferred method is a central bone bridge technique (description of procedure in article) though other techniques are used, such as a 2-tunnel technique for medial meniscus transplant (also described in the article. The author provides a post operative rehabilitation program that is used in his clinic. Postoperative rehab begins with the initial goal to prevent excessive weight- bearing forces in order to control high compressive and shear forces that could disrupt the healing meniscus repair or transplant. Peripheral repair heals the most rapidly and radial repairs require the longest rehab period. The PT should monitor pain, gait pattern, knee flexion/extension, patellar mobility, strength, control of the lower extremity, flexibility, and tibiofemoral symptoms. Immediate postoperative management includes using bilateral axillary crutches, long-leg brace locked in extension, compression stockings, compression bandage, early control of post-op effusion, cryotherapy, elevation, and neuromuscular electrical stimulation. A brace is not usually used after a peripheral meniscal repair. Passive flexion/extension ROM is begun the day after surgery staying between 0 and 90 degrees of knee flexion and progressed throughout the rehab to 135 degrees by the 5-6th weeks. Patellar mobilization is also begun the day after surgery and continued throughout the rehab. There is also a focus on balance and proprioceptive training that begins initially with simple weight shifting and progresses to include plyometric exercises for athletic patients in later phases unless the patient underwent a transplant or has articular cartilage deterioration. Strengthening is initiated the day after surgery with isometrics, straight leg raises, and active-assisted knee extension from 90 to 30 degrees. These exercises are continued until week 3 when the patient can begin weight bearing exercises including cup walking, toe raises, mini-squats, and wall sits. These exercises are progressed using theraband and increasing depth until weeks 5 and 6 when non-weight bearing resistive training begins. For conditioning, the patient should begin using the upper body ergometer, stationary bike with raised seat, or water walking at week 2-4. The therapist should be cautious in beginning the return to sport program and ensure that the pt is ready for high intensity exercises. As far as outcome studies is concerned, the authors recommend repair of meniscal tears that extend into the central one-third of the meniscus, especially for patients who are in their 20s and 30s. They believe that preservation of meniscal tissue should be emphasized when making surgical treatment decisions. As far as meniscal transplant is concerned, short term outcomes seem to be favorable, producing decreased pain and increased function, however, long term outcomes remain a source of debate and requires further investigation.

Which findings or complaints are predictive of a bad result of an anterior cruciate ligament injury treatment? Level 2

A longer period between the occurrence of the ACL rupture and the reconstruction could increase the risk of meniscal and/ or cartilage damage (Fithian et al. 2005, Gregory and Land- reau 2008, Joseph et al. 2008, Slauterbeck et al. 2009)

Quad Strain o Pathology and MOI

A quadriceps muscle strain is an acute tearing injury of the quadriceps. This injury is usually due to an acute stretch of the muscle often at the same time of a forceful contraction or repetitive functional overloading. A quadriceps strain is characterized by inflammation and pain in the front of the thigh along the four muscles that make up the quadriceps. The muscle strain is usually due to overuse of the lower extremity or sudden increase in amount or intensity of activity. It can also stem from a single violent blow or force to the knee or the quadriceps area of the thigh.

History and clinical examination

A solid history and clinical examination are cornerstones to the diagnosis of patellar tendinopathy. Patellar tendinopathy presents subjectively as well-localized anterior knee pain related to activity levels [5,39]. Pain is usually insidious and gradual in onset, and may be precipitated by an increase in the frequency or intensity of repetitive ballistic movements of the knee. Initially pain may present as a dull ache at the beginning of or after strenuous activity. T his initial symptom may be ignored as it warms up with further activity [40]. With continued use, however, pain can progress to be present during activity and can ultimately interfere significantly with performance. In some cases there is a constant ache at rest and night pain that disturbs sleep [10,27,34]. Other common complaints are pain when seated for long periods, and when ascending and descending stairs [29]. On clinical examination, the most consistent finding is patellar tendon tender- ness [29,41]. This is typically located at the inferior pole of the patella; however, it is influenced by knee position [42]. With the knee flexed to 90° the tendon is placed under tension, and tenderness significantly decreases and may disappear altogether. Thus, the patellar tendon should be palpated in relaxed full-knee extension. Pressure on the superior border of the patella should be applied to tilt the inferior pole anteriorly, enabling palpation of the tendon origin. Using this method, pain on palpation can reliably be graded as either mild, moderate, or severe [43]. Unduesignificance should not be attached to mild pain in isolation of other signs and symptoms of patellar tendinopathy, as it may be a normal finding in active athletes [43,44]. In addition to palpation, other features to note on clinical examination are muscle size and functional strength. Patients with chronic symptoms may exhibit wasting of the quadriceps, with the vastus medialis obliquus portion most commonly affected. Overall thigh circumference may be reduced and calf atrophy may also be present. Functional strength testing of the quadriceps may be performed by asking the patient to perform 15 one-legged step-downs in which the non-weight-bearing foot is not allowed to touch the ground between cycles [45]. The work capacity of the calf can be assessed by performing single-legged heel raises. A jumping athlete should be able to perform a minimum of 40 raises [45]. During both activities the onset of fatigue and the quality of movement should be monitored, and both activities should be performed bilaterally. To reproduce symptoms of patellar tendinopathy a useful functional test is the decline (30°) squat test. This places greater load on the patellar tendon than does a squat on level ground [45]. Objective measurement during this test can obtained by determining the number of decline squats before the onset of pain, and by asking the athlete to indicate the level of pain on a visual analog or verbal reporting scale. An alternative method of objectively assessing an athlete with patellar tendino- pathy is to implement the Victorian Institute of Sport Assessment (VISA) scale [46]. This scale provides a numerical index of the severity of patellar tendinopathy by assessing both symptoms and function. A maximum score of 100 indicates full, pain-free function. The key differential diagnosis in patellar tendinopathy is patellofemoral pain syndrome. This is usually straightforward to differentiate, as the subjective and objective features of patellar tendinopathy are generally distinctive. In some cases, however, differential diagnosis may be difficult and the two conditions may coexist. One method to aid differentiation is to perform functional testing (ie, decline squat test) with and without the use of taping to influence the patellofemoral joint. At least, this may indicate whether the patellofemoral joint should also be treated. In addition to patellofemoral pain syndrome, patellar tendinopathy needs to be differentiated from fat-pad syndromes, and assessment of other potential coex- isting conditions such as meniscal tears and cartilage degeneration may need to be considered where indicated [22]. Also, the potential of pain referral to the knee should not be ignored [47].

Strengthening exercises

Although mechanical loading is implicated in the etiology of patellar tendino- pathy, loading is known to be beneficial to tendon health, and strengthening exercises are recommended in its management. Exercise may influence the struc- ture, chemical composition, and mechanical properties of a tendon [73]. Animal studies have shown loading of tendon improves collagen alignment and stimulates collagen cross-linkage formation [74]. In tendinopathy, mechanical loading may speed repair, as it increases tenocyte metabolism [75]. Clinical studies point to the efficacy of eccentric strengthening regimes in the treatment of tendinopathies [76-78]. This has been supported by recent scientific evidence [79,80], although studies in patellar tendinopathy are currently lacking [9]. Initial exercises should focus on strength and endurance gains before progressing to speed gains. Both pain and the ability of the musculotendinous unit to do work should guide the amount of strengthening activity, and during all exercises quality of movement should be emphasized.

The Posterior Lachman Test

Although the PCL has been shown to provide all of the resistance to posterior tibial translation when the knee is flexed to 90°, the posterior drawer test can be difficult to perform in the acutely injured knee because of patient dis- comfort during knee flexion.34,107 In such situations, the posterior Lachman test may be useful in diagnosing sus- pected PCL injury because the knee is only required to flex to 30°. At this angle, the PCL is still responsible for pro- viding 85% of the resistance to posterior translation.34 Recommended Technique. With the patient's knee flexed to 30°, the examiner should place his or her hands as in the posterior drawer test so that any variation in the normal relationship of the tibia and the femur can be appreciated; in the PCL-deficient knee, the tibia must be anatomically reduced at the start of this test. A posteriorly directed force is then exerted on the tibia. It is again important to main- tain neutral rotation to avoid recruitment of secondary sta- bilizers. Grading is consistent with the systems used above. One caveat for the examiner is that a slight increase in posterior translation with the knee at 30° but not at 90° may indicate a PLC injury, whereas increased translation at both positions, with maximal translation at 90°, is con- sistent with PCL injury.22

Pharmacological intervention

Anti-inflammatory agents are the most common pharmacological interventions in patellar tendinopathy, with the two most common agents being oral nonsteroidal anti-inflammatory drugs (NSAIDs) and local injection of corticosteroids. The use of both has been debated, considering that tendinopathy has a noninflammatory pathology. In a thorough review of the role of NSAIDs in the treatment of tendinopathy, Almekinders and Temple [81] found little evidence that they were helpful. In terms of corticosteroid injection directly into the tendon tissue, it has been found to inhibit collagen synthesis [82] and lead to cell death and tendon atrophy [83], and a reduction in load-to-failure [84]. Although inflammatory cells do not appear to be present in patellar tendino- pathy, inflammatory pathways may still be involved, and thus anti-inflammatory agents may have a role in management. This potential role needs to be further explored. It is possible that NSAIDs benefit tendinopathy via alternate mecha- nisms, such as accelerated formation of cross-linkages between collagen fibers [85,86]. Similarly, corticosteroids, when injected peritendinous rather than intra- tendinous, could possess beneficial effects, mediated through effects on the connective tissue and peritendinous adhesions by inhibiting the production of collagen, other extracellular matrix molecules, and granulation tissue [87].

PATELLOFEMORAL INSTABILITY

Anterior knee pain is among the most common ortho- paedic complaints and may be a manifestation of instabil- ity at the patellofemoral joint. Other symptoms of patellofemoral instability can include crepitus, buckling, swelling, difficulty climbing or descending stairs or squat- ting, and "slipping" of the patella.6 There may be a history of trauma, although patellofemoral instability can also result from congenital factors. Unlike the aforementioned ligamentous instabilities, patellofemoral instability is multifactorial, and although recent focus has been on defi- ciency of the medial patellofemoral ligament (MPFL),99 patellofemoral instability cannot be attributed to the dys- function of a single ligament or anatomic structure alone. Yet, because the symptoms and signs of a patient present- ing with acute patellofemoral instability—"my knee buck- led and swelled"—may be confused with other ligamentous injuries, consideration of patellofemoral instability within the spectrum of ligamentous instability of the knee joint is warranted. The anatomy and biomechanics of the entire lower extrem- ity must be taken into account when evaluating a patient with patellofemoral instability. In addition to targeting the dynamics of the knee joint, gait and stance must be assessed, as must varus or valgus and rotational alignment of the limb. Although it is beyond the scope of this article to describe completely the biomechanics of patellofemoral instability, some common anatomic features and selected methods of evaluation will be considered. Notably, in addi- tion, lateral facet compression syndrome and patellar tilt are not synonymous with patellofemoral instability; evaluation for signs of anterior knee pain not related to patellofemoral instability is not the purpose of this review. Factors contributing to patellofemoral joint instability may include excessive quadriceps angle (Q-angle), femoral ante- version, external tibial torsion, patella alta, femoral trochlea or patellar dysplasia, generalized laxity, pes planus, vastus medialus obliquus (VMO) atrophy, MPFL insufficiency, and genu valgum.6,35,36 The VMO is a dynamic stabilizer of the patella and acts to balance laterally directed forces on the patella at the trochlea. The MPFL is a primary soft-tissue structure that checks lateral patellar motion and is often found to be injured in a traumatic lateral patellar dislocation. Sallay et al99 described the pathoanatomy of patellar disloca- tion and reported MRI evidence of medial patellofemoral lig- ament tears in 87% of 19 patients, with increased signal intensity adjacent to the adductor tubercle in 96% and within the VMO in 78%. Bony configurations of the lateral patellar facet and the lateral femoral condyle also influence patellofemoral sta- bility. Normally, in the axial plane, the anterior lateral condylar border lies 1 cm anterior to the border of the medial condyle. Furthermore, the lateral facet of the patella is usu- ally longer and more acutely sloped than the medial facet. This contributes to static patellofemoral stability, and derangements of these features may cause patellofemoral pathology.37 The spectrum of instability ranges from patellar mal- tracking to frank, typically lateral, dislocation. Patients with "miserable malalignment" syndrome have pathologic inter- nal femoral rotation as a result of excessive femoral neck anteversion. Normally, femoral anteversion is defined as 11° with a standard deviation of 7°.53 Excessive femoral ante- version can cause the trochlea to rotate medially when the hip is placed in neutral rotation. These patients also have a large Q-angle (discussed below) produced by both associated external tibial torsion and pes planus, resulting in over- pronation. Signs of this disorder include the "bayonet sign," which refers to a sharp varus deformity of the proximal third tibia, and "squinting patellae," in which the patellae face each other when the patient's feet are held parallel.

Posterior Drawer Test

As with the anterior drawer test, the origins of this test are obscure. The posterior drawer test has been reported to be the most sensitive test in the evaluation of isolated PCL injury12,17,22,97 with a double-blind, randomized controlled study documenting 90% sensitivity. This test has also been shown to have 99% specificity for PCL injuries.98 In addi- tion, the accuracy of this test is enhanced when its findings are combined with information from other tests of poste- rior instability.79 The examiner must also be aware of the potential for false-negative results. • If tested in internal rotation, intact meniscotibial lig- aments, especially that of Wrisberg, may allow for an improvement of 1 grade. Clancy et al12 reported that the meniscofemoral ligaments (MFLs) are rarely injured with an isolated PCL tear and that they can actually eliminate the posterior drawer as they tighten in internal rotation. • Hughston48 believed that PCL rupture may be pres- ent when the posterior drawer is positive in internal rotation but that the test finding may be falsely neg- ative in an acute injury if the mechanism does not involve the arcuate complex. In such cases, a positive valgus stress test result at 0° (described below) may then be diagnostic of an acute PCL tear.34 Recommended Technique. Before dynamic evaluation of the affected knee, it is important to establish the normal relationship between the medial tibial plateau and the medial femoral condyle with the knee flexed to 90°. Pathologic posterior translation will be graded with this relationship in mind. As mentioned, the tibial plateau should normally be 1 cm anterior to the medial femoral condyle. Comparison with the contralateral, uninjured knee provides an additional measure of "normal." The patient is placed supine with the affected knee flexed to 90° and the tibia in neutral rotation. The examiner then places both hands along the anterior aspect of the proxi- mal tibia with the thumbs lying on the anterior joint line of both the medial and lateral compartments. A posteriorly directed force is applied equally with both hands and graded based on the amount of pathologic posterior tibial translation that occurs. Hughston et al51 suggested that a negative posterior drawer test finding with the tibia in neutral or internal rotation can help to rule out PCL injury and that performing the posterior drawer test with and without internal tibial rotation can be useful in distin- guishing a positive result for posterolateral rotatory sub- luxation from a positive result for a PCL tear, as rotatory instability may sometimes be appreciated in the internally rotated knee.51 As with many other tests, grade I PCL laxity is consis- tent with translation of 0 to 5 mm (and the tibial plateau remains anterior to the femoral condyle). Grade II is clas- sified by posterior translation of 6 mm to 10 mm (which correlates with the tibial plateau being flush with the femoral condyle). Grade III injuries measure >10 mm of posterior translation (and allow the tibial plateau to trans- late posterior to the femoral condyle). The quality of the endpoint is also graded as "firm, soft, or absent." Shelbourne et al100 pointed out that the endpoint may return to firm within the first 2 weeks after a PCL tear as a result of intact supporting structures. In these circum- stances, or when evaluating chronic injuries, translation can be considered more reliable than the endpoint in the assessment of PCL status. The posterior drawer test is illustrated in Figure 5.

Surgical treatment— which kind of graft gives the best result in an anterior cruciate ligament reconstruction? level 1

Bone-patella-tendon-bone and hamstring grafts both give similar degrees of stability when used in conjunction with modern (extra-cortical) fixation techniques (Schultz and Carr 2002, Goldblatt et al. 2005, Prodromos et al. 2005, Thompson et al. 2005). The use of a bone-patella-tendon-bone autograft has a greater chance of giving anterior knee pain than the use of a hamstring autograft. There is no substantial difference between hamstring or bone-patella-tendon-bone reconstruc- tion, in muscle strength of the flexors and extensors of the knee 2 years after surgery (Freedman et al. 2003, Dauty et al. 2005, Forster and Forster 2005, Goldblatt et al. 2005)

Patellofemoral Instability

Description instability of patella causing it to have excess glide in the medial or lateral directions (usually lateral) and often causing anterior knee pain Mechanism of Injury could include: excessive Q-angle, femoral anteversion, external tibial torsion, patella alta, femoral trochlea or patellar dysplasia, generalized laxity, pes planus, VMO atrophy, MPFL insufficiency, genu valgum Special diagnostic tests Q-angle assessment; Assessment of patellar tracking; assessment of J-sign (abrupt or extreme lateral shift of the patella during active extension); Manual translation test: Apprehension test

Conservative treatment

Despite the morbidity associated with chronic patellar tendinopathy, there is a surprising lack of scientific evidence directing the management of this condition. This lack of evidence results from a dearth of methodologically sound, random- ized-controlled trials of clinically implemented treatments, and has resulted in vastly contrasting treatment choices among clinicians. In spite of this, what is currently agreed upon is that initial management should be conservative rather than surgical. This reasoning is based on the facts that the time course of recovery with appropriate conservative management is equivalent to that following surgery, and that the outcome of conservative management is equal to, if not better than, that following surgery [2]. For appropriate conservative management, the aforementioned underlying pathology of patellar tendinopathy needs to be understood by both the treating clinician and athlete. The pathology is degenerative by nature and this degeneration was most likely taking place before the onset of symptoms. This means that the pathology is typically quite advanced before clinical presentation. The advanced degeneration before the onset of symptoms, combined with the slow metabolic rate of tendon, means that recovery can be prolonged. In chronic cases, this recovery can take in the vicinity of 4 to 6 months [2]. In athletes with a short duration of symptoms, recovery to full sporting capacity may take 2 to 3 months [2]. It is with these latter athletes that special care needs to be taken, as they may be able to warm up the injury, enabling full sporting capacity, further mechanical overload, and further tendon degeneration. The focus of any conservative management program should be to deload the tendon and to encourage collagen synthesis, maturation, and strength [2]. At all times, progression through the program should be directed by the athlete's symptoms. Common reasons why conservative treatment programs fail are too rapid a progression through rehabilitation, lack of monitoring of an athlete's symptoms during and after therapy, and inappropriate loads [45]

POSTERIOR INSTABILITY

Excessive posterior translation of the tibia on the femur is prevented primarily by the PCL and secondarily by the posterolateral corner (PLC), LCL, and MCL.12,15,16,27,39,105 Damage to the PCL may occur by several different mecha- nisms, including both low-energy and high-energy injuries in which a posteriorly directed force is applied to the prox- imal tibia of a flexed knee. This may happen when an ath- lete falls with the foot in plantar flexion or as a result of a "dashboard injury" during a motor vehicle accident. Hyperextension of the knee can also rupture the PCL, and this scenario is associated with a high likelihood of knee dislocation and injury to other ligaments.12,18,30,31,33,57 Symptoms of PCL deficiency include pain, stiffness, and swelling in the knee. Instability is occasionally noted but with less frequency than in ACL deficiency.18 Although PCL injuries may occur in isolation, they are usually part of a complex injury, with PLC involvement occurring in 60% or more cases of PCL tears.30 Clinical tests that reveal excessive posterior tibial translation include the posterior drawer, posterior Lachman, and posterior sag tests. The quadriceps active test demonstrates pathologic, dynamic anterior tibial translation in the setting of a PCL tear with sag. Some research indicates that in patients with chronic PCL injury, the sensitivity of these clinical tests increases when the ligament sprain is at least grade II.98 Multiple cutting studies have shown that isolated sec- tioning of the PCL results in increased posterior transla- tion of 15 mm to 20 mm, occurring maximally at 90° of knee flexion.16,63 The tensile strength of the PCL is almost twice that of the ACL, and the load-bearing capacity, stiff- ness, and size of the anterolateral (AL) bundle of the PCL are greater than that of both the posteromedial (PM) PCL bundle and the meniscofemoral ligaments, suggesting that the AL bundle is primarily responsible for the biomechan- ical properties of the PCL.45,63 Without additional damage to the PLC, isolated sectioning of the PCL has no effect on internal or external rotation, nor is there any increase in varus or valgus opening.16,63 Consequently, the most appro- priate test for evaluating isolated PCL injury is a test that assesses posterior tibial translation alone.

What are the signs and symptoms of MCL tear

Grades • Grade I MCL Tear: This is an incomplete tear of the MCL. The tendon is still in continuity, and the symptoms are usually minimal. Patients usually complain of pain with pressure on the MCL, and may be able to return to their sport very quickly. Most athletes miss 1-2 weeks of play. • Grade II MCL Tear: Grade II injuries are also considered incomplete tears of the MCL. These patients may complain of instability when attempting to cut or pivot. The pain and swelling is more significant, and usually a period of 3-4 weeks of rest and rehab is necessary. • Grade III MCL Tear: A grade III injury is a complete tear of the MCL. Patients have significant pain and swelling, and often have difficulty bending the knee. Instability, or giving out, is a common finding with grade III MCL tears. A knee brace or a knee immobilizer is usually needed for comfort, and healing may take 6 weeks or longer.

Heterotrophic ossificans o Pathology and MOI

Heterotopic ossification (HO) describes bone formation at an abnormal anatomical site, usually in soft tissue. HO can be classified into the following 3 types: 1) Myositis ossificans progressive, which is a genetic disorder; 2) Traumatic myositis ossificans, which results from a direct blow to the area or a muscle tear, and 3) neurogenic heterotopic ossification, which can come from a traumatic spinal cord injury

Reinold MM. Solving the patellofemoral mystery. 2010; 1-35.patellofemoral

Hip and foot abnormalities can highly influence patellofemoral joint mechanics, therefore, the entire kinetic chain must be evaluated. Due to the tendency for hip weakness to cause hip add/IR and valgus at the knee, it is important to strengthen hip abd and IR. Ankle foot abnormalities, such as pronation, leg length discrepancy, and supination can also alter mechanics at the patellofemoral joint and should be corrected or accounted for with orthotics.

IT Band Friction Syndrome o Pathology and MOI

IT band friction syndrome is caused by excessive friction of the IT band and the underlying bursa due to repetitive knee-bending activities. This is an overuse injury, although direct trauma to the outer knee may cause the bursa to get inflamed. Often the deceleration of running down hills may lead to the excessive friction

Cryotherapy

Icing may have a role in the management of patellar tendinopathy, particularly when applied post-loading. Icing reduces blood flow and may help to reduce the pathological neovascularization associated with tendinopathy. Whether it also reduces tenocyte collagen production requires consideration. Icing may also be used as an analgesic; however, this role should only be used following exercise, as it may mask symptoms enabling tissue overload

Imaging

Imaging can be used to confirm the clinical diagnosis of patellar tendinopathy with the techniques of choice being ultrasonography and magnetic resonance imaging (MRI). Both provide excellent anatomic representation of the patellar tendon, and histopathologic studies have shown that the characteristic tendino- pathy appearances observed with both forms of imaging are due to the underlying tendon pathology [10,14,19,26,48,49]. Ultrasonography Ultrasonography provides a readily available, quick, and inexpensive method of imaging the patellar tendon. The tendon is readily examined using high-frequency linear array transducers with the knee flexed or semiflexed, and by obtaining both longitudinal and transverse images [50]. In suspected cases of patellar tendino- pathy, ultrasonography can be used to confirm the existence and location of intratendinous lesions. These lesions are reflected by decreased echogenicity, evident by either diffuse hypoechogenicity or a focal sonolucent region, typically in the deep posterior portion of the tendon adjacent to the lower pole of the patella [8,10,27,39,50 - 55] (Fig. 1). The decrease in echogenicity represents a decrease in the ultrasound attenuative properties of the tendon, resulting from the disruption of the collagen bundles. Other common findings on ultrasonography include tendon thickening [8,24,27,44,53,56], irregularity of the tendinous envelope [8,53], intratendinous calcification [8,24,44,51,57,58], and erosion of the patellar tip [8]. The primary disadvantages of ultrasonography are its operator-dependency and somewhat limited soft-tissue contrast [40]. Magnetic resonance imaging MRI provides high spatial resolution that allows detailed anatomic structures to be identified, and it provides high intrinsic tissue contrast that allows normal tendons to be distinguished from abnormal tendons. On MRI, patellar tendinopathy is characterized by a focal increase in signal within the tendon as well as an alteration in its size [14,19,26,27,32,34,59,60]. The later is necessary with some sequences, as the ''magic angle'' phenomenon associated with MRI can artificially increase signal intensity, resulting in false-positive findings et al [59] suggest an anteroposterior diameter cutoff point of 7 mm between symptomatic and asymptomatic tendons; however, more recent authors have shown considerable overlap and variation in tendon thickness [34,64,65]. The primary disadvantages of MRI are its relatively high cost, limited availability in some regions, and lengthy time for scanning. Limitations of imaging Although both ultrasonography and MRI are useful in imaging patellar tendinopathy, neither can be labeled as the gold standard for its diagnosis. Positive ultrasonography and MRI images for patellar tendinopathy have been shown in asymptomatic tendons [10,39,44,51,58,60,65-69]. Similarly, symptomatic ten- dons can have the imaging appearance of normal asymptomatic tendons [32,39,43,44,54,69]. Using currently available data, the sensitivity and specificity of ultrasonography can be calculated at 58% and 94%, respectively (Table 1). For MRI, the sensitivity and specificity can be calculated at 78% and 86%, respectively (Table 2). Thus, although ultrasonography and MRI may accurately reflect tendon morphology, the imaging appearance may not necessarily reflect clinical symp- toms. Further confirming this, numerous authors have shown no correlation between the severity of tendinopathy symptoms on clinical grading systems and tendon appearance on ultrasonography [44,57,68]. In addition to being unable to reflect clinical symptoms, ultrasonographic and MRI appearances cannot be used to distinguish outcome following intervention for tendinopathy. Ultrasound images remain both qualitatively and quantitatively abnormal 12 months after surgery, even in athletes who have returned pain-free to full competition [24]. With longer follow-up after surgery, no correlation exists between the area of the hypoechoic region and either function or time after surgery [57]. In terms of MRI, tendon appearance does not return to normal after successful surgery, and thus it is not able to distinguish patients whose surgical outcome was excellent from those whose outcome was poor [24]. Consequently, imaging does not appear to have a major role to play in monitoring outcomes following intervention for tendinopathy. As tendons can have asymptomatic lesions on imaging, and these lesions in symptomatic tendons have been shown to be an area of histological degeneration, it is reasonable to question whether imaging can be used to predict future prognosis. At this stage this is not completely clear, although based on current longitudinal data using ultrasonography a trend does appear (Table 3). In one study, a 4.2 times greater risk of developing symptoms was identified in asymptomatic tendons with imaging abnormalities than in those without such abnormalities [51]. Because asymptomatic tendinosis can lead to spontaneous tendon rupture [23], the rele- vance of asymptomatic lesions on imaging needs further investigation. As imaging does not reflect symptoms or indicate outcome, it remains a supplemental aid to clinical examination in the assessment of patellar tendino- pathy. Imaging is very sensitive to abnormal tendon morphology [24]. Given thehigh positive-predictive value of imaging (Tables 1,2), it is of use in patellar tendinopathy, as it can confirm the clinical diagnosis and increase the overall likelihood of diagnosis. If imaging reveals characteristic features of patellar tendinopathy that fit the clinical presentation, then treat as such; however, if imaging is normal, then other causes of anterior knee pain need to be further considered. Imaging should not be used to determine management, and it does not appear to have a major role postoperatively. Whether imaging findings in asymptomatic tendons are predictive of future prognosis should be a focus of further research.

What is the management for patella tendonitis

Management Initial treatment starts with ice and NSAIDS to relive pain and inflammation. Then stretching and strengthening of the quadriceps and hamstring muscles are required. It is also recommended to modify active that causes pain. An arch support or a patellar tendon brace may be prescribed to reduce stress to the tendon.

what are the special tests for quad strain

Manual muscle test to assess quadriceps strength

Which patient-related outcome measures should be used for the evaluation and follow-up of patients with anterior cruciate ligament injury? Level 1:

Performance of a complete physical examination of the knee (Lachman, pivot shift, and anterior drawer test) has a higher sensitivity and specificity than performing a partial examina- tion (Solomon et al. 2001, Scholten et al. 2003, Benjaminse et al. 2006).

what are the special tests/images for PFPS

Radiography is recommended in patients with a history of trauma or surgery, those with an effusion, those older than 50 years (to rule out osteoarthritis), and those whose pain does not improve with treatment.

What is the management of PFPS

Recent research has shown that physical therapy is effective in treating patellofemoral pain syndrome. There is little evidence to support the routine use of knee braces or nonsteroidal anti-inflammatory drugs. Surgery should be considered only after failure of a comprehensive rehabilitation program. Educating patients about modification of risk factors is important in preventing recurrence.

ROTATORY INSTABILITIES

Rotatory instabilities primarily affect knee function in flexion. Gait analysis indicates that during normal walk- ing, the knee flexes between 0° and 20°, whereas during running, knee flexion increases in direct proportion to rate. In full extension and maximum weightbearing, no rotation is present (neutral rotation). External rotation of the tibia relative to the femur commences with knee flexion, with maximum rotation occurring between 60° and 90° of flex- ion.71 Isolated rotatory instabilities may manifest during cutting, pivoting, or rapid deceleration activity in a man- ner similar to combined ligamentous instability, and mul- tiple directions of rotatory instability may also present.7

The Influence of the Hip on Patellofemoral Pain

The influence of the hip on the patellofemoral joint has been well documented over the last decade. The biomechanical works of Dr. Powers have shown that excessive hip adduction and internal rotation places the patellofemoral joint in a disadvantageous position. Unfortunately, our population is dominated by sagittal plane strength and weakness in the coronal and transverse planes. It seems like it is a normal part of daily living now as the majority of our functional tasks take place in the sagittal plane. Even more unfortunate is the fact that exercises outside of the sagittal plane are often neglected in rehabilitation and strength training programs. This creates a significant biomechanical disadvantage. To fully understand the significance of this, imaging the weightbearing knee. When the hip moves into adduction and internal rotation while the foot is planted, the femur will change position around a relatively stable patella (there is movement, just using this as an example). It is the reverse concept that is commonly seen in patellofemoral rehabilitation. The movement, or "tracking" of the patella on the femur is less relevant in this weightbearing position. It is the movement of the femur on the patella that is significant. Below is an example of how the femurs moves on the patella in the weightbearing position, note the patella is fairly stable while the femur rotates internally: This is likely the mechanism of patellar subluxations and dislocations and the cause of wear and tear of the joint. Patients often describe an injury that occurs when planting and pivoting or planting on an unstable surface. The quadriceps contracts to stabilize the knee while the femur is adducted and internally rotated, resulted in a lateral displacement of the patella in relation to the femur. This can cause an acute injury as well as degeneration over time. A recent study by Dr. Powers in JOSPT showed that females with patellofemoral pain had greater hip rotation during running, jumping, and stepping down. This also lead to subsequent decrease in hip strength. In fact, another study by Dr. Powers' group published in AJSM demonstrated that patellofemoral pain in women is the results of decreased hip strength not anatomical variations (wider hips, etc.). Treatment of these patients requires training the hip to abduct and externally rotate. Also, it is important to train the hip abductors and external rotators to isometrically stabilize the knee during sagittal plane movements and to eccentrically control hip adduction and internal rotation. A simple test I perform is the step-down exercise. I am specifically looking for the ability to eccentrically lower the body in the sagittal plane while preventing the hip from dipping into adduction and internal rotation. This is harder than it looks and will often be an issue in your patients. But trust me, overtime this will improve, and POOF! Your patient's patellofemoral pain while climbing stairs and running will have vanished! You are a genius now, the last three times she went to rehabilitation elsewhere they perform ultrasound on her knee and had her squeeze a ball between her knees during mini-squats to "strengthen her VMO." Which brings up a great topic, do you still want to squeeze that ball between your knees and emphasize hip adduction and internal rotation? I would actually recommend just the opposite. I frequently use a piece of Theraband (or even those new knee resistance straps that Theraband just started making) around the patient's knees during exercise. This will require the patient to isometrically control the hip from adducting and internally rotating while performing mini-squats, wall squats, leg press, and other sagittal plane exercises

4. Emphasize the Quadriceps

The next principle of patellofemoral rehabilitation is to strengthen the knee extensor musculature. Some authors have recommended emphasis on enhancing the activation of the VMO in patellofemoral patients based on reports of isolated VMO insufficiency and asynchronous neuromuscular timing between the VMO and VL. While the literature offers conflicting reports on selective recruitment and neuromuscular timing of the vasti musculature, the VMO may have a greater biomechanical effect on medial stabilization of the patella than knee extension due to the angle of pull of the muscle fibers at approximately 50-55 degrees. Wilk et al(JOSPT 1998) suggest that the VMO should only be emphasized if the angle of insertion of the VMO on the patella is in a position in which it may offer a certain degree of dynamic or active lateral stabilization. As you can see by the figure, if the fibers are not aligned in a position to assist with patellar stabilization, VMO training will likely not be effective. This orientation of the muscle fibers will differ from patient to patient and can be visualized. Several interventions and exercise modifications have been advocated to effectively increase the VMO:VL ratio, based mostly on anecdotal observations. These include hip adduction, internal tibial rotation, and patellar taping and bracing. Powers(JOSPT 1998) reports that isolation of VMO activation may not be possible during exercise, stating that several studies have shown that selective VMO function was not found during quadriceps strengthening exercises, exercises incorporating hip adduction, or exercises incorporating internal tibial rotation. Powers also states that although the literature offers varying support for VMO strengthening, successful clinical results have been found while utilizing this treatment approach. My belief is that quadriceps strengthening exercises should be incorporated into patellofemoral rehabilitation programs. Strength deficits of the quadriceps may lead to altered biomechanical properties of the patellofemoral and tibiofemoral joints. Any change in quadriceps force on the patella may modify the resultant force vector produced by the synergistic pull of the quadriceps and patellar tendons, thus altering contact location and pressure distribution of joint forces. Furthermore, the quadriceps musculature serves as a shock absorber during weightbearing and joint compression, any abnormal deviations in quadriceps strength may result in further strain on the patellofemoral and/or tibiofemoral joint. In reality, I believe that quadriceps strengthening is very important for patellofemoral rehabilitation, but many exercises designed to "enhance VMO" strength or activation may actually be disadvantageous to the joint. Take for example the classic squeezing of the ball during closed kinetic chain exercises such as squatting and leg press. This creates an IR and adduction moment at the hip that is now known to be detrimental to patellofemoral patients. I would actually propose that we work on quadriceps strengthening without an adduction component and rather emphasize hip adbuction and external rotation. This can be performed with the use of a piece of exercise band around the patient's knees during these exercises. We will get into this in more detail in an upcoming post in this series.

Suprapatellar plica syndrome.

The plica is an interesting and debatable structure. I have always been of the belief that plica is very individual and some people have larger synovial folds than others. Most common is the suprapatellar plica, which is located medial and superior to the patella. This structure gets tight against the femoral condyle as the knee flexes so repetitive activities such as bike riding can cause this.

Pathogenesis

To prevent patellar tendinopathy and to develop appropriate treatment strategies when it does occur, an understanding of the pathogenesis is required. Unfortu- nately, the precise mechanism by which patellar tendinopathy develops is currently unknown. As with most overuse conditions, the development of patellar tendino- pathy is likely to be due to a range of factors, with the relative contribution of each factor varying among individuals. These factors can be grouped into two catego- ries: extrinsic and intrinsic. Extrinsic factors are the most commonly indicted in the pathogenesis of patellar tendinopathy, with the most frequently reported causative factor being mechanical overload. For patellar tendinopathy to develop, repeated heavy loading of the tendon is required [6,29]. This explains its prevalence in sports involving some form of jumping, such as basketball and volleyball. In volleyball, a direct rela- tionship exists between the number of training sessions (number of jumps) and the development of patellar tendinopathy [6]. As the characteristic lesion in patellar tendinopathy typically occurs in the deep posterior portion of the patellar tendon adjacent to the lower pole of the patella, it has been hypothesized that loading exposes this region to the most strain. This hypothesis has contrasting evidence, with two cadaver studies reporting opposing results [30,31]. One found greater strain in the anterior portion of the tendon [30], whereas the other reported greater strains in the posterior portion [31]. Although the latter study did find evidence to support the hypothesis of greater strains in the posterior portion of the tendon, the authors also found the posterior portion of the patellar tendon to be more adapted to loading, as evident by its enhanced mechanical properties. Thus, it is not clear whether patellar tendinopathy is purely a strain-related phenomenon. Although extrinsic factors may be the most consistent causative factor in the development of tendinopathy, the development of patellar tendinopathy in some athletes while others with equivalent loading are spared signals that intrinsic factors must also contribute. Johnson et al [32] hypothesized that impingement of the inferior pole of the patella onto the tendon may contribute to the pathogenesis. This is supported by the findings of altered patella anteroposterior tilt [33] and a long inferior pole [18,34] in many knees with tendinopathy. Recent research, however, found no difference between symptomatic and asymptomatic knees in terms of the tendon-patella angle during flexion, suggesting that impingement is not an important contributing factor [35]. The long inferior pole found in some symp- tomatic athletes may merely represent a traction osteophyte caused by repeated high-tensile forces in this area [34], and may not have been a pre-existing contributory abnormality. Other intrinsic factors that have been postulated as causes of patellar tendino- pathy include malalignment, patella alta, abnormal patellar laxity, and muscular tightness and imbalance [36]. Of these, only muscle tightness has prospectively been shown to be a predisposing factor. In particular, Witvrouw et al [36] found decreased flexibility of the quadriceps and hamstring muscles to be significantly associated with the subsequent development of patellar tendinopathy. How extrinsic and intrinsic factors combine to trigger the generation of patellar tendinopathy is not established. It is possible that the pathological changes are initially triggered by matrix changes. Heavy loading may cause tensile failure of tendon fibers, resulting in microdamage. When this occurs, tenocytes must increase their production of collagen and matrix. This is a slow process, however, due to the inherently slow turnover rate of collagen. With further loading, an area of tendinosis may develop due to progressive microdamage and subsequent failed healing attempts. An alternative to matrix-mediated changes is the possibility of cellular-triggered pathological changes. Recent research has shown a direct relationship between the amount of stress that tendon cells are exposed to and the induction of a stress- activated protein kinase, c-Jun N-terminal kinase (JNK) [37]. Although transient activation of JNK is associated with normal cell processes, persistent JNK activation has been linked to the initiation of programmed cell death or apoptosis. Although yet to be shown in patellar tendinopathy, increased cellular apoptosis has been shown in supraspinatus tendons with tendinosis [38].

What is the optimal postoperative treatment (after the first postoperative check-up, concerning rehabili- tation, resumption of sports, and physiotherapy)? Level 1

Wearing of a knee brace has no additional treatment value after an ACL reconstruction (Wright and Fetzer 2007, Ander- son et al. 2009). In the early phase of rehabilitation, closed-chain exercise therapy is likely to give fewer patello-femoral complaints and less laxity than open-chain exercises (Trees et al. 2005, Wright et al. 2008, Anderson et al. 2009)

Apophysitis

avoid provoking activity, allow time for healing

Direct Patellar Trauma

bone bruises, articular cartilage lesions, fractures caused by direct trauma

Patellar Instability

excessive patellar mobility laterally, often shallow trochlea

Direct Patellar Trauma

frequent PROM, bike, pool, limit patellofemoral JRF exercises

Heckmann TP, Barber-Westin SD, Noyes FR. Meniscal repair and transplantation: indications, techniques, rehabilitation, and clinical outcome. J of Orthop and Sports Med. 2006; 36:795-814.

he meniscus of the knee serves many important functions such as load transmission across the knee joint, shock absorption, joint nutrition, contribution to knee joint instability, and proprioception. Therefore, it is vital that a total meniscectomy be avoided unless all other options are considered to be insufficient in repairing the structure. Traditionally, repair was not considered if a tear extended 4 to 5 mm beyond the peripheral meniscal rim, but there has been recent success in repairs of the central one-third avascular zone of the meniscus. The gold standard and author's preferred method remains to be arthroscopic assisted suture repair. An examination of a patient with a suspected meniscus injury includes a comprehensive examination of the knee, McMurray test, and diagnostic imaging (plain radiograph, spiral CT arthrography, and MRI). Signs and symptoms of a meniscal tear include, pain, swelling, giving way, limitations of daily activities, and characteristics tibiofemoral joint pain on palpation during knee flexion activities. Following are indications and contraindications of surgical meniscal repair and transplant:

Patellar Compression Syndromes (ELPS, GPPS, Patellar Instability)

heat; continuous ultrasound to tight area; soft tissue massage, trigger point and muscle energy techniques; patellofemoral joint mobs; conservative strengthening; patellar taping(ELPS only); generalized stretching; avoid biking, exercises with high PF JRF, taping pt's with GPPS

Medial patellofemoral ligament injury.

his was previously discussed above, but realize that any issues with chronic ELPS or patellar instability will cause MPF ligament pathology.

IT band friction.

imilarly, ITB friction can occur laterally as the patellar tract of the IT band gets taught against the lateral femoral condyle during flexion.

Patellar Tendonitis

inflammation of tendon at inferior pole or less commonly at mid tendon or tibial tuberosity

Apophysitis

injury to growth plates of tibial tuberosity (osgood-schlatter) or inferior patellar pole (Sindig-Larsen-Johansson)

Why is there controversy in the literature regarding a ''valgus collapse'' mechanism?

n a recent review paper, Yu and Garrett18 disputed the idea that knee abduction could be associated with isolated ACL injury. They argued that ''valgus'' cannot cause ACL injuries, because they believe that the ACL is not the major load-bearing structure during valgus loads. Yu and Garrett18 also questioned the validity of our prospective coupled biomechanical-epide- miological studies that demonstrated that knee abduction was a strong predictor of future non-contact ACL injury risk in female athletes. However, we did not claim that the ACL injury was caused by a ''pure'' valgus mechanism. Our experimental analysis demonstrated a strong and clear association between prospectively measured variables, knee abduction motion and torque, and subsequent ACL injuries in female athletes. These observations may be interpreted in different ways, but the statistical and clinical significance of this association is well established in the peer-reviewed literature. Yu and Garrett18 may be correct in supporting a primarily ''sagittal plane'' ACL injury mechanism for male athletes. However, ignoring the increasing evidence for valgus collapse as a mechanism for injury, especially in female athletes, could seriously impede ACL injury intervention efforts if dangerous frontal plane biomechanics are ignored in prediction and prevention programmes.

Excessive Lateral Pressure Syndrome (ELPS)

patella over-constrained by tightness of lateral retinacular tissue causing lateral tilt and decreased medial glide and stretch of medial retinacular tissue

Suprapatellar Plica Syndrome

stop activity causing pain, direct anti-inflammatory modalities, avoid repetitive flexion, biking, running

Fat Pad Syndrome

stop activity causing pain, direct anti-inflammatory modalities; avoid excessive quadriceps activity

Medial Patellofemoral Ligament Injury

stop activity causing pain, direct anti-inflammatory modalities; treatment similar to ELPS; brace to control lateral patellar translation

IT Band Friction

stop activity causing pain; direct anti-inflammatory modalities; lengthening massage to IT band

what are the signs and symptoms of osgood schlatter disease

A slightly swollen, warm and tender bump below the knee Pain with activity especially straightening the leg against force Pain during vigorous activity Pain with jumping, deep knee bends or weight lifting

What are the special tests/images of HO

Imaging: Radiographs, bone scans, biopsy, lower limb angiography

What are the special test/images for patella dislocation

Imaging: X-ray before and after relocation

What are the signs and symptoms patella tendonitis

Pain, tenderness, swelling, warmth or redness over the patellar tendon Loss of strength with forcefully straightening the knee Pain with jumping Crepitation when the tendon is moved or touched

What are the signs and symptoms for quad strain

Pain, tenderness, swelling, warmth or redness over the quadriceps muscle Pain that is worse during and after strenuous activity Muscle spasm in the thigh Pain or weakness with running, jumping or straightening the knee Crepitation Possible bruising

what are the special tests/images for PCL tear

Special Testing: Posterior drawer, Posterior Sag, check dial test Imaging: MRI

What are the special tests/images LCL teat

Varus stress test MRI

what is the management for OSD

Management Initial treatment starts with ice and NSAIDS to relive pain and inflammation. Then stretching and strengthening of the quadriceps and hamstring muscles are required. It is also recommended to modify active that causes pain. Avoid kneeling, jumping, squatting, stair climbing, and running on the affected knee. A patellar band may help to relieve symptoms.

VARUS INSTABILITY

The LCL is the major restraint to varus instability at all flexion angles and is secondarily supported by the PLC. Injury to the LCL results from excessive varus stress and rarely occurs in isolation. Rather, injury to other ligaments usually accompanies an LCL tear. Symptoms vary, depend- ing on the involvement of the PLC and the severity of the injury. Pain on weightbearing or lateral movement and/or the perception of knee instability during the stance phase of gait may be manifestations of varus instability.18 Only small increases in varus rotation are seen with iso- lated LCL sectioning, with the greatest increase occurring at 30°. This amount, however, may be too subtle to be appreciated on clinical examination.110 When the LCL and the lateral deep ligament complex are sectioned together, there is a significant increase in varus rotation at all flex- ion angles, again with the maximum occurring at 30°. A large degree of varus instability at full extension may indi- cate a combination injury of LCL injury plus the PLC, ACL, or PCL insufficiency.39,108-110 Isolated cruciate injuries have been shown not to affect varus or valgus stability

What are the management of quad strain

The RICE principle should be applied immediately following the injury. The quadriceps should be iced with the knee bent to ensure muscle elongation and decrease the likelihood of muscle spasm. Activity also needs to be modified. An elastic bandage or neoprene sleeve may help reduce swelling and reduce symptoms

Posteromedial Rotatory Instability (PMRI)

This is a least common form of rotatory instability, pro- duced by concomitant valgus force and hyperextension of the knee, which lead to injury of the medial capsular liga- ment, tibial collateral ligament, POL, and ACL. When these structures are damaged, the proximal medial tibia sags posteriorly. This sag will only occur in the context of an intact PCL, which supplies a rotational axis for pathologic posteromedial shift. If the PCL is torn, the entire tibia will be displaced posteriorly. Posteromedial rotatory instability may be discerned clinically when the medial tibial plateau shifts posteromedially when valgus stress is applied.

What are the signs and symptoms of patellofemoral pain syndrome

Pain behind or around the patella Pain that is increased with running and activities that involve knee flexion

What are the signs and symptoms of ITB

Pain, tenderness, swelling, warmth, or redness over the IT band Initially, pain at the beginning of an exercise that lessens once warmed up Eventually, pain will continue throughout activity worsening as the activity continues Pain that is worse when running down hills or stairs Pain that is felt most when the foot of the affected leg hits the ground Possibly, crepitation when the tendon or bursa is moved or touched

What are the special tests/images for ITB

Special testing: Ober's test, Noble's compression, Renne's test

what are the special tests/images osgood schlatter disease

X-rays

Summary of Readings for Week 6

"Patellofemoral pain syndrome" is a term that encompasses a vast array of patellofemoral joint disorders that have been a source of perplexity with little to no consensus on optimal management in orthopedics and sports medicine. This article attempts to provide some clarity and direction in diagnosis and treatment of these complex pathologies. It has been proposed that in a majority of patients being seen for patellofemoral pain, the origination of the symptoms is not in the osseous or articular cartilage structures, but rather the surrounding soft tissue. Therefore, with the understanding that the source of pain is multifactorial, it is necessary to seek out an accurate and specific diagnosis with an understanding of the cause of the symptoms rather than resorting to the use of the obscure "patellofemoral pain" description. The following are classifications of patellofemoral pain syndrome as well as treatment recommendations for each.

VALGUS COLLAPSE MECHANISM: A MORE RECENT DISCOVERY AND PROBABLE MECHANISM OF INJURY IN WOMEN

''Valgus'' refers to the outward angulation of the distal segment of a bone or joint. At the knee joint, valgus may occur from a pure abduction motion of the distal tibia relative to the femur or from transverse plane knee rotation motions (femoral/tibial internal and external rotations). Hollis and colleagues28 described the axial rotation of the tibia relative to the femur during a ''valgus'' load application and found that at increasing knee flexion angles, the internal tibial rotation increased with a maximum of up to 21u of rotation at 90u of flexion. Therefore, describing an injury mechanism as a valgus collapse does not necessarily indicate that the injury occurs solely in the frontal plane and contributions of other planar movements should also be considered.

WHAT IS THE INCITING EVENT IN NON-CONTACT ACL INJURY?

A great deal of controversy and current research surrounds the inciting event and the biomechanical mechanisms underlying non-contact ACL injury. Whereas the intrinsic and extrinsic risk factors for ACL injury have been explored extensively, the factors surrounding the inciting event and the biomechanical mechanisms underlying non-con- tact ACL injury require greater analysis. Methods to describe ACL loading and injury mechanisms have included athlete interviews, in-vivo arthro- scopic, clinical, video analysis, cadaveric, motion analysis, electromyographic and mathematical modelling studies. However, these studies have provided contradictory and inconclusive results and thus widely varying interpretations as to the inciting event.9 Observational studies indicate that most non- contact ACL injuries occur during lateral pivoting, landing or deceleration manoeuvres during sports play.11 However, the planes of knee motion that lead to non-contact ACL injury are not completely clear and remain a controversial issue in the literature. Video studies of ACL injuries provide evidence that supports two predominant loading patterns: injury as a result of knee valgus collapse (a combination of knee valgus, hip internal rotation and tibial rotation) or by anterior tibial shear (although the biomechanical evaluation of anterior tibial shear by video analysis is difficult).9- 13 The ACL provides approximately 85% of the knee joint's total restraint to anterior tibial translation at 20-30u of knee flexion14-17 and as studies have shown that sagittal plane knee angles near full extension and large quadriceps muscle forces increase ACL loading, many clinicians support a predominantly sagittal plane ACL injury mechanism.18 In contrast, pure frontal (valgus- varus) or transverse (internal-external) plane knee loads have a less obvious effect on ACL strain, and the MCL, not the ACL, is reportedly the primary restraint against valgus stress in the knee joint.14 19 In contrast to this accepted dogma, both in-vivo biomechanical data and video analyses indicate that increased lower extremity valgus loads and movements in the frontal plane are probably associated with an increased risk of ACL injury.11 20 21 Although the ACL may be subject to large forces during various loading conditions,22 load sharing among knee joint ligaments is complex and there is strong evidence that non-contact ACL injuries likely occur as a result of increased motion and loading in the sagittal, frontal, transverse and/or multiplanar conditions.9-11 22-27 The purpose of this review is to highlight the evidence for a frontal plane (''valgus collapse'') mechanism, because of its important implications for relative risk prediction and ACL intervention programmes.

Electrophysical modalities

A range of electrophysical modalities have been employed to treat patellar tendinopathy. These include ultrasound, laser, and electrical stimulation. Currently there is only circumstantial evidence supporting the use of these modalities and further research is required. Ultrasound can stimulate in-vitro collagen production from fibroblasts [88,89], and increases mechanical strength return during repair of acute tendon injuries [90,91]. Laser has been shown in a rabbit Achilles tenotomy model to increase collagen content [92]. Biomechanical and biochemical measures of tendon healing were improved by a combination of ultrasound, laser, and electrical stimulation of rabbit Achilles tendons after tenotomy and suture repair Whether beneficial effects of these modalities are present in degenerative patellar tendinopathy and in humans has not been investigated.

What is the management of patella dislocation

After immediate reduction treatment consists of ice and medications to relieve pain. Reduction can be performed without surgery although surgery may be necessary to remove loose fragments of bone or cartilage caused by the dislocation or reduction or to help prevent further dislocation. Elevating the injured knee will also help to reduce swelling. Immobilization by splinting, casting, or bracing without immobilization for up to six weeks. After immobilization stretching and strengthening of the injured stiff and weakened joint and surrounding muscles are necessary.

Valgus Stress Test at 0° and 30°

Although the accuracy of valgus stress testing is not well defined, the gold standard for evaluating the MCL is the valgus stress test performed at 30° of knee flexion with the tibia in external rotation. The valgus stress test in full extension evaluates the PMC and the POL as well as the MCL. The ACL is also an important secondary stabilizer at full extension, but only after the superficial MCL has been compromised. Because most patients with collateral liga- ment injury are treated without surgery, extensive correla- tion of clinical examination findings with arthroscopic data has not been performed. One study documented a valgus stress test sensitivity of 86% in 72 patients with arthro- scopically confirmed MCL tears.43 Some studies have attempted to compare valgus stress testing on clinical examination with magnetic resonance imaging (MRI) find- ings; in general, agreement between the 2 diagnostic meth- ods has appeared to be no better than fair to good.85,113 Recommended Technique. The patient is placed supine with the hip of the affected limb slightly abducted and the knee flexed to 30° over the side of the table. The examiner positions one hand over the lateral aspect of the knee and grasps the ankle with the other hand. A valgus stress is applied. The test is then repeated in full extension.79 Grading the valgus stress test incorporates both the amount of medial joint opening and the quality of the end- point. Grade I is assigned to knees with 5 mm or less of joint opening and a solid endpoint, grade II corresponds to a 6 mm to 10 mm opening with a good endpoint, and grade III represents >10 mm of opening and a soft endpoint.50 At 30° of flexion, the PMC and POL provide relatively little resistance to valgus stress, and the superficial MCL has a much more important role. Accordingly, maximum instability at 30° of flexion with relative stability at 0° signifies an isolated superficial MCL injury, with the severity of injury based on grade. According to Hughston et al,50 a valgus stress test positive in full extension denotes injury to both the MCL and the PCL. In their study, ACL integrity was not seen to affect the valgus stress test in extension. Marshall and Rubin,82 however, suggested that in addition to revealing incompetence of the PCM and MCL, a positive test result in extension indicates laxity of either cruciate ligament or both.

Anterolateral Rotatory Instability (ALRI)

An important secondary function of the ACL is the pre- vention of rotational instability of the knee joint by pre- vention of excessive internal rotation of the tibia relative to the femur. Several clinical tests, including the pivot-shift test, the anterior drawer test with the tibia in neutral rota- tion, and various accessory tests, may be used to assess the presence and degree of ALRI. If all test results are nega- tive, yet ALRI is still suspected, examination under anes- thesia (EUA) may be of value. Anterior cruciate ligament injuries associated with ALRI are not uncommon. Norwood and Cross90 reported that EUA reveals unsuspected ALRI in 18% of patients treated operatively for ACL deficiency. Anterolateral rotatory instability typically results when there is acute internal rotation and varus stress on the weightbearing knee, such as when a basketball player loses his balance while landing from a jump.51 According to Hughston et al,51 injury to the middle one third of the lateral capsular ligament is implicated in this type of instability and may underlie ALRI in cases when the ACL is intact. Symptoms include a perception of instability as the knee approaches extension, and in cases of coexisting meniscal injuries, ALRI must be ruled out before a patient's symp- toms should be ascribed to the meniscal tear alone. Hsieh and Walker47 showed that at 30° of flexion, the axis of internal rotation in the transverse plane is located on the medial side of the knee. Therefore, the secondary structures anatomically most effective at reducing ALRI (internal rotational laxity in the presence of lateral capsu- lar injury) are the ACL and the MCL. The PCL is substan- tially less able to resist anterolateral rotation than the ACL because its insertion is in close proximity to the transverse axis of rotation and because it is more vertically oriented than the ACL.47 Fleming et al32 found that the application of an internal rotation force to the tibia pro- duces an increase in ACL strain, and the additional appli- cation of valgus stress plus internal rotation increases ACL strain values significantly compared with internal rotation in isolation. The highest ACL strain values are found at knee flexion angles of 0° to 30°,32 whereas at flex- ion angles of greater than 30°, ACL strain decreases with the recruitment of secondary stabilizers.60,112 These find- ings are consistent with the observation that clinically sig- nificant anterolateral tibial subluxation in the context of ACL incompetence occurs at flexion angles from 0° to 30°. As above, detection of anterior tibial translation in com- bination with tibial internal rotation by use of the pivot- shift test, the anterior drawer test in neutral rotation, and accessory tests serves as a basis for identifying ALRI. The pivot-shift and anterior drawer tests have been described above. According to Hughston et al,51 when the lateral tib- ial condyle becomes more prominent or both condyles become equally prominent during the anterior drawer test with the tibia in neutral rotation, this is suggestive of ALRI and should be followed by a confirmatory jerk test as described below.

The Quadriceps Active Test

As opposed to passive tests, which rely on externally imposed forces, this test uses the patient's own quadriceps contraction as the displacement force. The test was originally described by Daniel et al20 who reported identifying confirmed PCL dis- ruption in 41 of 42 knees, while pathologic anterior tibial translation did not occur in any patient's contralateral, nor- mal knee, nor in 25 other normal knees, nor in knees with documented ACL disruption. It should be noted that previ- ous injury or surgery altering the native orientation of the patellar ligament may render the quadriceps active test use- less.20 Although it is reported to be highly sensitive and spe- cific in the original description of the test, the quadriceps active test was found by other researchers to be less sensi- tive (54%) compared with other tests for PCL deficiency.98 A second use of this maneuver is to determine the quadri- ceps neutral angle of the patient's normal, contralateral knee—that is, the angle at which a quadriceps contraction produces no apparent tibial shift (usually around 60° to 70° of flexion). At the quadriceps neutral angle, the vector of force generated by the quadriceps is parallel to the tibial shaft, and contraction of the quadriceps at this angle will merely increase joint contact pressure if the foot is pre- vented from moving. By locating the quadriceps neutral angle in the patient's normal knee, deviations from normal may be better understood in the injured knee for detection of both anterior and posterior laxity. Recommended Technique. The patient is placed in the supine position with the knee flexed to 90°. The flexion angle of the knee at which the test is performed is critical and must exceed the quadriceps neutral angle described above. At 90° flexion, the quadriceps force vector angle includes a component of anterior drawer in relation to the shaft of the tibia. Thus, if a patient is asked to attempt to slide their fixed foot anteriorly (inducing a gentle quadri- ceps contraction), a sagged or posteriorly subluxated tibia will move in an anterior direction. This dynamic reduction of the tibia in relation to the femur represents a positive result for PCL deficiency if the tibia shifts anteriorly by at least 2 mm.20

The Posterior Sag Test

As opposed to the posterior drawer, which is a dynamic clinical test, the posterior sag test is a static test. It has been shown to have 100% specificity for detecting PCL injuries. Its sensitivity has been reported at 79% by Rubenstein et al Recommended Technique. The patient is placed supine with knees flexed to 90°. The patient's feet are allowed to rest flat on the examination table, and the patient is encouraged to relax completely, especially relaxing their quadriceps. The affected knee is then viewed from the side. A positive result is when the anterior aspect of the proxi- mal tibia is found to "sag" posterior to the anterior aspect of the femoral condyles or in comparison with the normal, contralateral knee.3,61 The posterior sag test is illustrated in Figure 6.

Relative load reduction and biomechanical correction

As patellar tendinopathy is predominantly a strain-related phenomenon, initial conservative management should involve some form of load reduction to limit progression of the pathology. Given the detrimental effects of complete immobi- lization, load reduction should be achieved by relative rest rather than complete cessation of activity. Relative rest means that the athlete may be able to continue playing or training, if it is possible to reduce the amount of loading through modification of pain-provoking activities and reduction in total training hours. In addition to changing training activities and durations, patellar tendon loading may be reduced through biomechanical correction. Correcting biomechanics of the lower limb kinetic chain can improve its energy-absorbing capacity and redistrib- ute forces from the knee and patellar tendon. Biomechanical correction can be as simple as training how to land so that greater load is absorbed by distal and proximal joints. When landing, the ankle and calf are critical in absorbing the initial load and reducing load being transmitted to the knee [71]. Approximately 40% of landing energy is transmitted proximally, and thus a functioning calf complex is required to absorb the major portion of the initial load [45]. Similarly, functioning of the hip complex is important. When a large range of hip flexion is combined with forefoot landing, vertical ground reaction forces can be further reduced [72]. To assist distal and proximal joints in absorbing more load, correction of anatomical and functional abnormalities may be needed. Inflexibility of the quadriceps, hamstrings, iliotibial band, or calf has the potential to restrict range- of-motion at the knee and ankle, and to increase the load on the patellar tendon. Similarly, weakness of the gluteal, lower abdominal, quadriceps, and calf muscles may lead to fatigue-induced aberrant movement patterns that may alter forces acting on the knee [45]. Forces on the knee may also be influenced by foot mechanics, and thus shoe orthoses may be indicated in some athletes.

VALGUS INSTABILITY

Biomechanical research indicates that in addition to the role of the MCL as a rotational restraint, the anterior fibers of the superficial MCL act as the primary restraint to valgus load.18,111 In at least 1 study, no significant increase in valgus rotation occurred unless the anterior fibers of the superficial MCL fibers were sectioned. Sectioning of the deep MCL and POL resulted in minimal valgus rotation until the superficial fibers of the MCL were completely cut, at which point 7 mm of medial joint line opening occurred along with up to a 300% increase in val- gus rotation.111 In a valgus-restricted model, Grood et al40 showed that the superficial MCL was the primary restraint to valgus stress, responsible for 78% of medial stability at 25° of flexion and 57% at 5° of flexion. Secondary supports against excessive valgus motion are the deep MCL and the POL. Research has shown the POL and the PMC to resist valgus force at 5° of flexion.18 The ACL has also been shown to withstand valgus stress under certain circumstances, such as when the knee approaches full extension in the case of superficial MCL deficiency. In the 5 degrees of freedom model, after the MCL and ACL are sectioned, there are large increases in valgus laxity,54 whereas if freedom of knee motion is not restricted, an applied valgus moment is not resisted solely by the MCL but is in fact shared by other ligaments and joint struc- tures, particularly the ACL, and the ACL is recruited to provide restraint against pathologic valgus instability with as little as 5° of abnormal valgus rotation.5

Posterolateral Rotatory Instability (PLRI)

Description Injury to the Posterolateral corner (PLC) that results in posterior shift of posterolateral tibia. Diagnosis and treatment failure could result in failure of ACL reconstruction. PLC composed of lateral collateral ligament, arcuate ligament complex, fabellofibular ligament, posterolateral capsule, IT band, biceps tendon, and popliteus muscle- tendon complex. Mechanism of Injury force directed posteriorly against the knee with resulting hyperextension Special diagnostic tests Posterior drawer test; Posterior lachman test; Dial test at 30 and 90 degrees; Reverse pivot-shift test; Posterolateral drawer test; External rotation recurvatum test; Posterolateral external rotation test

Posteromedial Rotatory Instability (PMRI)

Description least common form of rotatory instability; injury to the medial capsular ligament, tibial collateral ligament, POL, and ACL causing the proximal medial tibia to sag posteriorly and shift posteromedially when valgus stress is applied. Mechanism of Injury concominant valgus force with hyperextension of the knee Special diagnostic tests apply valgus stress and assess for posterior shift of proximal medial tibia

Varus Instability

Description Injury to the LCL (primary valgus stabilizer) or the PCL (secondary valgus stabilizer) Mechanism of Injury excessive varus force (rarely occurs in isolation) Special diagnostic tests Varus stress test at 0 and 30 degrees

Valgus Instability

Description Injury to the superficial MCL, which acts as the primary restraint to valgus force, as well as injury to ACL, which is the secondary restraint to valgus load. Mechanism of Injury excessive valgus force Special diagnostic tests Valgus stress test at 0 and 30 degrees

Posterior Instability

Description damage of the anterior cruciate ligament (ACL) to the extent that it is no longer able to prevent excessive anterior translation of the tibia relative to the femur. Mechanism of Injury abrupt deceleration; hyperextension; pivot on a fixed foot; blow to lateral aspect of the knee when foot is planted Special diagnostic tests Posterior drawer test (most sensitive); Posterior lachman test; Posterior sag test; Quadriceps active test;

Anterolateral Rotatory Instability (ALRI)

Description damage to the middle one third of the lateral capsular ligament and/or ACL. The secondary role of the ACL is to limit excessive internal rotation of the knee and it is not uncommon for ACL injuries to be associated with ALRI. Mechanism of Injury acute internal rotation and varus stress on the weight bearing knee (ex: when basketball player loses his balance while landing from a jump) Special diagnostic tests Pivot-shift test; Anterior drawer test; Jerk test; Losee test; Side-lying test of Slocum; Flexion rotation drawer test

Anteromedial Rotatory Instability (AMRI)

Description excessive valgus motion coupled with external rotation of the knee that occurs when the anteromedial tibial pateau subluxates anterior to the corresponding femoral condyle. The posteromedial corner (PMC) provides restraint to this range of motion (made up of 5 structures: posterior horn of medial meniscus, posterior oblique ligament, semimembranosus expansion, meniscotibial ligaments, oblique popliteal ligament). Mechanism of Injury abrupt external rotation/abduction force (ex: clipping injury in American football) Special diagnostic tests Slocum test (based on premise that PMC is secondary restraint to anterior translation when ACL is deficient

Anterior Instability

Description damage of the anterior cruciate ligament (ACL) to the extent that it is no longer able to prevent excessive anterior translation of the tibia relative to the femur. Mechanism of Injury abrupt deceleration; hyperextension; pivot on a fixed foot; blow to lateral aspect of the knee when foot is planted Special diagnostic tests Lachman test; Anterior drawer test; KT-1000 and KT-2000 Arthrometry; Pivot-shift test

SUMMARY AND CONCLUSIONS

In summary, the load sharing between knee ligaments is complex. Frontal plane ''valgus collapse'', as well as sagittal and transverse plane biomechanical factors, likely contribute to ACL injury events. Non-contact ACL injuries almost certainly occur during complex, multiplanar knee joint load states during multiplanar sports movements, rather than during single sagittal planar mechanisms of injury. Although studies indicate that sagittal plane biomechanical factors are probably a part of the ACL loading mechanism, it is highly doubtful that these injuries occur solely as a result of sagittal plane loading mechanisms, especially in the female athlete. Prevention programmes that solely target high-risk sagittal plane landing mechanics fail to address the important frontal and transverse plane contributions to ACL injury mechanisms. Multiplanar training exercises that focus on lowering risky biomechanics in multiple planes such as large knee valgus, internal/external knee rotations and shallow knee flexion angles are needed to minimise hazardous knee loading conditions that cause ACL injury.

Lubowitz JH, Bernardini BJ, Reid JB. Comprehensive physical examination for instability of the knee. Am J of Sports Med 2008; 36:577-594.

In the treatment of knee instability, it is imperative that clinicians make accurate diagnosis in order to provide specific and effective treatment. Due to the fact that many knee injuries can involve more than one structure one must conduct a comprehensive examination of the knee. In addition to special tests to detect specific instabilities of the knee it is important to pay attention to direction of instability, mechanism of injury, and symptomatology to make a comprehensive clinical decision. Various knee instabilities will be described below as well as special tests listed to assess for each type of instability.

Meniscal Transplant:

Indications prior total meniscectomy knee joint arthrosis (less than 2 mm of tibiofemoral joint space) age 50 or less flattening of femoral condyle pain in the involved tibiofemoral compartment or articular cartilage degeneration concavity of the tibial plateau 2 mm or more of tibiofemoral joint space Contraindications osteophytes, knee joint instability knee arthrofibrosis muscular atrophy prior joint infection

Meniscal Repair:

Indications at least 8 mm of intact meniscal tissue without fragmentation tears located in the inner one-third region (rim width greater than 8mm) under age 50 or in 50's and athletic Contraindications tears with major tissue fragmentation tears with edges that cannot be reduced longitudinal tears less than 10 mm in length incomplete radial tears

What is the management of plica

Initial treatment consists of medications and ice to relieve pain and reduce inflammation, stretching and strengthening exercises (of the hamstrings and quadriceps), and modification of the activity that produces the symptoms. A cortisone injection may be recommended to reduce the inflammation of the plica. Arch supports may also be recommended. Otherwise, surgery is indicated in cases that do not respond to conservative treatment.

what is the management of meniscus tear

Initially treatment should consist of ice and medication to reduce swelling and control pain. Range of motion, stretching, and strengthening exercises are performed. Surgery is often recommended as a definitive treatment and is performed arthroscopically. Usually the tear is removed partly or completely.

Reinold MM. Solving the patellofemoral mystery. 2010; 1-35. patellofemoral

It is also important to understand patellofemoral joint contact area and joint reaction forces. The greatest amount of patellofemoral compression is created by the most minimal contact and greatest hamstring force. For OKC exercises, the greatest force is in full extension, therefore, exercises should be performed between 50-90 degrees flexion generally. Likewise, for CKC exercises the greatest force is in flexion, therefore, exercises should be performed between 0-50 degrees generally.

Apprehension Test

Manual translation maneuvers are also used in the apprehen- sion test, first described in 1936 by Fairbank29 as a means of evaluating patellar dislocation. In a positive test result, as pas- sive lateral patellar translation commences as described in the manual translation test above, the patient becomes visibly uncomfortable and apprehensive, begins to resist patellar sub- luxation with quadriceps muscle tension, and attempts to flex the knee and pull the patella back into a reduced position.49,79 Recommended Technique. The patient is placed in the supine position, and the quadriceps is relaxed. The knee is fully extended (although Fairbank described that the test should be performed in 30° of knee flexion). The examiner places both thumbs on the medial border of the patella and slowly and gently attempts to displace the patella laterally. The patient's reaction is noted. No pain is normal, but pain during the maneuver, while notable, does not represent a positive test finding. Rather, frank patient apprehension, or patient expression of fear that the patella will dislocate, represents a positive test result.

Massage

Massage therapy is used in patellar tendinopathy to promote repair and to decrease adhesions between the tendon fibers [29]. Research in healing rodent tendons showed soft-tissue mobilization to increase fibroblast recruitment and promote healing [94,95]. Clinically, in tendinopathy the most effective form of massage appears to be digital ischemic pressure followed by deep transverse friction throughout the entire tendon. Massage should also be performed on both the calf and quadriceps muscles to maintain their compliance [29,45]. This may take the form of sustained myofascial tension.

The Lachman Test

Named for his mentor, John W. Lachman, MD, chairman and professor of orthopedic surgery at Temple University, this clinical test was originally described by Joseph S. Torg, MD.106 When the test was first discussed, the recommenda- tion was for the examiner to hold the knee "between full extension and 15° of flexion." Now, however, it is common to place the knee in 30° of flexion. One must ensure that the tibia is not subluxated posteriorly to avoid a false-positive test result and misdiagnosis of ACL insufficiency in a poste- rior cruciate ligament (PCL)-deficient knee. The tibia must rest in neutral rotation because internal or external rotation will recruit secondary stabilizers, thereby confounding assessment of the ACL.80 The Lachman test offers high sensitivity and high specificity (approaching 95%).62 False- negative results have been attributed to concomitant bucket-handle meniscal tears that interfere with anterior tibial translation106 or scarring of a torn ACL to the PCL, although some data indicate that additional meniscal or lig- amentous injuries generally do not alter test sensitivity.23 Recommended Technique. With the patient supine and the knee positioned in 30° of flexion, the examiner stabi- lizes the anterolateral distal femur with one hand and uses the other hand to exert firm pressure on the posterior aspect of the proximal tibia in an attempt to induce anterior dis- placement. Proprioceptive and/or visible anterior translation of the tibia beyond the femur with a "mushy" or "soft" end- point represents a positive test result.106 Qualitative and quantitative measures describe the results of the test, gener- ally in comparison with the contralateral normal knee. Anterior translation of 1 mm to 5 mm is defined as grade I axity, 6 mm to 10 mm as grade II, and >10 mm as grade III. The quality of the endpoint is also graded as firm, soft, or absent. Here, and below, this grading system and these qualities are relative to a normal, contralateral knee. Difficulty performing the test in situations where clini- cian's hands are small relative to the patient's thigh girth can be a limitation of the Lachman test.24-26 In such cases, a variation on the Lachman test has been described in which the examiner cradles the patient's leg in the axilla and places his hands behind the tibia. While pushing the tibia anterior, the examiner attempts to discern excessive anterior displacement of the tibia while observing any reduction in the contour of the patella and its tendon.71 The sensitivity of this alternative has not been well described.79 The Lachman test is illustrated in Figure 1 (all figures illustrate the right knee).

Typical postures at the time of ACL injury

Non-contact ACL injuries often exhibit a common body posture that involves a valgus collapse of the knee joint, with the knee near full extension (between 0u and 30u), external tibial rotation with the foot planted during a deceleration manoeuvre.9 11 Video studies by Olsen et al21 and Krosshaug et al9 found that dynamic valgus collapse was the most common ACL injury mechanism for female handball and basketball athletes. Krosshaug et al9 also found that female basketball players demonstrated a 5.3 times higher relative risk of valgus collapse during ACL injury compared with male basketball players. Female athletes exhibit more knee valgus motion and torque during athletic movements than men and these altered mechanics are predictors of future ACL injury risk.20 29-32 We prospectively screened athletes before their athletic seasons and discovered that during landing, athletes who went on to experience ACL injury had knee valgus angles more than 8u greater than athletes who completed the season uninjured. Our preseason measure of dynamic valgus moments predicted ACL injury with 73% sensitivity and 78% specificity.20 It is conceivable that men and women have different primary underlying mechanisms of ACL injury, with women experien- cing more injuries as a result of valgus collapse than men (figs 1 and 2). Over 50% of the women in a Norwegian handball study demonstrated a valgus knee collapse during the injury event, whereas only 20% of the men showed a similar collapse.9 A recent study by Boden et al10 corroborated these findings, showing that women had higher valgus angles than their male counterparts during ACL injury.10 Mathematical modelling studies demonstrate that perturbations to the lower extremity during a side-step cutting manoeuvre can lead to external valgus loads that are capable of rupturing the ACL and these valgus loads occur more frequently in women than men.33

Dial Test at 30° and 90° (Prone External Rotation Test)

Originally described by Cooper et al15 in 1991, this test assesses abnormal external tibial rotation and also helps differentiate between isolated PLC injury and combination PLC/PCL injury. Recommended Technique. Although this test can be per- formed with the patient prone, supine, or sitting, the authors15 recommend the prone position. The patient's knees are initially flexed to 30°. The examiner places both hands on the feet of the patient, cupping the heels and placing the fin- gers and thumb along either side of the talar-calcaneal bony contours. A maximal external rotation force is applied by the examiner, and the foot-thigh angle is measured and compared with the contralateral side. The knees are then flexed to 90°, and again an external rotation force is applied and the foot- thigh angle is measured. During application of the external rotation force, it may be useful to palpate the tibial condyles to determine their position in relation to the femoral condyles before measuring the foot-thigh angle. When comparing the degree of limb external rotation, a difference of 10° or more is significant. Posterolateral subluxation of the lateral tibial plateau indicates PLRI; anteromedial subluxation of the medial tibial plateau is consistent with AMRI as noted in the sec- tion describing AMRI above. Once PLRI is confirmed and foot-thigh measurements have been taken, results of the test are interpreted. An isolated PLC injury is diagnosed if there is greater than 10° of external rotation versus the contralateral side at 30° of flexion but not at 90°. An impor- tant point is that, in this scenario, the external rotation of the involved knee actually diminishes when it is flexed to 90° because of restraint in the context of an intact PCL. In contrast, greater than 10° of increased external rotation in the affected knee at both 30° and 90° suggests a combina- tion PLC and PCL injury.14,15,39,41,73,108-110 The dial test is illustrated in Figure 12.

External Rotation Recurvatum Test

Originally described by Hughston et al50,52 as the ultimate diagnostic test for PLRI, the external rotation recurvatum test has also been noted to be difficult to interpret. Thus, other tests, such as the posterior and posterolateral drawer tests, should be performed to obtain additional diagnostic evidence. Recommended Technique. Traditionally, the patient is placed supine on the examination table with his or her legs together. With the patient's knees in extension, the great toes of both feet are then grasped to lift the legs off the table. A positive result is when the knee falls into varus, hyperextension, and external rotation when compared with the uninvolved side. This finding was originally thought to indicate injury to the PLC; however, excessive varus and hyperextension during the test may indicate combined PLC plus ACL or PCL injury.109 A variation on the external rotation recurvatum test requires the examiner to hold the heel of the affected limb while extending the knee from 30° of flexion to full exten- sion. The examiner's other hand grasps the posterolateral aspect of the knee to assess relative hyperextension and external rotation compared with the uninvolved side. According to Veltri and Warren,110 this test result may be mildly positive in the varus knee with isolated PLC injury; again, when there is substantial varus and hyperexten- sion, ACL or PCL injury is also likely. The external rotation recurvatum test is illustrated in Figure 15.

Osgood-Schlatter disease o Pathology and MOI

Osgood-schlatter disease results from stress or injury to the tibial tubercle growth plate (which is still developing during adolescence), causing a flare-up. Repeated stress or injury interferes with development, causing inflammation.

Patellar subluxation/dislocation o Pathology and MOI

Patellar subluxation or dislocation is caused by a direct blow to the knee, twisting or pivoting such as with cutting, a powerful muscle contraction or because of a congenital abnormality such as a shallow or malformed joint surface.

Summary

Patellar tendinopathy is a common and serious condition in athletes. Although there have been many advances in the understanding of the histopathology, imaging, and surgical outcomes in this condition in the past decade, successful management of athletes with patellar tendinopathy remains a major challenge for both the practitioner and patient. There is a definite need for further prospective studies into etiological factors and randomized controlled trials into treatment choices.

Patellofemoral Joint Pain Syndrome o Pathology and MOI

Patellofemoral pain syndrome is the most common cause of knee pain in the outpatient setting. It is caused by imbalances in the forces controlling patellar tracking during knee flexion and extension, particularly with overloading of the joint. Risk factors include overuse, trauma, muscle dysfunction, tight lateral restraints, patellar hypermobility, and poor quadriceps flexibility.

Plica Inflammation o Pathology and MOI

Plica is caused by trauma to the knee, either direct or with repetitive knee bending and straightening activity, causes thickening of the plica and it loses its elasticity. As a result the plica pinches on the inner knee joint and inner patella. The pain is felt to be due to pinching or pulling of the plica band, which has many nerve endings.

What are the signs and symptoms of patella dislocation

Signs and symptoms Severe pain when attempting to move the knee and a feeling of the knee giving way Tenderness, swelling and bruising of the knee Numbness or paralysis below the dislocation from pinching, cutting, or pressure on the blood vessels or nerves (uncommon) Deformity Often relocates on its own when knee is straightened Lump on the inner knee

Anteromedial Rotatory Instability (AMRI)

Slocum et al104 described excessive valgus motion coupled with external rotation of the knee as AMRI. This occurs when the anteromedial tibial plateau subluxates anterior to the corresponding femoral condyle. The posteromedial corner (PMC) has been shown to serve as a restraint to AMRI throughout the normal range of motion. The PMC is func- tionally composed of 5 anatomic structures: the posterior horn of the medial meniscus, the posterior oblique ligament POL), the semimembranosus expansions, the meniscotibial (coronary) ligaments, and the oblique popliteal ligament.102 Anteromedial rotatory instability typically results from an abrupt external rotation-abduction force, such as occurs dur- ing a "clipping" injury in American football. Anteromedial rotatory instability may represent the most common form of knee instability in addition to the most frequent cause of ACL disruption; however, disability associated with AMRI may, at first, be minimal. Over time, this type of instability often pro- gresses to associated anterolateral rotatory instability (ALRI), and when AMRI is combined with ALRI, the func- tional disability may be significantly more incapacitating

The Side-Lying Test of Slocum

Slocum was the first to suggest the term ALRI and devel- oped a version of the pivot-shift test as a means of ascer- taining this disorder.103 The side-lying test of Slocum may be especially useful in the acute setting and whenever a patient has hamstring spasm or guarding or when a patient's leg is too heavy to easily manipulate. Recommended Technique. The patient is placed in the lat- eral decubitus position with the effected side up, the pelvis in 30° of ipsilateral external rotation, and the knee in question fully extended. The medial aspect of the affected foot is placed on the examination table, permitting the affected knee to sag into varus. With the knee in this position, the tibia rotates internally, tension is applied to the MCL and medial capsule, and the lateral tibial plateau and lateral femoral condyle are compressed. This position minimizes the restricting effects of muscle tension, yet some authors recommend slight knee flexion (approximately 10°) so as to remove other stabilizing influences, such as that provided by tension of the PCL and posterior capsule as well as the bony architecture of the knee. Anterior subluxation of the lateral tibia may be appreciated at the joint line. The exam- iner then places both hands on the leg with the thumbs pos- terior and the fingers anterior and applies an anterior drawer while flexing the knee. A positive test result consists of audible and/or palpable reduction occurring as the knee is flexed and as the ITB changes from a knee extensor to a knee flexor between 25° and 45°.

Surgical treatment

Surgery for patellar tendinopathy is only indicated after a prolonged (6 months) and well-supervised conservative treatment program fails. Surgery may involve excision of degenerated areas, arthroscopic debridement, repair of macroscopic defects, multiple longitudinal tenotomies, drilling of the inferior pole of the patella, resection of the tibial attachment of the patellar tendon with realignment, percu- taneous needling, or percutaneous longitudinal tenotomy [29,41]. As the patho- physiology of patellar tendinopathy is not known, the exact surgical technique chosen is based on the surgeon's opinion and experience [29]. There is no consensus as to the optimal surgical technique to use. Surgery is not indicated in the initial management of patellar tendinopathy, as surgical outcomes are rather unpredictable and recovery can be extended. A review of 23 papers found that the outcome following surgery was either excellent or good in 46% to 100% of cases, with an overall success rate of 75% to 85% being a very- best-case estimate [96]. Thus, 15% to 25% of patients will experience persistent or recurrent tendon pain following surgery. The recovery following surgery, even with a good or excellent result, can take 6 to 12 months [40,57], and many athletes will not be able to return to their previous level of sport [97]. Consequently, surgery should only be considered after a thorough, high-quality, conservative manage- ment program has been attempted.

Q-Angle Assessment

The Q-angle refers to the angle created by a line drawn from the anterior superior iliac spine (ASIS) to the center of the patella and from the center of the patella to the tib- ial tuberosity. A normal Q-angle is up to 15° in women and 10° in men. Greater angles increase laterally directed forces on the patella through the pull of the patellar ten- don. The Q-angle is typically measured on the supine patient whose hips and knees are in neutral position.9,84 A Q-angle should also be assessed with the patient in a sit- ting position with knees flexed at 90°. If the Q-angle is measured in extension, the examiner must first reduce the patella in the trochlear groove. A laterally subluxated patella will result in measurement of a falsely low Q-angle. Especially in patients with rotationally lax knees, an apparently normal Q-angle in the supine position and knee extension may be abnormal in a more functional position of knee flexion with external rotation applied to the tibia.66 Furthermore, at 90° of flexion, the patella is engaged and centered in the trochlear groove,95 minimizing risk of a falsely low Q-angle measurement. Recommended Technique. With the patient supine, the examiner marks the center of the tibial tuberosity. Next, while the patient relaxes, the examiner centers the patella in the trochlear groove and marks the center of the reduced patella. Finally, the examiner locates the ASIS and places the patient's extended index finger as a marker of the ASIS. A goniometer is used to measure the angle rom the ASIS to the center of the reduced patella to the center of the tibial tuberosity.

The Slocum Test

The Slocum test104 is based on the premise that the PMC is a secondary stabilizer against anterior translation in the flexed ACL-deficient knee when the tibia is externally rotated. Thus a positive test result is represented by fail- ure of tibial external rotation to diminish the anterior drawer in an ACL-deficient knee. A differential diagnosis for AMRI is posterolateral rotatory instability (PLRI) and vice versa. Posterolateral rotatory instability is diagnosed using the dial test (described in detail below). When a diag- nosis of AMRI or PLRI is suggested based on the Slocum or dial test results, respectively, the examiner must carefully determine whether the anteromedial tibia is rotating ante- riorly relative to the medial femoral condyle (AMRI) ver- sus whether the posterolateral tibia lateral is rotating posteriorly relative to the lateral femoral condyle (PLRI). This is reviewed in the discussion of PLRI. Recommended Technique. To evaluate the knee for AMRI, the anterior drawer test is performed as described above. Increased anterior translation of the tibia relative to the femur will be noted in an ACL-deficient knee. Next, the test is repeated with the foot fixed in approximately 15° of exter- nal rotation, tightening the PMC, and secondarily reducing the positive anterior drawer. Absence of this reduction of anterior translation during external rotation as a result of PMC deficiency is a positive test finding for AMRI. As some degree of physiologic anteromedial rotation is to be expected and the normal tissue laxity may vary, compari- son with the uninjured contralateral knee is required.71

What is the management of HO

The developing consensus appears to be that aggressive PROM and continued mobilization, once acute inflammatory signs have subsided, are indicated, because they help to maintain ROM and (in more extensive HO) they may lead to the formation of a pseudarthrosis. Resting the joint appears more likely to lead to decreased ROM or to ankylosis.

What is the optimal timing for surgery for an anterior cruciate ligament injury? Level 2

The increase in time between the injury and reconstruction of the ACL is a risk factor for meniscal and cartilage damage (Church and Keating 2005, Foster et al. 2005, Kim et al. 2005, Vasara et al. 2005. Seon et al. 2006, Ohly et al. 2007, Papa- gasteriou et al. 2007, Granan et al. 2009, Tayton et al. 2009 Vasara et al. 2005).

Manual Translation Test

The manual translation test evaluates lateral patellar mobility. Reversal of this maneuver can be used to assess medial patellar displacement. Carson et al9 believe that the patella should not displace in either direction more than one half the width of the patella. Others have described a grading scheme for patellar translation in which the width of the patella is divided into quadrants. Lateral displacement of no more than 2 quadrants is within normal limits. Lateral displacement of 3 quadrants suggests an incompetent medial restraint, and lateral dis- placement of 4 quadrants indicates a patella that can be dislocated. Medial displacement of 1 quadrant indicates a tight lateral retinaculum and usually correlates with decreased patellar tilt, whereas medial displacement of greater than 3 quadrants suggests a more global laxity of the soft-tissue restraints of the patella.66 Recommended Technique. The patient is placed in the supine position, and the quadriceps is relaxed. The knee is fully extended (although some prefer to perform the examina- tion with the knee in mild flexion). The examiner places both thumbs on the medial border of the patella and slowly and gently attempts to displace the patella laterally. Translation is measured and recorded as the number of quadrants of patel- lar subluxation attained. The test is then repeated in the oppo- site direction to assess medial patellar translation.

Patellar tendonitis o Pathology and MOI

The most common causes of patellar tendonitis are a rapid increase in the frequency of training, a sudden increase in the intensity of training, a transition from one training method to another, repeated training on a rigid surface, improper mechanics during training, genetic abnormalities of the knee joint, and/or a poor base strength of the quadriceps muscles.

The Anterior Drawer Test

The origins of the anterior drawer test are obscure,106 although before the introduction of the Lachman test, the anterior drawer was the usual clinical examination for diagnosis of an ACL tear. Despite its historical importance, many authors have questioned its reliability and validity in the diagnosis of ACL injury.106 The posterior meniscal horns or the bony contour of the joint may interfere with the test. Additional limitations of the anterior drawer test are the impracticality of requiring 90° of flexion in an acutely injured or swollen knee, hamstring spasm that may restrict anterior translation at 90°, and secondary sta bilization against anterior translation of the knee at 90° flexion by the MCL.101 Whereas test accuracy may improve in patients with chronic injury or loss of secondary restraints to anterior displacement, sensitivity in an alert patient is variably reported from 22% to 95%, although it is reported to improve to between 50% and 95% in the anesthetized patient.23,43,5 Recommended Technique. The patient is placed in a supine position with the knee flexed to 90° and the tibia in neutral rotation. The femoral condyles should normally be palpable 1 cm posterior relative to the anteromedial tibial plateau, and this relationship should be confirmed before performing the anterior drawer test to avoid misdiagnosis in a PCL-deficient knee.34,79 The patient must be encouraged to relax the hamstring muscles fully so as to minimize ham- string dynamic resistance to anterior tibial translation. When the patient is sufficiently relaxed, the examiner grasps the proximal tibia with both hands while placing both thumbs along the anterior joint line. A positive test result is indicated by increased anterior translation and a soft endpoint and graded similar to the Lachman test. The anterior drawer test is illustrated in Figure 2.

Varus Stress Test at 0° and 30°

The origins of using the varus stress test to detect LCL laxity are unclear. "Abduction and adduction rocking" of the knee as a means of examining collateral ligament integrity appears to be the antecedent of the current test.96 The varus stress test has undergone little assessment of sensitivity and specificity, although a small study suggested that in an emergency room setting, there may be fairly poor correlation between clinical examination and arthroscopic findings.43 Recommended Technique. The patient is placed in the supine position with the tibia held in gentle internal rota- tion. The examiner places one hand on the medial aspect of the thigh and the other on the proximal tibia. The involved knee is flexed to 30°, and a varus force is applied across the joint line. The test is then repeated at full extension.69 The test finding is positive when the lateral joint line can be opened to a greater degree than the uninvolved side. The conventional grading system is based on the amount of lat- eral joint line opening compared with the contralateral joint. Grade I correlates with a lateral opening of 0 to 5 mm greater than the contralateral side, grade II is represented by an increased opening of 6 mm to 10 mm, and grade III is an opening of >10 mm versus the uninvolved side. Other grading systems have since evolved, including those of Tria, Hughston, and O'Donohue.13 Tria believes that dur- ing testing, the examiner should record both the amount of opening in millimeters and the quality of the endpoint. In the Tria grading system, grade I corresponds to a stress test that allows minimal increased opening with varus stress, but the patient may experience pain with the test, usually at the site of the tear in the collateral ligament. Some opening of the joint line, with a distinct endpoint, yields a grade II score, whereas a grade III tear has no distinct endpoint to applied stress, and the knee opens to an almost unlimited degree. Hughston's grading system scores a normal knee as grade 0, an increase in joint opening of 1 mm to 4 mm as grade I, an increase of 5 mm to 9 mm as grade II, and an increase in 10 mm to 15 mm as grade III. Point tenderness has been shown to identify the location of the tear in 78% of cases and local- ized edema in 67%. The O'Donohue grading system contextu- alizes positive test results using the degree of sprain assumed to be present. A mild sprain consists of few torn fibers with no loss of ligament integrity. A moderate sprain corresponds to incomplete tears with no pathologic laxity, and severe sprains have loss of integrity with a mushy or indefinite endpoint. Certain anatomic correlates have been established with regard to positive test findings. When there is pathologic lateral joint line opening at both 0° and 30°, with the maxi- mum at 30°, this indicates an injury to the LCL and the PCL, particularly the arcuate ligament. A combination injury to the LCL and PLC, the PCL, and perhaps also the ACL is suspected when there is significant lateral opening at 0°.10,69,110

Assessment of Patellar Tracking and the J-Sign

The patella is engaged in the trochlear groove in knee flexion. Thus, during active flexion, the patella may be observed to engage the femoral trochlea (reduce) smoothly at approxi- mately 30° to 40° of flexion. Delayed trochlear engagement or abrupt shifts of the patella (out of the trochlea on knee exten- sion or into the trochlea with knee flexion) correspond to a positive J-sign representing a J-shaped path of the patella rel- ative to the trochlea. The patella and tibia show translation, rotation, and excursion within established ranges. Normal patellar translation ranges from 17 mm laterally to 4 mm medially.6,9,29 The J-sign suggests excessive lateral patellar tracking due to unbalanced and excessive lateral forces acting on the patella. Such pathologic changes may predispose the patella to subluxation or dislocation. Recommended Technique. With the patient in a sitting position, the examiner simply observes patellar motion as the patient extends the leg from 90° of knee flexion to full extension or cyclically straightens and bends the knee. Abrupt or extreme lateral shift of the patella represents a positive J-sign.

Reverse Pivot-Shift Test

The patient's perception of the knee suddenly "giving out" may occur in the case of PLRI and in ALRI as the tibia shifts posteriorly on the femur. This is the "reverse pivot shift."55 Recommended Technique. The patient is placed in the supine position with the knee flexed to 90° and the tibia in maximal external rotation. The examiner places a hand on the proximal lateral tibia, applying valgus stress while maintaining external tibial rotation. An axial load is also applied. The examiner's other hand is placed just distal to the first on the anteromedial tibia at midshaft so as to gain full control of the distal leg. The examiner then begins to extend the knee while maintaining external rotation, axial load, and valgus force on the tibia. In a patient with PLRI, the lateral tibial plateau will be posteriorly subluxated at the onset of the test. As the knee is passively extended by the examiner, the lateral tibial plateau will reduce with a palpable shift or jerk when the knee is extended to about 30°. This occurs as the pull of the ITB changes from a flexion vector to an extension vector, thereby reducing the rotatory subluxation through its pull on the Gerdy tubercle.55 The examiner should be alert to the potential for false- positive results. Generalized ligamentous laxity and mild varus alignment have been shown to yield positive test results in normal subjects. Furthermore, the test findings may be pos- itive in up to 30% of normal knees, especially under anesthe- sia. A positive test finding is only considered to be clinically significant when there is a history of trauma, when the reduc- tion phenomenon reproduces the patient's symptoms, and when the finding is present only in the affected knee.

ANTERIOR INSTABILITY

The well-recognized primary function of the anterior cruci- ate ligament (ACL) is to prevent excessive anterior trans- lation of the tibia relative to the femur. Anterior cruciate ligament rupture is epidemic, and as such, a brief consid- eration of ACL injury biomechanics is merited. The mechanism of injury of the majority of ACL rup- tures is not related to contact but typically involves abrupt deceleration, hyperextension, or pivot on a fixed foot.5,93 For contact injuries, the typical mechanism of injury is a blow to the lateral aspect of the knee when the foot is planted and is often associated with medial instability or anteromedial rotatory instability. Patients sometimes report feeling or hearing a "pop," are generally unable to continue sporting activity, and often develop an acute hemarthrosis.18 With chronic ACL insufficiency, the knee is frequently perceived to be unstable, and patients may have activity-related pain or swelling, difficulty walking down- hill or on ice, and trouble coming to a quick stop.75,93 Abnormal anterior tibial translation is the basis for clin- ical diagnosis of an ACL-deficient knee using the Lachman and anterior drawer tests and KT-1000 or KT-2000 arthrometer (MEDmetric, San Diego, Calif). Butler et al8 used cadaveric specimens to demonstrate that the ACL is the primary restraint to anterior translation of the tibia, and the ligament's greatest contribution occurs at 30° of knee flex- ion. Specifically, the ACL was shown to provide an average restraint of 87.2% to an applied anterior load at 30° flexion and 85.1% at 90°. In addition, Beynnon et al4 established in vivo that the ACL experiences greater strain in response to an anterior load at 30° than at 90°. When the ACL is sectioned, the greatest anterior translation (mean value, 8.4 ± 1.9 mm) occurs at 30°. Secondary sectioning of the medial collateral ligament (MCL) increases anterior translation at 90°, but not at 30°, suggesting that the Lachman test at 30° (described below) carries diagnostic specificity for ACL deficiency.42 In vitro and in vivo analyses thus indicate that the Lachman test is the clinical examination of choice for detec- tion of ACL insufficiency and that the Lachman test places more strain on the ACL than the anterior drawer test (also described). Note that both tests, especially the anterior drawer, may be of less value in the acutely injured knee as a result of hemarthrosis and patient pain and guarding. After acute ACL rupture, DeHaven21 found that the Lachman test result was positive (increased side-to-side laxity plus soft endpoint) in only 80% of patients examined without anes- thesia but in almost 100% of patients examined under anes- thesia. The anterior drawer test finding was positive in only 10% of patients without anesthesia and 50% of patients under anesthesia. Both tests have a higher diagnostic value (approaching 97%) in chronically injured patients.2

ACL INJURY PREVENTION PROGRAMMES

There is increasing evidence that neuromuscular training programmes can reduce the risk of ACL injury.8 These programmes have included plyometric, biomechanical analysis and technique feedback, proprioceptive/balance and strength training in various combinations.2 92-94 However, which types of interventions and which biomechanical risk factors should be targeted to reduce ACL injury risk most effectively remains a topic of debate. Prevention and intervention programmes that only target high-risk sagittal plane biomechanics such as shallow knee flexion angles, large distal tibia posterior ground reaction forces and large quadriceps muscle forces may not address other underlying risk factors in the frontal and transverse planes.95 96 Failing to incorporate rotational, multi- directional training exercises during training programmes may hamper ACL injury prevention efforts. We hypothesise that non-contact ACL injury results from multiplanar knee joint loading during three-dimensional sports movements, encompassed by more than simply anterior shear. The load sharing between knee ligaments is complex and it seems plausible that anterior tibial shear force and axial rotation torque also contribute to the resultant ACL loading during the ''valgus'' collapse of the knee so often observed during injury, especially in female athletes.

The Jerk Test of Hughston

This maneuver is a variation on the pivot-shift test and may be considered its opposite. It has been described as the most specific test for ALRI by its eponymous author.51 Recommended Technique. The patient is placed supine with the affected knee in 90° of flexion and the tibia in mod- erate internal rotation. Valgus stress is applied to the knee, and the joint is slowly extended. In a positive test result, the tibia will be maximally displaced anteriorly and internally at approximately 30°, and the examiner will feel a sudden "jerk." Continued extension of the limb will somewhat reduce the anterolateral tibial subluxation, although anterior sub- luxation will persist in the ACL-deficient knee. A torn meniscus may generate a false-positive finding if the meniscus distracts the femorotibial joint through its interpo- sition between the joint surfaces.51 Alternatively, the jerk that occurs during subluxation of the lateral tibial plateau and is sometimes associated with medial joint pain may be misin- terpreted as a medial meniscal tear with an ensuing inappro- priate intervention. Some critics believe that the jerk test may produce a substantial number of false-positive results76 because when a patient's foot is internally rotated at the start of the test, there may be physiological anterolateral tibia sub- luxation. Next, when subsequent application of valgus stress compresses the lateral compartment, this compression may cause a sense of reduction obvious to the examiner and the patient even when ALRI does not exist. The jerk test is illus- trated in Figure 8.

Posterolateral Drawer Test

This test was originally described by Hughston and Norwood in 1980.52 Recommended Technique. The posterolateral drawer test essentially comprises the first stage of the reverse pivot- shift test. The patient is positioned supine with the hip flexed to 45° and the knee flexed to 90°, with the tibia placed in 15° of external rotation. The foot position is then fixed, and a posterior drawer test (described above) is per- formed with the examiner's hands placed along the antero- medial and anterolateral joint line. In its original description, a positive test result consisted of palpation of the lateral tibial plateau externally rotating in relation to the lateral femoral condyle; this finding was believed to be consistent with PLC injury. However, a grossly positive finding of increased external rotation that ensues with posterior tibial force application is more likely indicative of a combined PLC and PCL injury, as has been substantiated by biomechanical evaluation.39,50 False-negative findings may occur. In a combined PLC and PCL injury, the posterolateral drawer sign will be sub- tler and difficult to appreciate.71 In contrast, when the PLC is deficient and the PCL is intact, the medial compartment becomes the new center of joint rotation causing external rotation during the test

The Flexion Rotation Drawer Test

This test was originally described by Noyes et al,91 who suggested that it had the potential to detect ALRI in cases where a pivot-shift phenomenon has yet to develop. This test may also be easier to perform than other tibial trans- lation tests. The flexion rotation drawer test builds on the Lachman test in that femoral rotation as well as tibial translation are observed. Recommended Technique. The patient relaxes in the supine position, with the examiner holding the affected tibia in neutral rotation at 15° of knee flexion using one hand. In the ACL-deficient knee, the femur drops posteri- orly and rotates externally. As the examiner flexes the knee using his other hand, reduction of the tibia with an internal rotation of the femur is appreciated as the knee approaches 40° flexion. Ranging the knee through gentle flexion and extension enables the examiner to note sub- luxation and rotation.

The Losee Test

This test was originally described in 1978 by Losee et al (who believed that this eponymous maneuver was more reliable than the jerk test).76 Dr Ronald Losee shared Hughston's concern that beginning tests for ALRI with the knee in extension creates impingement between the lat- eral femoral condyle and the posterolateral tibia plateau, inducing pain, guarding, hamstring spasm, and damage to the lateral femoral condyle. Recommended Technique. The Losee test begins with the knee held at 45° of flexion and the tibia in external rotation. This ensures that the knee begins in a reduced position. External rotation also accentuates the clunk, which repre- sents a positive test result. The knee is slowly extended while valgus force is applied. The valgus stress is a key com- ponent of this maneuver because it applies a compressive load to the lateral compartment, which also accentuates a clunking subluxation episode. The leg and foot are allowed to drift into internal rotation. In a positive test finding, when the knee reaches approximately 20° of flexion, the lateral tibial plateau shifts anteriorly, which will be per- ceived by the examiner and should also be recognized by the patient as a typical episode of joint instability.

Are studies of non-weightbearing ACL strain and isolated bundles relevant?

Yu and Garrett18 suggested that in-vivo arthroscopic ACL strain measurements indicate that passive valgus torques or external tibial rotations do not significantly increase strains in the ACL.50 However, weightbearing conditions can significantly increase the ACL strain (2-4%) during external tibial torques in the range 0-10 Nm. As ACL injuries occur during weightbearing conditions, it may be feasible that an external rotation torque could damage the ACL.50 Although a passive valgus torque during weightbearing conditions increases ACL strain compared with non-weightbearing conditions, the strain remains relatively constant over a wide range of torques. It is important to note that the strain in the posteromedial ACL bundle cannot be measured using current arthroscopic techniques. Cadaveric studies indicate that when a valgus load is applied to the knee joint from 0u to 90u of knee flexion, the posterolateral ACL bundle shows a nearly fourfold greater change in length compared with the anteromedial bundle.28 Therefore, measuring only the anteromedial bundle of the ACL may not appropriately assess the amount of strain that occurs in the total ACL during a valgus load.

Patellar Tendonitis

acute: reduce inflammation and restore strength/flexibility; chronic: induce certain amount of trauma; transverse friction massage; exercises at 3-4/10 on pain scale

Patellar Instability

acute: settling down effusion and trauma; chronic: enhance static stability (bracing); enhance dynamic stability (neuromuscular control exercises)

Biomechanical Dysfunction

alterations in foot/ankle mechanics, hip strength, leg length discrepancy, flexibility deficits that negatively impact force on patellofemoral joint

Medial Patellofemoral Ligament Injury

any issues with chronic ELPS or patellar instability

What is the management of ITB

nitial treatment consists of medications and ice to relieve pain and reduce inflammation, stretching and strengthening exercises (particularly the IT band), and modification of the activity that produces the symptoms. An orthotic or arch support may be prescribed to reduce friction to the bursa. Training techniques can be altered by lessening the amount of the training activity, changing the stride length, avoiding running on hills or stairs, changing the direction you run on a circular or banked track, or changing the side of the road you run on. An injection of cortisone may be recommended.

Biomechanical Dysfunction

treat cause of symptoms, not just symptoms

Global patellar pressure syndrome (GPPS).

GPPS occurs when there is a general and diffuse medial and lateral soft tissue tightness that results in the patella being excessively compressed within the throclea. This is more commonly see after direct trauma, immobilization due to fracture, or knee surgery with the development of arthrofibrosis. Have you ever had a patient lose patella mobility after an ACL reconstruction? This is a good example of GPPS. These patients may also have decreased superior patellar mobility as the knee is immobilized in flexion.

Meniscus Transplantation

Since 1984, numerous clinical studies have re- ported results of meniscus transplanta- tion. Differences in tissue processing, secondar y sterilization, preser vation, op- erative techniques, and rating schemes make com- parisons between studies difficult.17,75 Rath et al73 followed 22 patients with cryopreserved meniscal allografts for 2 to 8 years postoperatively.73 Eight menisci (36%) failed and were removed an average of 31 months postimplanta- tion. Histologic analysis of the torn allografts demon- strated greater than a 50% reduction in the number of meniscalfibrochondrocytes at the periphery com- pared with torn native menisci. Verdonk et al94 reported survival rates of 100 patients who had viable fresh) meniscus transplants. The mean cumulative survival time was similar for medial and lateral transplants (11.6 years). The cumulative survival rates for the medial and lateral transplants at 10 years were 74.2% and 69.8%, respectively. When a medial menis- cus transplant was combined with a high tibial osteotomy, the survival rate increased to 83.3% at 10 years. MRI signal intensity alterations of meniscus al- lografts are frequently reported postopera- tively.63,72,85,89,96 Potter et al72 followed 29 patients with meniscal allografts 3 to 41 months postopera- tively. Increased signal intensity was detected in the posterior horn in 15 knees and peripheral displace- ment at the body was noted in 11 knees; all of these knees had moderate or severe chondral degenera- tion. Histologic analysis demonstrated peripheral cel- lular repopulation, but a central core that was acellular or hypocellular with evidence of disorga- nized collagen fibers. Knees with mild chondral degeneration had no abnormalities noted in the meniscus allografts and demonstrated superior clin- ical results compared to those with severe chondral degeneration. We reported on the outcome of 40 consecutive cryopreserved meniscus transplants that were im- planted into 38 patients.63 The patients were exam- ined a mean of 40 months (range, 24-69 months) postoperatively. MRI was used to assess 29 of the transplants a mean of 35 months (range, 12-67 months) postoperatively. Transplant height, width, and displacement were measured during full92 or partial weight-bearing (loaded) conditions. A classifi- cation of meniscal transplant characteristics was devel- oped based on MRI, follow-up arthroscopy, clinical examination, and patient symptoms. Osteochondral autograft transfer (OAT) procedures were performed for femoral condylar defects with the meniscus trans- plant in 13 knees (37%). Knee ligament reconstruc- tions were done before the meniscus transplant in 4 knees and at the same time as the transplant in 4 knees. Before surgery, 27 patients (77%) had moderate to severe pain with daily activities; but at follow-up, only 2 patients (6%) had pain with daily activities (P.0001). While all patients had pain specifically located in the meniscectomized tibiofemoral compart- ment preoperatively (either with daily or sports activi- ties), only 10 had mild tibiofemoral pain at follow-up. The majority of patients (94%) believed their knee condition had improved and 77% were participating in light low-impact sports without problems. The mean displacement of the transplants in the coronal plane was only 2.2 1.5 mm (range, 0-5 mm), which was not considered clinically significant. Intrameniscal signal intensity was normal in 1, grade1in13,grade2in11,grade3in3,andcouldnotbe evaluated in 1 knee. One patient had signs of a

Which patient-related outcome measures should be used for the evaluation and follow-up of patients with anterior cruciate ligament injury? Level 2:

The IKDC and KOOS are validated (in Dutch) (Haverkamp et al. 2006, de Groot et al. 2008) as patient-related outcome scores. These knee-related scores are probably well-suited for patients with an ACL rupture (Roos et al. 1998, Irrgang et al. 2001). The Tegner score is an accepted activity score (Briggs et al. 2009); it is has not, however, been validated in Dutch. Recommendation. We recommend the combination of the Lachman test, pivot shift test, and anterior drawer test as a clinical outcome measurement. We recommend use of the IKDC subjective and the KOOS as patient-related outcome measures. It can be useful to adopt the Tegner score as an out- come measurement for activity.

signs and symptoms for PCL tear

A pop heard or felt at the time of injury Inability to straighten knee Significant swelling within six to eight hours Walking with a limp and knee giving way or buckling Diffuse knee pain, usually in the front half of the knee, behind the kneecap, or in the very back of the knee Pain that is worse with sitting for long periods, going up or down stairs or hills, and jumping

Overuse Syndromes tx

For tendonopathy, treatment begins with assessing the chronicity of symptoms. If acute, reduce inflammation and restore strength and flexibility. I hate to be vague, but I doubt you'll see a lot of patients that are this acute. Realistically, people put off treatment for months and end up with chronic tendonosis. This is another lengthy topic, but the key here is that the patellar tendon is not actually inflamed, it is degenerative due to a lack of healing blood supply (that is why the surgery for this is debridement to stimulate healing). Thus, traditional treatment to reduce inflammation is not going to work. In a way, you need to induce a certain amount of trauma, such as with transverse friction massage. I also recommend that general orthopedic patients need to feel about a 3-4/10 on a pain scale during exercises to actually stimulate healing. Any less and you probably aren't stressing the area enough and any more and you may overloading.

Management of ACL tear

Immediately after the trauma the RICE principle should be applied. A conservative approach is an option for some but surgical treatment is usually advised for those who participate in high demand sports. RICE and electrotherapy can be applied during several weeks ahead of the surgery in order to reduce swelling and pain, to attempt full range of motion and to decrease joint effusion. This will help the patient to regain better motion and strength after the surgery.

Meniscal Repair and Transplantation: Indications, Techniques, Rehabilitation, and Clinical Outcome INDICATIONS AND CONTRAINDICATION

Meniscal repair is indicated for patients under age 50 or those in their fifties who are athletically active. Tears in the peripheral one-third vascularized region5 are well suited for repair and have high success rates. Arnoczky and Warren previously described the vascularity of the menisci. The degrees of vascular penetra- tion were 10% to 30% of the width of the medial meniscus and 10% to 25% of the width of the lateral meniscus. A vascular synovial covering was noted on the anterior and posterior horn attachments, and a synovial fringe was described on the femoral and tibial articular surfaces of both menisci. While tears located in the central one-third region, which is less vascular, may be repaired, there must be 8 mm of intact meniscal tissue without fragmentation. Anatomic approximation and complete closure of all gaps at the tear site must be achieved to promote healing. Contraindications include tears located in the inner one-third region (rim width greater than 8 mm), tears with major tissue fragmentation or degen- eration, and tears with edges that cannot be reduced and approximated. Longitudinal tears less than 10 mm in length or incomplete radial tears that do not extend into the outer one-third of the meniscus are not repaired. The indications for meniscus transplantation are prior total meniscectomy, age of 50 years or less, clinical symptoms of pain in the involved tibiofemoral compartment or articular cartilage degeneration, and 2 mm or more of tibiofemoral joint space on 45°weight-bearing posteroanterior radiographs.77 The re sults of this operation are more favorable when it is done before the onset of advanced tibiofemoral joint arthrosis.61,63,72 Normal axial alignment and a stable joint are required, as untreated varus limb malalignment and ACL deficiency correlate with transplant failure.14,18,87,88 Contraindications for a meniscus transplant are advanced knee joint arthrosis, defined as less than 2 mm of tibiofemoral joint space on 45° weight-bearing posteroanterior radiographs and MRI evidence of flattening of the femoral condyle, concavity of the tibial plateau, and osteophytes that prevent anatomic seating of the transplant. Knee joint instability is a contraindication unless the patient is willing to un- dergo ligament reconstruction either before or with the meniscus transplant. Other contraindications in- clude knee arthrofibrosis, muscular atrophy, and prior joint infection. Axial malalignment of varus (weight-bearing line of less than 40% of the medial- lateral transverse width of the tibial plateau) or valgus (weight-bearing line of greater than 60%) is also a

Soft Tissue Lesions

There are a few common soft tissue lesions that can occur to the patellofemoral joint. Accurate diagnosis of these syndromes usually involves direct palpation to these areas and a certain mechanism of trauma to the area.

Direct Patellar Trauma

This is my least favorite pathology as I seem to always be a victim of direct patellar trauma myself. Have you ever hit your knee against a table leg? Every time I do, and it seems frequent, I think of the acute trauma my articular cartilage just took! This is also seen with patients falling on their knee, which is common up here in the northeast during the winter when it gets icy. Subjective exam should lead you this way, but you may have to probe, sometimes patients will forget that they fell 3 weeks ago or not correlate their symptoms with the incident. Patients in this classification can include bone bruises, articular cartilage lesions, and even fractures.

ACL Tear signs and symptoms

An audible pop or crack at the time of injury A feeling of initial instability, may be masked later by extensive swelling Swelling of the knee, usually immediate and extensive, but can be minimal or delayed Restricted movement, especially extension Possible widespread mild tenderness Tenderness at the medial side of the joint which may indicate cartilage injury Knee giving way or buckling

What is the outcome of different non-operative treat- ment modalities? level 1

Balance and proprioception training has a positive effect on joint position sense, muscle strength, experienced knee function, out- come of functional capacity, and return to full activity (Fitzger- ald et al. 2000, Cooper et al. 2005, Trees et al. 2005, 2007)

What is the outcome of different non-operative treat- ment modalities? level 2

Addition of open-chain strength training to an ACL rehabil- itation program has a positive effect on muscle strength of quadriceps and hamstring muscles and on functional recovery (Zatterstrom et al. 2000, Perry et al. 2005, Tagesson et al. 2008). Supervised training has more value than non-supervised training concerning muscle strength of the quadriceps and hamstring muscles, and on functional recovery (Zatterstrom et al. 1998, 2000).

Fat pad syndrome. tx

The patient should avoid excessive quadriceps activities, especially if this causes irritation to the fat pad as the patellar tendon can compress the area when contracting the quad.

5. Control the Knee Through the Hip

Again, I don't want to get to much into this as we will spend an entire chapter on this topic, but the importance of hip strength cannot be overlooked. Every patellofemoral patient should be assessed for hip weakness and poor dynamic control of their knee during functional activities. You will be shocked at how many of your patients have absolutely no strength outside of the sagittal plane. It is amazing. Emphasize the hip's ability to eccentrically control the valgus moment at the knee produced by hip IR and adduction. I can't say it enough, work on hip abduction and ER. This tip alone will greatly enhance your patellofemoral outcomes. More on this in an upcoming chapter

Clinical Concepts

The supervised physical therapy program is supple- mented with home exercises performed on a daily basis. The therapist must evaluate the patient thor- oughly to implement the appropriate protocol, and should examine the patient in the clinic and use therapeutic procedures and modality treatments re- quired for successful rehabilitation. For the majority of patients, 11 to 16 postoperative physical therapy visits are expected over the course of 9 to 12 months to produce a desirable result. Important postoperative signs the therapist must monitor include swelling of the knee joint or soft tissues, pain, gait pattern, knee flexion and extension, patellar mobility, strength and control of the lower extremity, lower extremity flexibility, and tibiofemoral symptoms indicative of a meniscal tear (Table 2). Patients are warned that an early return to strenu- ous activities, including impact loading, jogging, deep knee flexion, or pivoting, carries a definite risk of a repeat meniscus tear or tear to the transplant. This is particularly true in the first 4 to 6 months postopera- tively, where full flexion or deep-squatting activities may disrupt the healing repair sites or transplants. Plain radiographs (lateral and anterior-posterior) are obtained at 1 week postoperatively to verify the position of the osseous component of meniscus transplants, and at 6 to 8 weeks postoperatively to verify healing and retention of the bony portion of such as the Game Ready (Game Ready, Berkley, CA) cryotherapy machine, are used to provide compres- sion with the cold program (Figure 9). The patient is instructed to maintain elevation of the lower limb as often as possible during the first week after surgery. Patients are also fit and instructed in the use of a portable neuromuscular electric stimulator such as the EMPI PV 300 (EMPI, St Paul, MN), which we have found to be effective for quadriceps re-education and pain management (Fig- ure 10). Patients are instructed to use the device for 15-minute sessions, 6 times per day. This device is used until the patient displays an excellent voluntary quadriceps contraction. The initial 2-week-postoperative period sets the tone for the early program progression. Due to the location of the repair incision and the extensive nature of the repair or transplant, symptoms such as pain, swelling, quadriceps shutdown, range of motion (ROM) limitations, and saphenous nerve irritation are common postoperative complications. The clini- cian should monitor patient complaints or symptoms of posteromedial or infrapatellar burning sensations, posteromedial tenderness along the distal pes anserine tendons, tenderness of Hunter's canal along the medial thigh, hypersensitivity to light pressure, or hypersensitivity to temperature change. Early recogni- tion and treatment of these problems is critical for a successful outcome.

What is the management of PCL

Initial treatment should consist of the RICE principle, to relieve pain and reduce the swelling of the knee. Range of motion, stretching, and strengthening exercises are encouraged. The PCL has a complex structure and as yet cannot be replicated with surgery. Thus for most isolated PCL injuries, surgery is not recommended and rehabilitation is the treatment of choice. This includes reducing swelling, regaining knee range of motion, regaining quadriceps muscle control and strength, functional training, and education. Surgical treatment may be recommended for more severe tears involving other injuries to the knee.

MCL Tear o Pathology and MOI

MCL injuries mostly occur after secondary to a valgus load. When the force of the impact is big enough, some or all the fibres will tear. Mostly the deep part of the ligament gets damaged first, and this may lead to medial meniscal damage or anterior cruciate ligament damage.

what are the special tests/images

Special Testing: Valgus testing in 0 and 20 degrees flexion. Imaging: MRI if suspected grade III.

special tests for ACL tear

Special Tests: Lachman's test, Anterior drawer, Pivot shift Imaging: MRI

10. Gradually Progress Back to Activities

Lastly, as the patellofemoral patient progresses through the rehabilitation program, emphasis should shift towards functional activities that replicate activities specific to each patient. The rate of progression with functional activities is dictated by the patient's unique tolerance to the activities. Exercise must be performed at a tolerable level without overstressing the healing tissues. Pathological loading that produces detrimental stress on the patellofemoral joint should be avoided to prevent exacerbations of symptoms. Functional stresses are gradually increased leading to a steady return to function. The functional progression of activities should follow a progressive and sequential order to ensure proper amounts of stress are applied to facilitate healing without producing disadvantageous forces.

Leg Length Discrepancy.

Leg Length Discrepancy. I chose to include leg length discrepancy with the group of distal forces as the impact of a longer leg length tends to impact the positioning of the foot and ankle. The longer leg will tend to have a toe-out and pronated position to compensate for the longer length.

PCL Tear o Pathology and MOI

PCL tears are caused by a force that exceeds the strength of the ligament. This injury may be a result of a noncontact injury (excessively straightening the knee) or may result from contact, such as getting tacked at the knee (especially forced bending) or landing on the knee

Direct Patellar Trauma

Ouch, I hate even thinking about direct patellar trauma. My knee hurts just thinking of it! With this pathology, we are worried about either a patellar fracture or articular cartilage damage. Once the initial trauma subsides, treatment should attempt to enhance cartilage healing. This means frequent ROM of the knee. In addition to standard PROM, this can be in the form of a bike, if minimal resistance is applied. You do not want to compress too much but a little bit of motion is better for cartilage healing. I also like the pool for these patients if possible. You'll have to limit patellofemoral joint reaction forces with exercises but this should subside with time. If symptoms do not resolve, the patient should be sent back to their doctor for further evaluation to rule out a fracture or an OCD type cartilage lesion.

IT band friction. tx

Similarly to above but with the lateral femoral condyle. Lengthening massage to the IT band has been helpful in my practice.

Fat pad syndrome.

The fat pad of the knee is highly vascularized and has rich nerve fibers. When a patients falls on their knee, they may inflame this structure. You can easily palpate on either side of the patellar tendon and find discomfort. Be sure to assure that you are not palpating the patellar tendon as treatment for this will vary.

A Systematic Review of the Effects of Therapeutic Taping on Patellofemoral Pain Syndrome

(PFPS) is a condition presenting with anterior knee pain or pain behind the patella 1,2 retropatellar pain). It is commonly experienced during running, squatting, stair climbing, prolonged sitting, and kneeling.3,4 In the patellofemoral joint, the patella serves as a link to converge the fibers of the quadriceps femoris muscle group to increase its lever arm and maximize its mechanical advantage.5,6 To ensure this functional efficacy, maintaining the patellar alignment in the trochlear groove of the femur is necessary. Malalignment of the patella, or altered patellar tracking, may be a predisposing factor for patellofemoral pain, chondromalacia, and articular cartilage degeneration.1,2,5 Several factors may be associated with patellar malalign- ment. An increase in Q angle (more than 15) may increase the lateral pull of the patella, causing the patella to glide on the lateral ridge of the femoral groove and producing pain.5,7,8 Tightness of the muscles that cross the knee joint may have an effect on patellar alignment.5 A tight rectus femoris muscle can limit patellar movement, reducing the functional and me- chanical efficacy of the patellofemoral joint.5 A tight iliotibial band may pull the patella laterally during knee flexion, where- as tightness in the hamstring muscle group may increase pa- tellofemoral joint reaction forces because of an increased knee flexion moment.5,9 Gastrocnemius tightness may limit ankle dorsiflexion, which can result in increased subtalar joint pronation and tibial internal rotation, contributing to abnormal pulling of the patellar tendon and the patellar malalignment

Conditioning

A cardiovascular program may be initiated as early as 2 to 4 weeks postoperatively if the patient has access to an upper body ergometer (Table 5). Station- ary bicycling, with the seat height adjusted to its highest level based on patient body size and use of low resistance level, is begun 7 to 8 weeks postopera- tively. If the patient has patellofemoral changes, a recumbent bicycle may be substituted. Additionally, water walking may also be initiated during this timeframe. Walking in water waist high will decrease the impact load to the knee by 50%. To protect the healing meniscus, swimming with straight leg kicking and dry land walking programs are initiated between the ninth and twelfth weeks. At this time, patients that had a meniscus repair may also begin using stair climbing, elliptical cross-trainers, or cross-countr y ski machines. Protection against high stresses to the patellofemoral joint is required in patients with symptoms or articular cartilage damage. If a stair climbing machine is tolerable, we suggest maintaining a short step and using lower resistance levels. The cardiovascular program should be done at least 3 times a week for 20 to 30 minutes, and the exercise performed to at least 60% to 85% of maximal heart rate.

9. Normalize Gait

Gait training is also a critical component to patellofemoral rehabilitation. A variety of factors contribute to antalgic and inefficient gait patterns including joint effusion, pain, soft tissue tightness, and scar tissue formation. Strategies used to minimize the flexed knee gait pattern that is commonly exhibited by patellofemoral patients include minimizing joint effusion and enhancing sift tissue flexibility, particularly the hamstring and gastrocnemius musculature. Specific techniques include retrograde walking over cones. This particular exercise requires adequate quadriceps control and involves the patient ambulating while high stepping over successive cones. As the patient moves backward, the foot strikes the ground in a toe to heel pattern to produce an extension moment at the knee.

Medial patellofemoral ligament injury. tx

hese patients should actually have treatment similar to the ELPS patient above. A brace to control lateral patellar translation may be helpful too.

Apophysitis

of the tibial tuberosity or inferior patellar pole can be a pretty limiting pathology. The two best treatments are time and avoiding the activity that causes symptoms. That means many youth injuries will need to take some time off from basketball, or whatever may be causing their symptoms, as their body grows and the symptoms resolve. Treatment is basically to reduce symptoms, there isn't much you can do to actually "heal" the injury.

Running and Return to Sports Activities

A running program is begun at approximately 20 weeks postoperative in patients who had peripheral meniscus repairs and who have no more than a 30% deficit in average peak torque for the quadriceps and hamstrings on isometric testing performed on a Biodex dynamometer (Biodex Corp, Shirley, NY). Isometric testing is performed at an angle of 60° of knee flexion. Initial testing at this angle places the knee in a protected position for both the meniscus and patella. Progression to ROM testing at high speeds is important, but the initial goal is to test the integrity of the quadriceps and hamstring muscula- tures. Other testing parameters worth evaluating in- clude peak torque to body weight ratios, agonist- antagonist ratios, and time to peak torque values. A walk-run combination is initially begun, using running distances of 18, 37, 55, and 91 m. Running speed is one quarter to one half of the patient's normal running speed and is gradually progressed. Once the patient can run straight ahead at full speed, lateral and crossover maneuvers are added. Short distances, such as 18 m, are used to work on speed and agility. Side-to-side running over cups may be used to facilitate agility and proprioception. Figure-of- eight and carioca running drills are also useful. Sport-specific drills and cutting patterns of 45° and 90° angles may be implemented as well, based on the patient's athletic goals. This program is begun at approximately 30 weeks postoperative in patients who had complex meniscus repairs, but is delayed until at least 12 to 24 months postoperatively after transplan- tation. Repeat Biodex testing is typically performed monthly, progressing from isometric testing for the first 6 months to isokinetic testing at speeds of 180° and 300° per second. This testing not only provides the patient with feedback on performance, but also serves to assist the clinician with program progres- sion. Goals for testing should be at least 70% to begin running and 90% for full activity for the bilateral torque comparisons, approximately 60% for agonist-antagonist ratios, and torque-body weight ra- tios will be based on age, sex, and body weight parameters. Return to sports activities is based on successful completion of the running and functional training program. Muscle and functional testing should be within normal limits, and a trial of function is encouraged, during which time the patient is moni- tored for overuse symptoms. Patients who undergo meniscus transplantation are advised to avoid return- ing to high-impact, strenuous athletics due to the joint damage that is frequently present and the inability of the meniscus transplant to completely restore normal load-sharing function.

ACL Tear o Pathology and MOI

ACL injuries can occur from direct contact, indirect contact, or no contact. Most common are the non contact injuries caused by forces generated within the athlete's body while most other sport injuries involve a transfer of energy from a source external to the athlete's body. A cut-and-plant movement is the typical mechanism that causes the ACL to tear: sudden change of direction or speed with the foot firmly planted. Direct impacts to the front of the tibia or stiff-legged landings are other frequently reported causes. Women are 3-6 times more prone to have the ACL injured then men. A wider pelvis requires the femur to angle toward the knee, lesser muscle strength gives less support to the knee and hormonal variations may alter the laxity of ligaments.

What are the relevant parameters that influence the indication for an anterior cruciate ligament recon- struction? Level 1:

Actual age is not a factor of importance for the decision to perform an ACL reconstruction (Barber et al. 1996, Sloane et al. 2002). Younger patients are entitled to an ACL reconstruction ear- lier because of their higher activity level (Barber et al. 1996, Ferrari and Bach 2001, Sloane et al. 2002, Dunn et al. 2004).

What is the optimal postoperative treatment (after the first postoperative check-up, concerning rehabili- tation, resumption of sports, and physiotherapy)? Level 2

Addition of neuromuscular training to the rehabilitation pro- gram will have a better outcome than strength training alone (Risberg et al. 2007). An exercise program with early open-chain exercises (4 weeks postoperatively) will lead to more laxity with ham- string grafts than late open-chain exercises (12 weeks postop- eratively) (Heijne and Werner 2007). Consideration. The literature retrieved gives insufficient scientific information for us to be able to give advice concern- ing work, daily living, and resumption of sports that can be applied to every patient. On every occasion of the rehabilita- tion program, the treatment team should be aware of signals such as knee pain, swelling, feeling of warmth, and range of motion. With this information, an individual schedule can be implemented concerning daily living, work, and sports to ensure a swift and safe rehabilitation. Recommendation. We recommend combining strength with neuromuscular training in the postoperative treatment. It is recommended that only closed-chain exercises be used in the early rehabilitation phase. There is no reason for the use of a brace in the postopera- tive treatment period after an anterior cruciate ligament recon- struction. Heavy physical activity in labor or sports should not be resumed within 3 months of surgery.

6. Enhance Soft Tissue Flexibility

Another principle of patellofemoral rehabilitation is the enhancement of joint flexibility with emphasis on quadriceps, hamstrings, hip adductors, gastrocnemius, and iliotibial band stretching. Any deficit in flexibility of these areas will cause significant biomechanical faults throughout the kinetic chain. Rehabilitation should focus on restoring full passive knee extension initially to minimize the development of a flexed knee posture exhibited by some patients with patellofemoral disorders. Ambulating and performing daily activities with a knee flexion contracture may result in increased patellofemoral joint reaction forces and requires a great deal of motor control to stabilize the knee joint. Full passive knee extension is important for improved quadriceps activity and also allows the knee to lock out while standing, thus allowing relaxation of the surrounding musculature. Restoring full knee flexion is also a significant priority. In postoperative patients, knee flexion is gradually restored especially in the presence of an effusion. In non-operative patients, knee flexion is gradually restored through controlled stretching exercises. The goal of restoring full knee flexion is not merely reestablishing quadriceps flexibility but improving soft tissue flexibility of the retinacular tissues as well. Witvrouw et al (AJSM 2000) prospectively studied the risk factors for the development of anterior knee pain in the athletic population over a 2-year period. A significant difference was noted in the flexibility of the quadriceps and gastrocnemius muscles between the group of subjects that developed patellofemoral pain and the control group, suggesting that athletes exhibiting tight musculature may be at risk for the development of patellofemoral disorders.

Biomechanical Dysfunction Tx

As previously stated in my post on the classification of patellofemoral pain, the knee appears to take a good amount of stress when biomechanical faults are present both proximally and distally within the kinetic chain. Alterations in foot and ankle mechanics, hip strength, leg length discrepancy, flexibility deficiencies, and any combination of these factors can have a negative impact on the forces observed at the patellofemoral joint. Not only can biomechanical dysfunction lead to increased stress, it can also lead to chronic adaptations over time. Take for example someone with weak hip external rotation. This could lead to a dynamic inability to control the hip adduction and IR moment at the knee and cause the femur to rotate into internal rotation during activities. This will cause the patella shift laterally and can cause articular cartilage and soft tissue changes that will mimic a typical ELPS patient. You can loosen up the lateral soft tissue but without treating the true cause, the hip weakness, symptoms will continue to occur. This will be discussed in greater detail in a future chapter in this eBook as this is an important factor to consider.

What is the optimal timing for surgery for an anterior cruciate ligament injury? Level 2

At long-term follow-up (7 years) of a subacute reconstruction (within 6 weeks) gave better outcome for range of motion, work participation, and degenerative change than late recon- struction (Järvelä et al. 1999). Recommendation. The indication for a reconstruction is persistent instability of the knee with complaints of giving way. This diagnosis is difficult to make in an acute situa- tion. We therefore recommend that anterior cruciate ligament reconstruction should not be performed in the first weeks after trauma, in order to minimize the risk of operating on an asymptomatic patient. If the indication for anterior cruciate ligament reconstruc- tion has been defined, we recommend performing the recon- struction in a timely manner in order to minimize the risk of additional damage to the cartilage and/or meniscus. The patient with a delayed reconstruction (6 weeks to 3 months post-trauma) can resume his or her physical activity sooner—with a greater chance of obtaining higher activity scores—than a patient with a late reconstruction (more than 3 months after trauma). In the long term, delayed reconstruction gives a better range of motion and less degenerative changes than a late recon- struction.

Balance and Proprioceptive Training

Balance and proprioception exercises are initiated when patients achieve partial weight bearing. Crutches are used for support during these exercises until full weight bearing is achieved. Initially, patients perform weight shifting from side-to-side and front-to- back. Then, cup walking is encouraged to develop symmetr y between the surgical and contralateral limbs, hip and knee flexion, quadriceps control during midstance, hip and pelvic control during midstance, and adequate gastrocsoleus control during push-off (Figure 12). Tandem balance can be initi- ated during the partial weight-bearing phase to assist with position sense and balance. The single-leg bal- ance exercise is also beneficial and is done by pointing the foot straight ahead, flexing the knee to 20° to 30°, extending the arms outward to horizontal, and positioning the torso upright with the shoulders above the hips and the hips above the ankles. The objective is to stand in position until balance is disturbed. A mini-trampoline makes this exercise more challenging after it is mastered on a hard surface. A variety of devices are available to assist with balance and gait retraining, including lower-end devices consisting of Styrofoam half rolls, whole rolls, and the Biomechanical Ankle Platform System (BAPS, Camp, Jackson, MI). Patients walk (unassisted) on Styrofoam half rolls to develop balance, quadriceps control in midstance, and postural positioning. The BAPS board is used in double-leg and single-leg stance to promote proprioception.

Patellar Compression Syndromes

Heat/whirlpool to warm up the tissue and prepare for treatment Continuous ultrasound to tight area. We can argue about the efficacy of US but I think this is a good time for it's use. I am aggressive - continuous, jack it up to 2.0 and keep the area small, of course use patient tolerance as a guideline! Soft tissue massage progressing to aggressive massager or friction as inflammation subsides. Specific trigger point and muscle energy techniques can be helpful as well, especially in the patient with tight hips that are contributing to ELPS. Patellofemoral joint mobilization in whatever direction is needed For a patient with ELPS, I would consider trying patellar taping. I don't use this to really change the alignment or biomechanics of the patellofemoral joint, study after study shows this does not happen with tape. I do however believe that the tape can be applied to potentially cause a low-load, long-duration stretch of the soft tissue/retinaculum around the knee. Remember, that stress and tension of the surround tissue may be the cause of patellofemoral pain. Generalized stretching of the lower extremity with specific emphasis on tight structures impacting the PF joint (i.e. the IT band). As with anything else related to the patellofemoral joint, look at the hip and foot to see if any biomechanical factors are contributing to lateral tightness of the knee. There are also some things that should be avoided in these patients: Bike riding - it is just going to compress the PJ joint and cause more symptoms Exercises with high PF joint reaction forces, such as knee extension. Again, just going to cause more compression and more irritation. In the patient with global compression syndrome, I would recommend you avoid taping. Again, just going to cause undue compression. In general, I would be conservative in strengthening exercises for the global compression patient. Straight leg raises, pool work, and other basic exercises should be enough while you loosen up the soft tissue.

Differential Diagnosis of Patellofemoral Pain

In 1998, one of the most influential rehabilitation publications of the last 2 decades was published on treatment of the patellofemoral joint. Four of the leaders and pioneers of sports medicine and orthopedic rehabilitation - Kevin Wilk, George Davies, Bob Mangine, and Terry Malone - teamed up to develop a classification system for the differential diagnosis of patellofemoral pathologies. This manuscript was the first to offer treatment strategies based on specific diagnoses for patellofemoral pain. Today, this manuscript still holds extreme value and if you haven't read it, I highly recommend finding a copy. By far the most critical component of treating the patellofemoral joint is an accurate diagnosis. I will always challenge me students in this regard - find the cause of their symptoms and STOP using "patellofemoral pain" as a diagnosis. At first this can seem like a daunting task as the true source of patellofemoral pain can be misleading. However, using a classification system to group types of diagnoses can be extremely helpful in the formation of your treatment program.

Contact Area of the Patellofemoral Joint

In addition to understanding when the patellofemoral articulates, it is important to discuss the area of contact. Obviously, contact between the patella and trochlea that covers a larger surface area will distribute the load over a greater area. This is a driving factor in exercise selection and will be talked about below. At 30 degrees, the area of patellofemoral contact is approximately 2.0cm2. The area of contact gradually increases as the knee is flexed. At 90 degrees of knee flexion contact area triples, increasing up to 6.0cm2. As you can see, The contact area initially is small and gradually increases as the joint become more congruent. Alterations in Q-angle are often associated with patellofemoral disorders and may alter the contact areas and thus the amount of joint reaction forces of the patellofemoral joint. Huberti and Hayes examined the in vitro patellofemoral contact pressures at various degrees of knee flexion from 20 - 120 degrees. Maximum contact area occurred at 90 degrees of knee flexion and was estimated to be 6.5 times body weight. A increase or decrease in Q-angle of 10 degrees resulted in increased maximum contact pressure and a smaller total area of contact throughout the range of motion. This information may be applied when prescribing rehabilitation interventions so that exercises are performed in ranges of motion that place minimal strain on damaged structures.

Surgical treatment— which kind of graft gives the best result in an anterior cruciate ligament reconstruction? level 3

In different modern methods using metal or resorbable screws, graft fixation strength is similar (Brand et al. 2000, Harvey et al. 2005). Recommendation. Considering clinical outcome measure- ment, there is no direct preference for the use of either auto- graft or allograft for anterior cruciate ligament reconstruction. Both graft types lead to good clinical results. Radiated allografts fail more often than non-radiated allografts. Stretching of allografts before the reconstruction is unnec- essary. Bone-patellar-tendon-bone and hamstring reconstructions give good results, stability, and low complication rates. Ham- string reconstruction results in significantly less anterior knee pain. Both single- and double-bundle hamstring reconstruc- tion give good functional results. With our current scientific knowledge, there is no preference for either technique. Dou- ble-bundle reconstruction is a more time consuming and tech- nically more demanding procedure than single-bundle recon- struction. Use of synthetic graft or ligament augmentation is not rec- ommended because of inferior results and increased compli- cations in long-term follow-up. There is no scientific basis for making recommendations as to the choice of type of fixation device for the different grafts.

Level 2:

It is likely that, when physical examination is conducted well, an MRI has no added value, since it will seldom change the diagnosis or the treatment strategy (Liu et al. 1995, Gelb et al. 1996, Kocabey et al. 2004). Recommendation. In order to maximise the diagnostic accu- racy for an anterior cruciate ligament injury, it is recommended that the Lachman test, pivot shift test, and anterior drawer test of the knee be performed. Having an experienced investigator enhances the reliability of this physical examination. MRI has no additional value when physical examination has shown anterior-posterior or rotational instability of the knee, suggesting an anterior cruciate ligament injury. However, MRI is a reliable additional investigation to establish other intraarticular lesions.

The Influence of the Foot and Ankle of Patellofemoral Pain

Just as forces located proximal to the knee can have a significant impact on the patellofemoral joint, forces distal to the knee may also contribute. Treatment for patellofemoral patients should include a thorough assessment of the foot and ankle to establish biomechanical factors that need to be addressed. Orthotic fabrication is often necessary, though off-the-shelf orthotics have had some success in the literature. Pronation. Excessive pronation of the foot causes a reciprocal internal rotation moment of the tibia. This turn increases the resultant Q-angle at the knee. As we previously discussed in our previous post on the biomechanics of the patellofemoral joint, an increased Q-angle will cause a greater amount of force on a more focal portion of the patella. Furthermore, an internal rotation moment of the tibia also results in internal rotation of the femur and a more laterally displaced patella. This may be a cause of ELPS as discussed previously when we discussedthe differential diagnosis of patellofemoral pain.

McConnell5 suggested 3 components of patellar orientation that need to be assessed before patellar tape is applied:

McConnell5 introduced a rehabilitation program that incor- porates patellar taping techniques to improve patellar tracking within the patellofemoral groove, as well as stretching of lat- eral knee soft tissues, VMO strengthening, and closed kinetic chain training. The McConnell patellar-taping program is in- tended to correct patellar tracking by medializing the patella, allowing patients to engage in pain-free physical therapy exercises.22 1. Glide component. The amount of gliding is characterized by the distance between the midpoint of the patella and the medial and lateral femoral epicondyles (Figure 1A and B). Patellar glide depends on the tightness of the static lateral structures as well as the contribution of the VMO activity relative to the vastus lateralis. 2. Tilt component. Patellar tilt is characterized by the differ- ence in the heights of the medial and lateral borders of the patella (Figure 2A), which indicates the tightness of the lateral structures (especially the lateral retinaculum). With a lateral patellar tilt, the anteromedial border of the patella is more anterior than the anterolateral border of the patella (Figure 2B). 3. Rotation component. Internal and external rotation of the patella is represented by the alteration in alignment between the longitudinal axis of the patella (from the superior to the inferior poles) and the longitudinal axis of the femur (Fig- ure 3A). Excessive internal rotation of the patella may be present in PFPS patients (Figure 3B), possibly because of the weak VMO and tight lateral structures such as the lat- eral retinaculum and iliotibial band. Although the McConnell patellar-taping program has be- come a popular practice among athletic trainers and other health care professionals treating PFPS, its true clinical effi- cacy is not well established. The purpose of this systematic review is to assess the current literature on patellar taping to investigate its effectiveness related to selected outcome mea- sures: controlling patellofemoral pain, improving patellar alignment, and enhancing neuromuscular control.

Patellar Instability

On the other side of the spectrum is patellar instability, which can range from an acute dislocation to recurrent instability. On examination, patients will have excessive patellar mobility laterally. This is often associated with a shallow trochlea, so many patients may be predisposed to this condition. I would suspect this with the patient with chronic subluxations. Also, acute episodes of subluxation or dislocation may result in rupture of the medial patellofemoral ligament and subsequent medial pain. Patients with chronic subluxation usually don't have as much sensitivity medially as their tissue adapts and/or tears over time. Try this - perform patellar gliding at 0 degrees of flexion and then again at ~30 degrees of flexion. If the patella continues to have excessive gliding at 30 degrees, then they likely have a shallow trochlea and poor static stability. These patients are challenging to treat as the static stability is a primary cause of their symptoms.

Overuse Syndromes

Overuse syndromes include patellar tendonitis and less commonly quadriceps tendonitis superiorly. Patellar tendonitis most commonly occurs at the inferior pole of the patella, but may also occur mid- tendon or at the tibial tuberosity. Patients will present with typical symptoms of a tedonopathy. Two types of apophysitis can occur in the knee. These are common in adolescents during growth spurts and in athletes participating in jumping sports. These can easily be palpated and may be seen I'm not a big fan of naming things after people as they don't offer any description of what the pathology is so I will use two versions of the terminology. Traction apophysitis of the tibial tuberosity (Osgood-Schlatter). Traction apophysitis of the inferior patellar pole (Sindig-Larsen-Johansson). As you can see, there are many different pathologies that can occur to the patellofemoral joint. The above list is not intended to be all-encompassing, but rather to create categories of diagnoses that share similar treatment guidelines. There are other potential source of PF issues, including neurologic origins from the lumbar spine or reflex sympathetic dystrophy, however I wanted to keep this discussion orthopedic. Once I rule out orthopedic issues I will explore other origins and a likely referral back to the doctor or specialist.

Patellar Compression Syndromes

Patellar compressive syndromes are described as pathologies involving excessive compression between the patella and the trochlea due to tight surround soft tissue. These can result in significant changes to the articular surfaces of the patella and trochlea over time. This can be broken down into two distinct types of compression syndromes: Excessive lateral pressure syndrome (ELPS). ELPS was originally described as occurring when the patella is overconstrained by soft tissue tightness, specifically the lateral retinacular tissue. The patient will exhibit a lateral tilted and/or shifted patella and decreased medial glide. There is often times medial discomfort as the medial retinacular tissue is stretched due to a laterally displaced patella. I often find palpating the medial patellofemoral ligament elicits a decent amount of discomfort. I believe proximal and distal influences in the kinetic chain also effect the alignment of the patellofemoral joint and can cause an ELPS-like syndrome, though through a different mechanism. This should be assessed and is discussed more below.

Patellofemoral Joint Reaction Forces

Patellofemoral joint reaction forces are observed during all movements of the knee. Often times, it is the goal of rehabilitation to exercise the lower extremity while minimizing patellofemoral joint reaction forces. Forces occur from a combination of: Articulation and contact area Resultant force vector between the quadriceps and patellar tendon Muscle contraction We have already discussed the articulation and contact area. Again, joint forces are reduced when distributed over a large surface area. When we discuss lever arms, remember that the patella's true function is to increase the mechanical advantage of the quadriceps muscle. Take a look at the diagram below, notice how the resultant force (red arrow) vector increases as the knee flexes and the line of pull from the quadriceps and patellar tendons causes a more compressive force? I wish it were that simple and we could say that joint reaction forces are always highest as the knee flexes. Unfortunately, we have to take muscle contraction into consideration as well. The quadriceps is designed to cause compression of the patellofemoral joint. The force of the quadriceps is greatest at terminal knee extension, that is why patients with patellectomies have such a difficult time extending their knees, they lost the biomechanical advantage of the patella and cannot produce enough quadriceps force to fully extend the knee. Now put the contact area together with the quadriceps force. The quadriceps provides the greatest compressive force near extension when the contact area of the patellofemoral joint is smallest. Thus, a high force on a small area produces considerable patellofemoral joint reaction forces. To demonstrate just how significant these forces are, take a look at the below table that I put together from various sources for a 200 pound person. Notice how deep squatting applies close to 4000 lbs of force to the patellofemoral joint (still want to squat?).

Supination.

Patients labeled as "pronators" seem to get all the attention, but excessive supination is likely just as bad. Not only do you diminish the foot's ability to dissipate force, supination will result in external rotation of the tibia and more force to the patella. You can see that the position of the foot and ankle when the foot hits the ground is important to evaluate as it will alter the arthrokinematics and patellofemoral joint reaction forces. It can not be stressed enough that it is imperative that the proximal and distal aspects of the kinetic chain need to be evaluated and treated in patients with patellofemoral pain. I am sure that your outcomes will begin to improve by not neglecting this important aspect of treatment

Which findings or complaints are predictive of a bad result of an anterior cruciate ligament injury treatment? Level 3

Persistent subjective knee instability has a negative influence on the outcome of both nonoperative and operative treatment. Treatment outcome is negatively influenced by undergoing multiple knee interventions of any kind (Meunier et al. 2007). An extension deficit before the operation can have a nega- tive effect on the outcome of an ACL reconstruction (Mauro et al. 2008). A strength deficit of more than 20% of the hamstring and quadriceps muscles compared to the uninjured side can have a negative effect on the outcome of an ACL reconstruction (de Jong et al. 2007, Eitzen et al. 2009). Cartilage and/or meniscal damage can have a negative effect on the functional result of the treatment of an ACL injury (Williams et al. 2000, Meunier et al. 2007, Kowalchuck et al. 2009). Continued participation in "high-risk sports" predisposes the knee for injury of the cartilage, the meniscus, and the pos- sibly reconstructed ACL—increasing the risk of re-rupture, secondary surgery, and knee osteoarthritis (Fink et al. 2001, Salmon et al. 2005, Meuffels et al. 2009). There is insufficient evidence to prove the protective effect of an ACL reconstruc- tion against knee osteoarthritis (Fithian et al. 2005, Gregory et al. 2008, Joseph et al. 2008, Meuffels et al 2009, Slauterbeck et al. 2009). Leg malalignment could have a negative influence on the outcome of an ACL reconstruction. Combining an ACL reconstruction and a correcting osteotomy could make the outcome of the ACL reconstruction more predictable (Williams et al. 2000). There is no clear evidence to show that the patient's gender influences the outcome of an ACL reconstruction (Salmon et al. 2005, Heijne et al. 2008, Slauterbeck et al 2009). Consideration. From a patient's point of view, the definition of a "bad result" may differ from the specific medical-techni- cal definition. It is important to give clear counseling about the expected activity level in both the short and long term. The uncertainty of a nonoperative treatment can be more difficult to accept for a sports person at a high level than for a person who is more interested in sport for recreation, or an elderly patient. One should also take the working circumstances of the person involved into consideration. Recommendation. An anterior cruciate ligament reconstruc- tion should be performed only when a full extension of the knee is possible and the synovial reaction is minimal. During the preoperative preparations, a possible muscle strength deficit of the injured leg should be treated. In the presence of knee malalignment and anterior cruciate ligament insufficiency, correction of the leg alignment should be considered, possibly in combination with an anterior cruci- ate ligament reconstruction. It is recommended that the patient be informed that par- ticipation in high-risk sports or heavy knee labor increases the risk of cartilage damage, meniscal damage, and damage to the reconstructed anterior cruciate ligament, which could result in a re-rupture, secondary surgery, or knee osteoarthritis

Have We Solved the Patellofemoral Mystery?

Probably not, but although the patellofemoral joint may still be a complicated area of sports medicine, I hope that this eBook has helped take the some of the mystery out of patellofemoral pain. In putting the pieces of this series together, remember to: Understand the source of patellofemoral pain and realize it might not be from "chondromalacia." Perform a thorough examination and attempt to identify a specific diagnosis, lets stop using the term "patellofemoral pain" and describe the actual diagnosis! Consider the basic principles of patellofemoral pain rehabilitation, including understanding the biomechanics of the joint and the biomechanics during exercise. Look proximal and distal within the kinetic chain to identify a potential true "source" of patellofemoral pain and stop treating the "symptoms!"

8. Enhance Proprioception and Neuromuscular Control

Rehabilitation programs must also include drills designed to restore proprioceptive and neuromuscular control skills in patellofemoral patients. Proprioception and postural balance training begins immediately postinjury or postoperatively. Specific drills initially include weight shifting side-to-side, weight shifting diagonally, mini-squats, and mini-squats on an unstable surface such as a tilt board. As the patient advances, tilt board squats can be progressed from double leg to single leg. Perturbations can further be added to challenge the neuromuscular system. Initially, the clinician can apply manual perturbations. As the patient sustains a vertical squat on a tilt board at 30 degrees of knee flexion, the clinician adds perturbations by tapping the board with his or her foot. Ball tosses can be incorporated with manual perturbations to provide additional challenge. The patient progresses to perform a vertical squat to 30 degrees of knee flexion while performing a chest-pass with a 3-5 pound weighted ball. The rehabilitation specialist continues to add manual perturbations by tapping the board. Ball throws are progressed from chest-passes to side-to-side throws, and then overhead soccer throws. Again, these exercises can be progressed from double-leg to single-leg stance to further challenge the patients neuromuscular control. Depending on their sport participation, jump and landing training may also be necessary to teach the athlete how to avoid detrimental positions.

7. Improve Soft Tissue Mobility

Soft tissue mobility is another rehabilitation principle that must be addressed. The goal of rehabilitation is to restore the soft tissue flexibility of the medial and lateral retinacular and capsular tissues. This may assist in controlling patellofemoral joint reaction forces by balancing the soft tissue pliability medially and laterally, and by correcting a possible tilt or rotation of the patella. Additionally, patellar mobilization techniques should be utilized to restore superior and inferior patellar mobility as well. Treatment techniques include patellar mobilizations and the application of patellar tape. While taping of the patella has received conflicting reports in the literature regarding its efficacy for correcting biomechanical deficits of the patella, taping may assist in restoring soft tissue flexibility by providing a low-load prolonged stretch of the retinacular tissues. Study after study shows that tape does not impact patella position or tracking (don't get me wrong there are some that show that it does, but there are more that says tape does not). My personal belief is that this is the reason for a reduction in symptoms with the application of tape. Remember that the source of patellofemoral pain may not be from the articular cartilage but rather from the retinacular tissue. The utilization of a brace which imparts a medial glide or force to the patella may also be beneficial. There are many on the market and I truly have no preference at this time. It seems like a new and improved brace comes out every 6 months. Preliminary MRI studies have documented the effectiveness of bracing.

Scientific evidence Level 1:

The Lachman test is the most valid stability test at the physi- cal examination of the knee, with a sensitivity of 85% and a specificity of 95% (Solomon et al. 2001, Scholten et al. 2003, Benjaminse et al. 2006). Performance of a complete physical examination of the knee (Lachman test, pivot shift, anterior drawer test) has a higher sensitivity and specificity than a partial investigation (Solomon et al. 2001). MRI is a valid and safe non-invasive diagnostic tool for diagnosing anterior cruciate ligament injury, with a high sen- sitivity and specificity (both 94%) (Oei et al. 2003, Crawford et al. 2007).

CONCLUSIONS

The McConnell method of patellar taping has been a pop- ular practice among athletic trainers and other health care pro- fessionals when treating patients with PFPS. However, the clinical evidence for the success of this intervention is still unclear. An insufficient number of randomized controlled tri- als, inconsistency of tape application techniques, and variance in measurement of specific outcome variables limit the strength of clinical efficacy and evidence. We have attempted to present the current information re- garding the efficacy of patellar taping on different outcome variables. Although the precise mechanisms are still unclear, patellar taping seems to significantly reduce perceived pain and improve function in patients with PFPS. Additionally, none of the reviewed studies demonstrated detrimental effects with patellar taping. Therefore, patellar taping may be a low- cost, noninvasive intervention to relieve symptoms in patients with PFPS. Regardless of the choice of therapeutic interven- tion, it is important to thoroughly understand the mechanisms and causes of the patient's patellofemoral pain. The clinician should remember that the patellofemoral joint is only one part of the dynamic lower extremity chain and that it is critical to identify the source of the problem and use appropriate tech- niques to correct that problem to ensure optimal results. Therefore, it seems prudent to use a combination of various interventions based on the individual patient's symptoms and causes. Further research is needed to evaluate the effectiveness of patellar taping and possibly the mechanisms for treating patellofemoral pain. However, it appears that, based on the current literature, patellar taping may provide a useful tool to the clinician in treating PFPS and does not seem to exacerbate the symptoms.

What are the relevant parameters that influence the indication for an anterior cruciate ligament recon- struction? Level 3

The activity level of the patient is probably the most important predictor for the necessity to perform an ACL reconstruction. The more the patient is active in pivoting sports, the greater the chance that an operation is necessary to reach an accept- able activity level (Daniel and Fithian 1994). Reconstruction of the ruptured ACL might reduce the chance of further meniscal and/or cartilage damage (Dunn et al. 2004). Consideration. Timing of the operative procedure is an important issue. The reconstruction should be performed at the time that the knee function has been optimized, and the synovial reaction has quietened down. Other considerations such as cartilage damage or degeneration can influence the choice of an operative procedure. From a patient's point ofview, other non-medical motives can play an important role. Professional or upcoming talented sports people may have dif- ferent expectations and wishes considering operative or con- servative treatment of an ACL rupture. Recommendation. If symptomatic instability of the knee, as a result of an anterior cruciate ligament injury, is not reduced after physiotherapy nor after adjustment of activity, anterior cruciate ligament reconstruction is recommended. This might prevent multiple interventions because of further meniscal and cartilage damage. In adults, when deciding between nonoperative or operative treatment, age should not be weighed as an important factor. In children, it may be preferable to await surgery until the growth plates are (almost) closed. An anterior cruciate ligament reconstruction should only be performed in a "quiet" knee with a normal range of motion

Dye et al (AJSM 1998) examined the consciousneurosensory mapping of the lead author's knee during arthroscopy without intraarticular anesthesia

The authors rated thelevel of conscious awareness from no sensation to severe pain. These findings were further subdivided based on the ability to accurately localize the sensation. Palpation to the anterior synovial tissues, retinaculum, fat pad and capsule produced moderate to severe pain that wasaccurately localized. The insertion sites onto the tibia andfemur of the cruciate ligaments produced poorly localized moderate to severe pain. Slight to moderate poorly localized sensation was produced at the capsular margins. No sensation was detected on the patellar articular cartilage even though asymptomatic grade II and III chondromalacia was noted on the central ridge the patella. Within the clinical setting, patients often complain of diffuse patellofemoral pain while undergoing physical examination. The results of this study may provide an explanation for the vague description of pain that is often reported by patellofemoral patients; the majority of structures palpated produced poorly localized sensation. The implications of this are interesting. It appears that degenerative changes to the patellofemoral joint, or chondromalacia, was not a source of pain. The author/subject didn't even know his patella had degenerative changes. Numerous authors (Chrisman OD: Clin North AM 1986, Dye SF: Orthop Clin North AM 1986, Fulkerson: Disorders of the Patellofemoral Joint 2004) have also documented that patellofemoral chondromalacia does not necessarily produce patellofemoral pain. Based on the results of these studies, it appears that the majority of patellofemoral symptoms may be originating from the anterior synovial tissues, retinaculum, fat pad and capsule, rather than from degeneration of the patellofemoral articular surfaces. Furthermore, several authors have also postulated that patellofemoral pain may originate in the lateral retinacular soft tissues. Fulkerson et al (Clin Orthop 1985) performed a histological analysis on lateral retinacular and underlying synovial tissue of patellofemoral patients biopsied during lateral retinacular releases. These biopsies were compared to cadaveric specimens and biopsies taken from asymptomatic, non-patellofemoral patients undergoing surgery to address anterolateral rotary instability. Nerve fibers originating in the lateral retinaculum appeared enlarged with moderate lose of myelinated fibers in the patellofemoral patient. The authors state that nerves within the retinaculum may degenerate from the chronic stretching associate with muscular imbalances around the patellofemoral joint and present as a potential source of patellofemoral pain.

A Systematic Review of the Effects of Therapeutic Taping on Patellofemoral Pain Syndrome

The contribution of hip musculature weakness on patellar malalignment has been discussed. Ireland et al11 demonstrated that hip abduction and external rotation strengths were signif- icantly less in subjects with PFPS than in healthy controls. Dysfunction of the gluteus medius muscle may induce exces- sive internal rotation at the hip. This increased internal rotation of the hip can contribute to a greater valgus force vector at the knee, thus adding to PFPS.12 Patella alta is associated with a longer patellar tendon, which may be a predisposing factor for frequent patellar sub- luxations or dislocations and can cause increased pain at the patellofemoral joint.13 The vastus medialis oblique (VMO) muscle has been suggested to act as a dynamic medial stabi- lizer, which helps to realign the patella during the last 20 to 30 of knee extension.5,14,15 Insufficiency of the VMO, in- cluding diminished VMO activity, may increase the lateral pull of the patella and reduce function at the knee joint.1,3,16,17 Physical therapy interventions for PFPS often are intended to alleviate pain by correcting or improving proper patellar tracking within the patellofemoral groove. Nonoperative man- agement includes patellar taping; stretching of the lower ex- tremity muscles, including the quadriceps, hamstrings, gas- trocnemius, anterior tibialis, iliotibial band, and gluteal muscles; stretching of tight structures such as the lateral reti- naculum; strengthening of the VMO; activity modification; biofeedback; neuromuscular electric stimulation; ultrasound; thermotherapy; bracing; and foot orthotics.5,18-21

Biomechanics of Rehabilitation Exercises

The effectiveness and safety of open kinetic chain (OKC) and closed kinetic chain (CKC) exercises have been heavily scrutinized in recent years. While CKC exercises replicate functional activities such as ascending and descending stairs, OKC exercises are often desired for isolated muscle strengthening when specific muscle weakness is present. Steinkamp et al analyzed the patellofemoral joint biomechanics during the leg press and extension exercises in 20 normal subjects. Patellofemoral joint reaction force, stress, and moments were calculated during both exercises. From 0 - 46 degrees of knee flexion, patellofemoral joint reaction force was less during the CKC leg press. Conversely, from 50 - 90 degrees of knee flexion, joint reaction forces were lower during the OKC knee extension exercise. Joint reaction forces were minimal at 90 degrees of knee flexion during the knee extension exercise. Escamilla et al observed the patellofemoral compressive forces during OKC knee extension and CKC leg press and vertical squat. Results were similar to the findings of Steinkamp et al; OKC knee extension produced significantly greater forces at angles less than 57 degrees if knee flexion while both CKC activities produced significantly greater forces at knee angles greater than 85 degrees. When analyzing the biomechanics of the OKC knee extension, remember the concept from above regarding the quadriceps force near extension. Grood et al reported that quadriceps force was greatest near full knee extension and increased with the addition of external loading. The small patellofemoral contact area observed near full extension, as previously discussed, and the increased amount of quadriceps force generated at these angles may make the patellofemoral more susceptible to injury. At a lower range of motion, the large magnitude of quadriceps is focused onto a more condensed location on the patella. My friend Rafael Escamilla has published a few new studies on patellofemoral joint forces during the lunge and squatting exercises. The first study, published in Clinical Biomechanics, demonstrated that the front and side lunge exercises showed the same pattern of force as the squatting and leg press, with more force the deeper the lunge. Interestingly, performing the lunge from a split-stance position (not actually striding to perform the lunge) also showed a decrease in force and should be used initially. His follow-up study demonstrated that a longer stride has less force than a shorter stride during the forward lunge. Escamilla also analyzed the patellofemoral joint reaction forces between the wall squat (performed with feet close to wall and far away from wall) and the single leg squat. Results indicate that the closer your feet are to the wall, the greater the force during the wall squat exercise. At deeper angles > 60 degrees, the wall squat produced greater force than the one legged squat. Interesting results that should be applied to our exercise prescription.

1. Reduce Swelling

The first principle of patellofemoral rehabilitation is the reduction of swelling. Patellofemoral patients often present with joint effusion following injury and postoperatively. Chronic edema may also exist due to repetitive microtrauma of the soft tissues surrounding the patellofemoral joint. Numerous authors have studied the effect of joint effusion on muscle inhibition. DeAndrade et al (JBJS 1965) were the first to report in the literature that joint distention resulted in quadriceps muscle inhibition. A progressive decrease in quadriceps activity was noted as the knee exhibited increased distention. Spencer et al (Archive Phys Med Rehab 1984) found a similar decrease in quadriceps activation with joint effusion. The authors reported the threshold for inhibition of the vastus medialis to be approximately 20-30ml of joint effusion and 50-60ml for the rectus femoris and vastus lateralis. This is really not a lot of fluid, so any amount of effusion is significant. An unpublished study by Bob Mangine in the 1990's showed that just a 30-40ml increase in fluid to the knee resulted in almost a 50% drop in quadriceps peak torque. The reduction in knee joint swelling is crucial to restore normal quadriceps activity. Treatment options for swelling reduction include cryotherapy, high-voltage stimulation, and joint compression through the use of a knee sleeve or compression wrap. I personally really like the Bauerfeind knee sleeves for knees that have some effusion. In patients who have undergone a lateral retinacular release, a foam wedge shaped to form around the lateral patella can be utilized in conjunction with a wrap to provide patella medialization and increased compression around the lateral genicular artery. I would not hesitate to use a knee sleeve or compression wrap to apply constant pressure while performing everyday activities in an attempt to minimize the development of further effusion

Understanding the clinical implications of the kinetic chain: The influence of the hip and foot on the patellofemoral joint

The influence of the kinetic chain on the patellofemoral can not be underestimated. Because the knee is located mid-way through a weightbearing extremity, it is vulnerable to excessive force from biomechanical faults located both proximally and distally to the knee itself. While forces from the foot and ankle have been associated with patellofemoral pain for some time now, the influence of the hip is becoming more of a hot topic as research has demonstrated significant increases in forces and injuries originating from biomechanical faults associated with the hip. A particular pioneer in this research has been Dr. Christopher Powers from the University of Southern California. A Pubmed search on Dr. Powers reveals several significant papers on the topic, specifically one of my favorites from JOSPT on the influence of the kinetic chain on patellofemoral biomechanics. I believe a significant reason why "patellofemoral pain" has been such a challenging diagnosis in the past is because we are treating the symptoms, not the cause of the pain, which is many times may be coming from elsewhere within the kinetic chain

Biomechanical Dysfunction

The knee appears to take a good amount of stress when biomechanical faults are present both proximally and distally within the kinetic chain. Alterations in foot and ankle mechanics, hip strength, leg length discrepancy, flexibility deficiencies, and any combination of these factors can have a negative impact on the forces observed at the patellofemoral joint. Not only can biomechanical dysfunction lead to increased stress, it can also lead to chronic adaptations over time. Take for example someone with weak hip external rotation. This could lead to a dynamic inability to control the hip adduction and IR moment at the knee and cause the femur to rotate into internal rotation during activities. This will cause the patella shift laterally and can cause articular cartilage and soft tissue changes that will mimic a typical ELPS patient. You can loosen up the lateral soft tissue but without treating the true cause, the hip weakness, symptoms will continue to occur. This will be discussed in greater detail in a later chapter as this is an important factor to consider.

3. Restore Volitional Muscle Control

The next principle involves reestablishing voluntary control of muscle activation. Inhibition of the quadriceps muscle is a common clinical enigma in patellofemoral patients, especially in the presence of pain and effusion during the acute phases of rehabilitation immediately following injury or surgery. Electrical muscle stimulation and biofeedback are often incorporated with therapeutic exercises to facilitate the active contraction of the quadriceps musculature. Snyder-Mackler et al (JBJS 1991) examined the effect of electrical stimulation on the quadriceps and musculature during 4 weeks of rehabilitation following ACL reconstruction. The authors noted that the addition of neuromuscular electrical stimulation to postoperative exercises resulted in stronger quadriceps and more normal gait patterns than patients exercising without electrical stimulation. Delitto et al (PT 1988) and Snyder-Mackler et al (JBJS 1995) reported similar results of both the quadriceps and hamstrings using electrical stimulation for a 3-week and 4-week, respectively, training period following ACL reconstruction. exercises such as quadriceps sets, straight leg raises, hip adduction and abduction, and knee extensions. I also use this as a maintenance program with many of my athletes with chronic knee issues.

Articulation of the Patellofemoral Joint

The patella really is an amazing bone in our body. Did you realize that the artiuclar cartilage on the undersurface of the patella is the thickest in the body? That really is amazing and shows just how much force is applied to the joint. Take a look at the picture on the right, notice how thick the cartilage is in comparison to the bone? When rehabilitating a patient with a known lesion of the patellofemoral joint, it its important to understand the joint arthrokinematics. Articulation between the inferior margin of the patella and the femur begins at approximately 10 - 20 degrees of knee flexion. The patella does not articulate with the trochlea near terminal knee extension. As the knee proceeds into greater degrees of knee flexion, the contact area of the patellofemoral joint moves proximally along the patella and posterior along the condyles. This is an important concept to understand and emphasizes the importance of good communication between the physician and rehabilitation specialist. If we know the specific area of articulation, we can work around that area, otherwise we don't know when a lesion will articulate and will have to be more conservative.

2. Reduce Pain

The second principle of patellofemoral rehabilitation is the reduction of pain. Pain may also play a role in the inhibition of muscle activity observed with joint effusion. Young et al (MSSE 1983) examined the electromyographic activity of the quadriceps in the acutely swollen and painful knee. An afferent block by local anesthesia was produced intraoperatively during medial meniscectomy. Patients in the control group reported significant pain postoperatively and pronounced inhibition of the quadriceps (30-76%). In contrast, patients with local anesthesia reported minimal pain and only mild quadriceps inhibition (5- 31%). Pain can be reduced passively through the use of cryotherapy and analgesic medication. Immediately following injury or surgery, the use of a commercial cold wrap, such as a DonJoy Iceman, can be extremely beneficial. Passive range of motion may also provide neuromodulation of pain during acute or exacerbated conditions. Various other therapeutic modalities such as ultrasound and electrical stimulation may also be used to control pain via the gate control theory if that is your belief.

What is the outcome of different non-operative treat- ment modalities? level 3

The sensation of instability is reduced for ACL-injured indi- viduals by wearing a knee brace, but initially, the use of a brace can also lead to more complaints in activities of daily living (Swirtun et al. 2005). Recommendation. It is advisable to rehabilitate patients with an anterior cruciate ligament injury using a physiotherapy exercise program that trains multiple ground-motoric abilities. We strongly recommend incorporating senso-motoric train- ing (balance and proprioception) into the rehabilitation pro- gram. It is preferable to incorporate both open- and closed-chain strength training into the rehabilitation program after an ante- rior cruciate ligament injury. There are no indications for use of a brace in the standard treatment of an ACL injury. A brace could be considered for patients with instability, who do not qualify or who do not want to qualify for operative treatment.

Strengthening

The strengthening program is begun the first day postoperative. Quadriceps isometrics, straight leg raises, and active-assisted knee extension from 90° to 30° are done 3 times a day (Table 4). Initially, straight leg raises are performed in the flexion plane only. The patient must achieve a sufficient quadriceps contraction to eliminate an extensor lag before add- ing straight leg raises in the other 3 planes (abduc- tion, adduction, and extension). These exercises are performed as 3 to 5 sets of 10 repetitions, and this set/repetition rule allows for systematic progression of ankle weights as tolerated. Weight-bearing exercises are started at weeks 3 to 4. Cup walking is done to facilitate quadriceps control during gait to prevent knee hyperextension from occurring. Toe raises for gastrocsoleus strength- ening, wall sits, and mini-squats for quadriceps strengthening are begun in patients who had menis- cus repairs. Wall sits (Figure 14) and mini-squats are delayed until 7 to 8 weeks postoperative after menis- cal transplantation. These activities should be limited from 0° to 60° of flexion to protect the posterior horn of the meniscus. Modifications to reduce patel- lar pain or increase the difficulty of wall sits have been described previously.34 Mini-squats are initially done using the patient's body weight as resistance.

Patellar Instability Tx

The treatment for patellar instability depends on the chronicity of symptoms. For acute episodes, treatment will revolve around the "damage control," or settling down the acute effusion and trauma associated with the incident. For the later phases of acute instability or those with chronic recurrent instability, we are basically dealing with a lack of "static" stability from the osseous and ligamentous structures of the knee. Thus, treatment should focus on enhancing stability in two ways: Enhance static stability. If this is an anatomical issue, this may be difficult if not impossible. This is the perfect patient for a patellofemoral brace. While a general donut knee sleeve or some of the older patellofemoral braces may be enough for some patients, there are a lot of newer and more advanced bracing. I have used the DonJoy Tru-Pull brace with success. What types of braces have you tried and preferred? Enhance dynamic stability. This is the general long term goal for these patients. It starts with enhancing strength and progresses to neuromuscular control exercises. This in itself is a lengthy topic, but I recommend you check out a DVD of the principles of neuromuscular control during knee treatment that Kevin Wilk and I have produced (more information here from AdvancedCEU). This will include dynamic stability of the entire lower extremity as any weakness in the kinetic chain could cause an excessive lateral stress on the patellofemoral joint. More to come on this in a future chapter in this eBook.

Surgical treatment— which kind of graft gives the best result in an anterior cruciate ligament reconstruction? level 2

There is no significant clinical difference between allograft and autograft ACL reconstruction in IKDC, activity scores, and stability (Carey et al. 2009, Krych et al. 2008, Sun et al. 2009). Radiating the allograft can give higher failure rates. Pre- tensioning of the allograft before the reconstruction has no additional value (Ejerhed et al. 2001, Gorschewski et al. 2005, Rappe et al. 2007, Sun et al. 2009). At short-term follow-up (2 years), there is no difference in patient-related outcome between single- and double-bundle ACL reconstruction. At short-term follow-up, there is a better recovery of the rotational stability when performing a dou- ble-bundle reconstruction (Kondo et al. 2008, Meredick et al. 2008, Seon et al. 2008, Siebold and Zantop 2008, Streich et al. 2008, Tsuda et al. 2009, Wang et al. 2009). Suturing of ACL ruptures does not lead to good results; there is an increased chance of knee osteoarthritis and many patients report knee instability and ruptures (25-30% after 5 years) (Engebretsen et al. 1989). Enhancement of the graft with, for example, a Kennedy LAD does not increase stability, diminish ruptures, or improve function, but it does lead to more side effects (swelling, infec- tion, and need for revision) (Grontvedt et al. 1995, Drogset and Grontvedt 2002, Muren et al. 2003). Use of a synthetic graft (Leeds-Keio, Gore-Tex) leads to more instability, more ruptures, more pain, and lower activity scores (Engebretsen et al. 1989, Engstrom et al. 1993, Gront- vedt et al. 1995, 1996, Drogset and Grontvedt 2002, Muren et al. 2003).

LCL tear o Pathology and MOI

This ligament is the least injured major knee ligament. LCL sprains usually occur in association with other knee ligament injuries. When torn, this ligament may heal, but in a lengthened position (slightly loose). An injury to the lateral collateral ligament of the knee can be caused by a varus stress, lateral rotation of the knee when weight-bearing or when the LCL loses it's elasticity caused by repeated stress. The LCL can be sprained (grade I), partially ruptured (grade II) or completely ruptured (grade III). Additional damage of the ACL, PCL and medial knee structures is possible when the lateral knee structures are injured

what is the management for MCL tear

Treatment of a partial tear or stretch injury is usually conservative. This includes measures to control inflammation as well as bracing. Kannus has shown good clinical results with conservative care of grade II sprains, but poor results in grade III sprains.As a result, more severe grade III and IV injuries to the MCL that lead to ongoing instability may require arthroscopic surgery. However, the medical literature considers surgery for most MCL injuries to be controversial. Since isolated MCL injuries are uncommon, surgery is often focused on ACL replacement or repair with combined surgical approaches being common.

Soft Tissue Lesions

Treatment of soft tissue lesions to the plica, IT band, fat pad, or medial patellofemoral ligament involves an understanding of the basic principles of patellofemoral pain rehabilitation, but there are a few things to consider as well. In general, you should stop the activity that is causing the irritation and avoid direct pressure on that area, so no transverse friction massage initially. This may be appropriate when chronic to stimulate healing, but in my experience this tends to make things worse for soft tissue lesions. I have found that direct anti-inflammatory modalities, such as an iontopatch, is helpful for these superficial areas of inflammation. Other treatment strategies for specific lesions include:

SURGICAL TECHNIQUES Meniscus Repair

We have previously described in detail our inside- out surgical technique for meniscus repair,52,80,81 which is similar to that originally described by Hen- ning.35,36 All knees undergo an initial comprehensive arthroscopic examination. The 70° arthroscope is used to examine posteromedial meniscal regions. The specific tear pattern, number of components of the tear, and remaining rim width are determined. Single tears occurring in 1 plane are classified as either longitudinal, radial, or horizontal. Tears with multiple components are classified as double-longitudinal, triple-longitudinal, flap, or complex multiplanar (Fig- ures 1-5). An accessory posteromedial or posterolateral inci- sion is used for suture retrieval. A popliteal retractor (Stryker Co, Kalamazoo, MI) protects the posterior structures during suture passage. The meniscus repair site and synovial junction are rasped and loose meniscus fragments removed. Multiple 2-0 coated polyester nonabsorbable sutures (Ticron; Davis and Geck Co, Wayne, NJ; or Ethibond; Ethicon Inc, Sommerville, NJ) are placed every 4 mm along the length of the tear to achieve a meticulous reduction and stabilization at the repair site. A single-barrel straight or curved arthroscopic cannula (Richard Wolf Medical, Vernon Hills, IL) is used for suture passage. The placement of sutures depends on the tear pattern. Single longitudinal tears are repaired with vertical divergent sutures, which are placed first in the superior (femoral) surface of the meniscus (Fig- ure 1). These sutures reduce the meniscus to its anatomic attachment site and ensure that the supeior surface does not displace when the cannula is later placed beneath the meniscus for the placement of inferior sutures on the tibial surface. The first pass of the suture is placed into the peripheral portion of the tear and the second pass is placed vertically through the central one-third region. The sutures are brought out through the posteromedial or posterolateral incision and tied directly over the meniscal attachment without any intervening tissues (Figure 2). The tension in each suture and meniscus tear reduction are confirmed by arthroscopic visual- ization after each suture is tied. Double- and triple-longitudinal tears require addi- tional sutures for each tear component (Figure 3). The peripheral tears are repaired first, followed by the tears in the central-third region. Vertical diver- gent sutures bridge both tear sites in the same fashion as described for single tears. Radial tears (Figure 4) and flap tears (Figure 5) are repaired with horizontal sutures placed perpendicular to the tear at 2- to 4-mm intervals. A micropick is used to penetrate the femoral notch 3 to 4 times to introduce blood into the joint in an attempt to increase fibrin clot formation at the repair site.

Lateral Meniscus Transplantation

We have previously described the techniques for medial and lateral meniscus transplantation in de- tail.63,64 Our preferred method is a central bone bridge technique, which maintains a bridge of bone between the anterior and posterior meniscal attach- ments. The meniscus bed is first prepared by remov- ing any residual meniscus tissue (leaving a 2- to 3-mm meniscus rim) and rasping the adjacent synovium. Lateral meniscus transplants contain a rectangular portion of bone from the tibial plateau, which incorporates the anterior and posterior attachments, and measures 8 to 9 mm in width and 10 mm in depth. The length of the bone attachment is usually 35 mm, but can be modified if necessary. The patient is placed in a supine position on the operating room table with a tourniquet applied with a leg holder and the table adjusted to allow 90° of knee flexion. Examination of the knee is conducted under anesthesia, followed by diagnostic arthroscopy to confirm the preoperative diagnosis and determine the condition of the articular cartilage. One 3-cm lateral arthrotomy is made just adjacent to the patellar tendon and a second 3-cm posterolateral accessory incision is created just behind the lateral collateral ligament.52,81 The lateral head of the gastrocnemius is gently dissected with Metzenbaum scissors off the posterior capsule at the joint line, followed by further dissection bluntly. The dimensions of the transplant are measured. A template is made out of aluminum foil of the transplant width and length and is placed into the lateral compartment to determine the lateralmost margin of the bone trough. A rectangular bone trough is prepared at the anterior and posterior tibia attachment sites to match the dimensions of the prepared lateral meniscus transplant. The posterior suture is tied and additional sutures are placed in a vertical fashion into the anterior one third of the meniscus, attaching it to the rim under direct visual- ization. Fixation is achieved with an absorbable inter- ference screw, which is placed medial and adjacent to the central bone attachment.24 The arthrotomy is closed and an inside-out meniscal repair is performed with multiple vertical divergent sutures, which are placed first superiorly to reduce the meniscus, and then inferiorly in the outer one-third of the trans- plant (Figure 6B) In knees that require a concomitant ACL recon- struction, an arthroscopically assisted approach is used as described previously.60 The femoral and tibial tunnels are drilled and the ACL graft is passed through the tunnels with femoral fixation done first, followed by the meniscal transplantation, and then tibial cruciate graft fixation. Accomplishing ACL graft fixation at the tibia as the final step allows for maximum separation of the tibiofemoral joint to be obtained during the meniscal transplantation proce- dure. This also prevents potential failure or problems with the ACL graft and fixation during the operation.

Clinical Implications

When applying the results of Steinkamp(38), Escamilla(39), and Grood(40), it appears that during OKC knee extension, as the contact area of the patellofemoral joint decreases the force of quadriceps pull subsequently increases, resulting in a large magnitude of patellofemoral contact stress being applied to a focal point on the patella. In contrast, during CKC exercises, the quadriceps force increases as the knee continues into flexion. However, the area of patellofemoral contact also increases as the knee flexes leading to a wider dissipation of contact stress over a larger surface area. Recently, Witvrouw et al (41) prospectively studied the efficacy of open and closed kinetic chain exercises during non-operative patellofemoral rehabilitation. 60 patients were participated in a 5-week exercise program consisting of either open or closed kinetic chain exercises. Subjective pain scores, functional ability, quadriceps and hamstring peak torque, and hamstring, quadriceps, and gastrocnemius flexibility were all recorded prior to and following rehabilitation as well as at 3 months proceeding. Both treatment groups reported a significant decrease in pain, increase in muscle strength, and increase in functional performance at 3 months following intervention. Thus it appears that the use of both open and closed kinetic chain exercises may be used to maximize outcomes for patellofemoral patients if performed within a safe range of motion. I prescribe the form of exercise based on the clinical assessment. If CKC exercises are less painful than OKC exercises, than that form of muscular training is encouraged. Additionally, in postoperative patients, regions of articular cartilage wear is carefully considered before an exercise program is designed. Most frequently, I'll allow open kinetic exercises such as knee extension from 90 - 40 degrees of knee flexion. This range of motion provides the lowest amount patellofemoral joint reaction forces while exhibiting the greatest amount of patellofemoral contact area. Closed kinetic chain exercises such as the leg press, vertical squats, lateral step-ups, and wall squats (slides) are performed initially from 0 to 30 degrees and then progressed to 0 to 60 degrees where patellofemoral joint reaction forces are lowered. As patient symptoms subside, the ranges of motion that are performed are progressed to allow greater muscle strengthening in larger ranges. Exercises are progressed based on the patient's subjective reports of symptoms and the clinical assessment of swelling, painful crepitus, and discomfort.

Sanchis-Alfonso et al (AJSM 1998) biopsied the lateral retinaculum

of patients undergoing a lateral retinacular release to address patellofemoral complaints. The authors found neuromas within the biopsied tissues similar to the results of Faulkerson et al (Clin Orthop 1985). The authors reported a direct relationship between the severity of pain and the severity of neural damage within the lateral retinaculum; patients presenting with moderate to severe complaints of pain were found to have the highest number of nerves and neural area. These findings were further supported in a follow-up study by Sanchis-Alfonso and Rosello-Sastre (AJSM 2000). The authors repeated the prior experiment, noting similar results with the additional finding of increased levels of substance P within the lateral retinaculum of patellofemoral patients. Thus, it appears that the source of pain in patellofemoral patients is multifactoral, with the surrounding soft tissues showing evidence of localized pain perception and neural adaptations that appear to contribute to the source of patellofemoral pain.


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