E1 Knee Exam
What examination steps can allow you determine an ACL injury?
+ Lachman's, + Brush test
What examination findings are common to acute meniscal tears?
+ McMurray/Apply/Thessaly, Joint line tenderness, Effusion
What are five examinations to identify a saphenous nerve entrapment?
1. Palpation for tenderness at the Hunters canal. 2. Length test of the rectus femoris 3. Isometric contraction of the rectus femoris 4. Length test of the sartorius 5. Isometric contraction of the sartorius
What incidence do females occur ACL injuries compared to males?
2 - 8 times greater
How does knee effusion affect the quads?
20 - 30mL of effusion inhibits VMO, 50 - 60mL inhibits entire Quads
What are pre-surgical principles for ACLR?
21 days plus; Restore full ROM, Increase Quad firing, Restore normal tissue homeostasis, Decrease edema/effusion
Why is the PCL often less injured?
2x the size of the ACL; typically only injured by direct blow into hyperextension of knee
MCL MOI
A valgus stress with or without a combined rotational stress to the knee most commonly causes this injury. This may be with or without contact. The foot or lower leg is usually held in a fixed position, and the upper leg and body moves or twists in relation to the lower leg. The MCL may also be injured in conjunction with tears of the ACL, PCL, and/or lateral complex
ACL MOI
ACL injury most often occurs as a result of sport related activities that place stress on the knee joint as in cutting or jumping activities, however it is not specific to sports alone. The ACL may also be injured as a result of a direct blow to the knee with the foot planted on the ground. More often, however, they are the result of a non-contact twisting injury associated with uncontrolled flexion or extension in addition to a valgus or varus stress to the knee. Regardless, the primary MOI is non-contact. It usually occurs due to the inability of the patient to control the knee when accelerating or decelerating.
What are the 2 types of Meniscus tears?
Acute and Degenerative
What is the most common demographic for ACL injury?
Adolescent female
What are the 2 types of grafts used for surgical intervention?
Allograft, Autograft
What special tests can be used to identify an ACL tear?
Anterior draw, Lachmans, lateral pivot shift; the Lachmans is the most specific and sensitive
What motions of the tibia does the ACL restrict?
Anterior translation and internal rotation
What does it mean that the meniscus provides a chop-block effect?
Assists in stability to tibiofemoral joint as well as assists in guiding movement
What is the demographic of acute meniscal tears?
Athletes and younger population
What is Petallo-Femoral Pain Syndrome?
Blanket term used to describe anterior knee pain
How is gait typically progressed?
Brace locked in extension first, Bilateral axillary crutches, WBAT
What special tests are used to assess Knee effusion?
Brush Test, Lateral indentation test
What exercises were shown to have the greatest Glute to TFL activation?
Clam, Sidestep, Quad hip extension, Sidelying hip abduction, Step-up
What is a meniscal debridement?
Clean out the roughened areas trying to maintain as much as they can but cleaning out provocative component that does not have ability to scar down
What patient complaints are common to acute tears?
Clicking/Catching/Locking
What can joint effusion lead to?
Collagen/scar tissue being laid down, Decreased ROM, Muscular inhibition
How could the Common peroneal nerve present as knee pain?
Common peroneal nerve could become entrapped at fibular head, Splits into superficial to the lateral compartment and Deep in the posterior compartment
Management of menisci
Conservative intervention has been shown to be an effective form on intervention. Effective treatment primarily consists of having an understanding of the loads that are transmitted onto and through the meniscus. In some cases surgical intervention is indicated.
Interventions for plica
Conservative therapies addressing extensor mechanism rehabilitation Massage or transverse friction massage Manage swelling Redirect compression over anterior aspect of the knee by addressing functional activities. Address muscle imbalances and patellar malalignment dysfunctions Arthroscopic excision may be required if conservative interventions fail
What is management of acute meniscal tear?
Conservative; Essentially same as degenerative but surgery may be required depending on severity of tear
What are the 3 categories following ACL reconstruction?
Copers, Adapters, Non-Copers
How does the meniscus provide transmission of force?
Cradles the tibia, therefore it gives it a greater surface area to distribute force
What are the primary surgical interventions for meniscal tear?
Debridement, Menisectomy, Meniscus repair
ITBS Interventions
Decrease the lateral stresses on the knee with massage, bracing and or taping Soft tissue manipulations of the muscles attaching to the ITB and the ITB Stretching of the associated muscle impairments Strengthening for closed chain activities Address associated dysfunctions in the hip and/or ankle
What do you want to avoid with a meniscus pathology?
Deep knee flexion exercises?
Degenerative meniscus tears
Demographic: traditionally older individuals, may be active or inactive MOI: prior history of knee injury, may be a normal part of the aging process Symptoms: pain, pressure secondary to effusion, may have clicking/catching/locking
Acute meniscus tears
Demographic: traditionally younger, active individuals MOI: weight bearing with rotation injury secondary to improper movement Symptoms: pain, clicking, catching, locking
What can lead to surgery for meniscal tear?
Depends on severity; Tear is large enough where it cannot heal itself or individual keeps stressing the tear
What can history of knee impairment/injury lead to?
Development of knee DJD/OA
What is key to managing OA of the knee?
Early PT management
How does effusion affect our examination process?
Effusion that extends knee capsule 8% is initial component of inhibiting the quads, however we cannot see effusion until capsule distends about 20%; Therefore EFFUSION IS CAUSING INHIBITION BEFORE WE CAN SEE IT OR MEASURE IT
What might you find on ACLR post-op examination?
Effusion, Edema, Ecchymosis AROM/PROM limited due to effusion/edema, Perform patellar mobs in all directions
Meniscus examination
Examination Thorough history provides information related to above Presence of effusion may or may not be present Palpation of the meniscus causing pain Special tests Apley's Compression - poor Sensitivity, ~80-90% Specificity McMurray's - ~48-65% Sensitivity, ~86-94% Specificity Thessaly's - ~66-81% Sensitivity, ~ 91-96% Specificity
Is the LCL intra or extracapsular?
Extracapsular
What is the greatest risk for re-injury?
Fatigue
PCL S/S
Findings of laxity with or without pain will follow the grades of ligamentous injury you have learned in the past. Additional signs and symptoms include: Minimal to no pain Usually full or functional range of motion (ROM) Contusion over the anterior tibia Posterior tibial sag Posterior sag sign during extension
ITBS causes
Flexion and extension the knee potentially results in the ITB moving over the lateral femoral epicondyle. During knee extension the ITB moves anterior to the epicondyle The patient may have associated history of trochanteric bursitis Leg Length Discrepancy (LLD) Adhesions of the ITB Tightness of TFL and / or Glut Max, Hams, or Quads. Genu Varum Excessive hiondfoot pronation leading to increased internal tibial rotation. Inappropriate shoe wear or running surface such as running on a slanted road. Hip Musculature imbalance
How does Patellofemoral pressure present in open chain exercises?
Forces between patella and femoral condyles is greatest as the knee is moving into extension; Force is great but over a very narrow surface area
How does patellofemoral pressure present in closed chain exercises?
Forces increase as the knee gets into further flexion - amount of force is not as much but surface area is larger
What are common Allografts?
From cadaver; Patellar tendon, Anterior Tibialis tendon, Achilles tendon
What are common Autografts?
From self; BPTB - Bone patellar-tendon bone, Hamstring tendon - semitendinosus or gracillis
What are Post-surgical principles for ACLR?
Full passive extension, Progress flexion as tolerated, Normalize patellar mobility, Decrease pain and inflammation, Gait, Voluntary Quad control, Neuromuscular Re-ed, Plyometrics
What are some considerations that may alter your progression and regression following ACLR?
Graft type, Meniscal repair, Bone bruise, Gender, Function
What is an acute on degenerative meniscal tear?
Had existing unknown degenerative meniscus and exacerbated it
Is taping effective in treating PFPS?
Has been shown to decrease pain but does not correct tracking issue. Decreases pain via stress shielding the tissue
How does the Thessaly assist in diagnosing a meniscal tear?
Has high sensitivity and high specificity
How do McMurray and Apply help in assisting diagnosis of Meniscal tear?
Have poor sensitivity but high specificity
Pittsburgh Knee Rules
High sensitivity & high specificity, but not as well validated use a series of questions to decide on the necessity of a radiograph. Those questions are as follows: First the clinician asks if there was any blunt force or trauma to the knee. If no - then no radiograph is needed. If yes - then ask if the patient is younger than the age of 12 or older than the age of 50. If yes - then a radiograph is advised. If no - then ask if the patient can walk 4 weight bearing steps in the emergency room. If yes - then no radiograph is needed. If no - then a radiograph is needed to rule out a fracture.
What do the ottawa knee fracture rules allow?
High sensitivity, if negative findings found you can rule out a fracture
What other areas of the LE must be addressed during knee examination?
Hip and ankle; Retroversion/Anteversion of the hip could lead to altered tracking of the patella
What is the Delaware criteria for determining Coper?
Hop test of affected limb within 80% or more for timed 6 meter hoop test, Knee outcome survey activities of daily living scale score of 80% or greater, Global rating of knee function 60 or greater, No more than one episode of giving way since initial injury
What are intrinsic risk factors contributing to ACL injury?
Hormonal, Posterior tibial slope, Medial tibial plateau growth, Notch size
What results from a Menisectomy?
If meniscus is removed you can already assume there are abnormal forces at the knee/hip
How will an ACL tear be treated?
Immobilization and possible surgery. Some patients may opt not to have surgery if they are not athletic or high functioning. These patients are commonly referred to as your Copers. Many surgeons prefer PT prior to surgery in an attempt to reduce the edema/effusion and allow for better outcomes of rehabiliation. There is an option with bracing before and after surgery, many surgeons are conservative with immediate bracing and others reserve bracing for high level sports, and yet other surgeons opt for no bracing. Since some of the fibers of the ACL do blend with the joint capsule, if there is any effusion present that must be treated first before attempting to increase strength.
How much force is exerted on the meniscus during closed kinetic chain movements?
In full CKC extension meniscus can receive 50% of the loads, In CKC flexion it receives 90% of the load
ACL S/S
Inability to ambulate (especially with MCL and meniscal tears) A rotational instability and a feeling of the knee "giving way." With a second degree sprain, the pain is more severe when stress tested With a third degree sprain, the pain may be less severe as no tension can be developed over the ruptured ligament. Effusion (dependent on location of tear) Minimal to significant hemarthrosis Usually incomplete functional range of motion (ROM) primarily with extension. The level of limitation will correlate with amount of effusion and / hemarthrosis.
What is an Adapter?
Individual who can get around fine but has to modify level of activity
What are other conditions that could contribute to knee pain?
Infra/Supra patellar fat pad dysfunction, Popliteus tendinopathy, Pes Anserine tendinopathy, IT band friction syndrome, Plica syndrome
ITBS S/S
Involves localized lateral knee pain ~ 2cm above joint line over the condyle when the knee is in 30º flexion, or may present as diffuse "deep" anterior knee pain Pain may radiate down toward proximal tibia. Pain becomes increasingly severe with continued activity. Tenderness over the lateral epicondyle, Gerdy's tubercle, and lateral retinaculum Positive Noble's Compression The symptoms will come on during the activity
What is found during examination of degenerative meniscal tears?
Joint line tenderness, Effusion, Less locking/catching/clicking. Same special tests
How should you manage PFPS in open chain exercises?
Keep below 45 degrees; should be in more flexion
What is scare tissue going to limit?
Knee extension
What are the best special tests to assess the following impairments? ACL
Lachmans
What is the vascular supply to the MCL?
Large vascular supply - even grade 3 sprains can go without surgical intervention
What is the relationship between the lateral and medial meniscus?
Lateral meniscus moves 2x more than medial and is thus more susceptible to injury
Why is flexion not addressed as much as extension?
Likely to cause a flare up
Meniscus functions
Load transmission -During normal activities of daily living a normal, healthy meniscus will transmit up to 70% of the load -At full knee extension the meniscus transmit 50% of the compressive locads -At 90 degrees of flexion the meniscus transmit 85% of the load Increasing joint surface contact area Assist with joint gliding Limit hyperextension Joint Nutrition Shock Absorption Chock-Block effect
How do the quads affect OA of the knee?
Loss of knee extension accelerates cartilage damage, Weak quads worsen DJD at the knee, Prolonged effusion contributes to DJD
How is full passive extension achieved early on?
Low load long duration; Goal is to match to opposite knee
Which knee ligament is considered intracapsule?
MCL as it blends with the joint capsule and medial meniscus
How is Knee OA managed?
Manual therapy, ROM, Exercise, Bracing
What is the early hip control principle in dealing with PFPS?
Maximize abduction, ER, and extension motor control, Optimize glute to TFL and Glute to hamstring ration Minimize dynamic valgus
How can the Saphenous nerve lead to problems in differential diagnosis?
May present with pain to medial knee, Located in Hunter's Canal/Adductor Canal
What are the best special tests to assess the following impairments? Meniscus
McMurrays with joint line palpation
Etiology of plica
Mimics patellofemoral or meniscal problems Plica that becomes thickened and fibrotic becomes a source of pain The tissue changes are often initiated with trauma that potentially results in synovitis and mimics other diagnoses such as meniscal tears. Pain is often intermittent and increases with activity or function
why does pain and inflammation need addressed in ACLR?
More inflammation = more pain = decrease ROM
What is the primary culprit resulting from Joint effusion?
Muscle inhibition
Muscle Imbalance as a cause of PFPS:
Muscle tightness and muscle weakness often occur together with one muscle group getting tight and the antagonist getting weak LE= weak glute med and quads Tight= hamstrings, adductors, and gastroc
What are six tissue impairments that can cause anterior knee pain?
Muscle weakness, muscle tightness, edema/effusion, tendonitis, hypermobility and hypomobility Weak hip abductors and external rotators have been shown to be a major contributor to causing increased genu valgum, adduction and internal rotation which then causes anterior knee pain. If the hip muscles are strengthened the genu valgum may resolves and the knee pain is likely to decrease. The moral of the story is to search and find the causes both above and below the location of the pain.
How does lack of active stability contribute to ACL injury?
Must have appropriately timed muscle activation - Regardless if strong enough, if not sequenced properly can still result in injury
What is the knee flexion hip extension paradox?
Must have harmonious co flexion to allow normal roll and slide at tibiofemoral joint
What are ways to increase voluntary quad control?
NMES
What are modifiable risk factors for ACL injury?
Neuromuscular control related biomechanical factors, Neuromuscular fatigue, Lack of active stability, Trunk position, Knee flexion hip extension paradox
Will ACL reconstruction guarantee full return to pre injury activity level?
No
Do knee braces enhance ACLR healing?
No have been shown to increase proprioception and decrease effusion/edema
Does an ACL injury always need surgical intervention?
No, does not always mean functional impairment and instability
How do most ACL injuries occur?
Non-Contact MOI where femur is adducted and IR creating a valgus position; Can also occur due to landing in knee extension
What is the demographic of degenerative meniscal tears?
Older usually of 50, History of knee impairment, Normal process of aging, Sometimes acute on degenerative
What types of exercises should be prescribed for patients with PFPS?
Ones that target glute met
Has bracing bene shown effective for knee OA management?
Only when it is OA on one side, Not beneficial for OA in decreasing pressure or pain
What are the best special tests to assess the following impairments? PCL
Posterior drawer
Why do you want to achieve full passive extension first?
Prevents anterior scar tissue, Allows normal arthrokinematics
What are goals of neuromuscular re-education in ACLR?
Proprioception, Anticipatory muscle firing, Dynamic muscular stabilization, Restore function, Restore confidence, Restore control when fatigued
What are the Ottawa knee fracture rules?
Pt complains of knee pain and: 1. Inability to WB immediately post MOI and/or at ED or 2. Pain with isolated touch to patella or 3. Tenderness of Fibular head or 4. Inability to flex knee past 90 or 5. If over 55 years old there is increased potential for fracture
How are Debridements managed?
Pt is likely to be able to walk the next day, however may want to limit movement for a period to allow phases of healing to ensue
What is the goal of normalizing patellar mobility?
Quad activation, Normal arthrokinematics for full ROM, Prevention of adhesions
What is a menisectomy?
Removal of entire meniscus - results in increased forces on knee and hip
What makes up Pes Anserine?
Sartorious, Gracillis, Semitendinosus
What is the old theory of PFPS?
Secondary to compression of articular surfaces - underside of patella tracking poorly and applying compression to femoral condyles
What does the Saphenous nerve provide?
Sensory only
What are the functions of the menisci?
Shock absorption, Transmission of force
What tasks are associated with females having higher ACL injury rates?
Smaller knee flexion angles, Lower glute med activity, Greater knee valgus angles, Greater hip internal rotation angles, Greater quads to hamstrings ratio
What is an example of an Adapter?
Soccer player tears ACL, can perform ADL's fine but can no longer play soccer so switches to track for sagittal plane activity only
Hypomobility as a cause of PFPS:
Soft tissue around the knee can cause a hypomobility of the patellofemoral joint. The patella will not move as much as it should which will cause anterior knee pain. A tight lateral retinaculum, tight ITB and tight quads are all potential sources of hypomobility. The impairments discussed above that cause hyper and hypomobility of the patellofemoral joint cause anterior knee pain because of increased compression of the lateral aspect of the patellofemoral joint.
What is a Coper?
Somebody that can get by without an ACL - no instability or functional impairment
What is the new theory of PFPS?
Source of pain is from soft tissue - Still related to tracking issue but tracking issue now causes compression or tension on a soft tissue; Corrected by addressed soft tissue impairment
What is a Non-coper?
Still has instability during ADL's
How is therex progressed during ACLR recovery?
Straight plane --> Multi-plane --> Rotational and diagonal Stable --> unstable Double leg --> Single leg
What is a double bundle?
Surgeon tries to mimic normal anatomy of ACL by creating anterior and posterior fibers
What is Plica Syndrome?
Synovial fold becomes entrapped in knee joint
What is the goal during plyometrics training?
Teach proper jumping/landing techniques and control/dissipation of forces
How are Meniscal repairs managed?
Tend to be non WB for up to 6 weeks to allow healing
Knee osteoarthritis
That impairment cycle of osteoarthritis is: Cartilage breakdown à Muscle weakness à Mobility impairments à Cartilage breakdown à etc.
Based on the anatomical attachments of the ACL, why might effusion not be present with a tear of the ACL?
The ACL is extra-capsular meaning that it lies outside the joint capsule, however there are some fibers in the anteriormedial aspect that do blend with the joint capsule
Common Peroneal Nerve
The common peroneal nerve is motor and sensory. It is motor to the ankle dorsiflexors and evertors and sensory to the distal lateral leg and dorsum of the foot. Impairment to the common peroneal nerve can be a result of direct trauma to the area (i.e. fracture) or pressure from a cast or brace/boot. In addition, a patient that experiences a lateral ankle sprain (inversion and plantar flexion) is susceptible to tensioning of the nerve which can cause damage. Remember the common peroneal nerve splits into the superficial peroneal nerve and the deep peroneal nerve. QUESTION: Can you recall the sensory and/or motor innervations of these two branches? Treatment of the common peroneal nerve is like that for all other nerve entrapments. That being, relieve the source of pressure or decrease the tension on the nerve.
Why do not use the terms tendonitis or tendonOSIS in E1? What are the new terms we use to replace these?
The specific findings for the diagnosis of a tendinopathy will include positive MSTTs, positive muscle length tests, and positive palpation for tenderness. Keep in mind, PFT must be conducted along the length of the entire tendon. In the example of the patellar tendon, PFT should be formed at the inferior pole of the patella, the tendon itself and/or the tibial tuberosity.
What special test identifies a plica problem? Is this a good test or bad?
The stutter test will identify a plica, however look in Magee at how the test is performed what other impairments can cause the knee to stutter? Swelling, tight hamstrings, hypomobility, hypermobility, ligament instability, muscle weakness to name a few
How would you incorporate the biomechanics of the patellofemoral joint you learned in Unit 3 within your treatment?
There are some classic symptoms that are associated with PFS. These include anterior knee pain, pain with sitting, pain with descending stairs and a gradual onset of pain. Before we start discussing PFS and its causes, let's talk about Chondromalacia. Chondromalacia is just what the two parts of the word indicate - softening of the cartilage. It too is often overused as a diagnosis. It can cause anterior knee pain and may be diagnosed as PFS rather than the medical diagnosis of chondromalacia.
Hypermobility as a cause of PFPS:
There are three main structural impairments that will result in a hypermobility of the patellofemoral joint. These include genu valgum which will cause increased lateral mobility of the patella as well as increasing the Q angle. A small lateral femoral condyle will also increase lateral movement of the patella. As will patella alta. These three structures will cause the patella to "track" or move more laterally which will result in anterior knee pain.
Why is patellofemoral syndrome not a tissue specific impairment?
There is not specific tissue or impairment identified; there are several different impairments and tissues that can be labeled as PFS
Is manual therapy and exercise effective for patients with knee OA?
They have been effective in prolonging the progression of OA and can prolong the need for surgical intervention
How can the diagnosis of chondromalacia be confirmed?
Through radiograph or arthroscope; there are no clinical tests that will confirm this diagnosis
What results if harmonious hip and knee flexion is not present?
Tibia will anterior translate with sole restriction being ACL
The knee is composed of three joint articulations. Those are:
Tibio-femoral joint Patella-femoral joint Proximal tibio-fibular joint
Why must the lateral meniscus have more movement?
To assist with locking mechanism during knee flexion/extension
What is a meniscal repair?
Trying to restore everything that's there and bring it back to prior function
What are some extrinsic risk factors contributing to ACL injury?
Type of competition, Shoe/Surface interface, Knee bracing, Weather
LCL
Unlike the MCL, the LCL plays a primary role of resisting a varus force to the knee. Injury to the LCL is less common than damage to the MCL. The LCL is not the only tissue that resists against a varus load.
How should you manage PFPS in closed chain exercises?
Want to work 0 - 45 degrees as going deeper into flexion increases amount of surface area receiving compression
S/S of MCL Injury
With a first degree sprain there will be pain at the site of the damage with touch Stressing the ligament with a valgus force (when the knee is slightly bent and the shin is moved out in relation to the thigh) is painful In the case of a second degree sprain, the pain is more severe when touched and when the ligament is stressed There will usually be a swelling of the knee joint, but this may take 24 hours to appear In the case of a third degree sprain, where the ligament is ruptured, the pain is excruciating initially. With this injury the knee joint is unstable and activity cannot be continued There will be a bleed and an inflow of fluid into the joint
Can the meniscus heal?
Yes but must understand the loads that can be applied
What do you think the Chock-block effect of the meniscus is?
You are already familiar that the meniscus are held firmly in place to the tibia by way of the coronary ligaments, but did you know the meniscus still move on top of the tibial plateau? In fact, the lateral meniscus has been shown to have as much as ~12mm of translation, while the medial meniscus has been shown to have only ~6mm of translation. Coincidentally enough the medial meniscus becomes injured more often than the lateral meniscus. Perhaps this is due to the fact the meniscus move less and are unable to move "out of the way".
Pain and PFPS
associated with PFPS is attributed to the surrounding soft tissues of the knee. Any of those soft tissues. This pain is secondary to poor tracking of the patella, poor muscular balances, poor muscular activation, and/or poor kinetic chain positioning and functioning. When it comes to rehabilitation of PFPS you must identify the cause by examining the entire kinetic chain of the LE. Generally speaking, there are 10 key principles of PFPS rehabilitation. Those are: Reduce swelling Reduce pain Restore volitional muscle control Emphasize quadriceps strengthening Control the knee through the hip, and the ankle/foot Enhance soft tissue flexibility Improve soft tissue mobility Enhance proprioception and neuromuscular control Normalize gait Gradually progress back to activities
Patellofemoral pain syndrome (PFPS) and tendonitis
by using the term PFPS you are simply stating the patient has pain within the anterior aspect of their knee. It does not define what is causing the pain or where the pain specifically is.
ACL
composed of 2 portions, the anteromedial and posterolateral bands. During flexion the anterior band is taut while the posterior is loose; during extension, the posterolateral band is taut, while the anterior band is loose. This directly coincides with the fact that the anteromedial bundle is primarily injured with uncontrolled flexion, while the posterolateral bundle is primarily injured with uncontrolled extension.
How can the dysfunction of excessive rearfoot supination cause ITB friction syndrome?
excessive supination will cause tibial ER which will alter the relative position of the distal attachment of the ITB placing abnormal stress on it
LCL MOI
he LCL may be damaged in collision sports, such as when an opponent applies a force to the inside aspect of the leg just below the knee. This typically occurs when the foot is planted on the ground.
S/S of LCL Injury
include: With a first degree sprain there will be pain with palpation Stressing the ligament with a varus force is painful In the case of a second degree sprain, the pain is more severe when the injury site is touched and when the ligament is stressed. Because the ligament is outside the knee joint, there may not be marked swelling of the knee. In the case of a third degree sprain, where the ligament is ruptured, the pain is not as intense after the initial injury and the knee joint becomes unstable.
Plica
knee is an excesses synovial fold that is not reabsorbed with development growth. The most commonly involved plica is medial patellar plica. The signs and symptoms can be consistent with other diagnoses and be a significant source of anterior knee pain especially with knee flexion activities. Plicae occur secondary to injury or overuse. An otherwise normal structure, once an inflammatory process is established, the normal plica may hypertrophy and become fibrotic. The fibrotic plica potentially becomes a pathological structure. The presence of an inflamed plica has been implicated as a cause of anterior knee pain.
What are the best special tests to assess the following impairments? MCL and LCL
no randomized controlled trials to evaluate the sensitivity and specificity of valgus & varus stress tests
Knee joint capsule
primarily encompasses the tibio-femoral and patella-femoral joints The capsule of the knee has a posterior invagination which is where the cruciate ligaments are located. This results in the ACL and PCL being considered extra-capsular yet still intra-articular. That being said, the ACL does have fibers that blend with the joint capsule along the anterior medial aspect at its insertion onto the tibia.
PCL
primary role of preventing posterior tibial translation. Injuries to the PCL are not as common as the other ligaments, particularly in comparison to the ACL. The reason is due to the fact that the PCL is 2x the size of the ACL and that a posterior translator force on the tibia is not very common.
Iliotibial band syndrome (ITBS)
result of irritation to the distal portion of the ITBand as it compresses and rubs against the lateral femoral epicondyle. This is an overuse injury that occurs with repetitive flexion and extension of the knee. Irritation may also occur secondary to a lack of flexibility and/or strength of the quadriceps/hamstrings. During knee extension the ITB moves anterior to the epicondyle
Saphenous nerve
s only sensory. It is the longest sensory branch that comes off the femoral nerve at the location of the femoral triangle. As it descends along the medial aspect of the thigh it enters the Adductor canal (aka Hunter's canal). The adductor canal is a tunnel that is made up of the sartorius (anterior aspect of the canal), adductor magnus (posterior-medial aspect of the canal), and the vastus medialis (lateral aspect of the canal). The saphenous nerve provides sensation to the anteromedial aspect of the knee and lower leg, and provides some sensory contribution to the knee joint. It is susceptible to entrapment at the location of the adductor canal, therefore it is important to thoroughly examine all tissues related to this canal in patients with complaints of medial knee pain. This is particularly important when a primary impairment at the knee joint cannot be identified.
PCL MOI
secondary to an outside force by way of direct contact to the tibia forcing it posteriorly, such as falling on a flexed knee or a dashboard injury from a motor vehicle accident.
MCL
superficial aspect of the MCL has demonstrated to restrain valgus loads at all degrees of knee flexion and acts as a primary restraint to external rotation of the tibia
Effusion
there is a loss of muscular activation in the presence of knee joint effusion. This loss of muscular activation has been shown to be most specific to the quadriceps. A study by Spencer et al. revealed the following: Onset of 20-30mL of effusion - inhibition of the vastus medialis Onset of 50-60 mL of effusion - inhibition of the entire quadriceps But how do we measure mL of swelling in the knee? We can't. Interestingly enough, additional research has measured the total capacity of the knee joint to sustain fluid. They found the following: At 10-20% of distention is when the amount of effusion first becomes visible to the naked eye At 5% of distention quadriceps inhibition is noted QUESTION: What does the above information tell you? It states that quadriceps inhibition may be occurring prior to our ability to see, or perhaps even measure, the presence of effusion.
