MSK 2: Knee
Laxity in what position of the Valgus Stress test would indicate a major disruption?
*Blue question 0 and 30 degrees of flex
Knowing the amount of loads transmitted through the meniscus at the varying ranges of knee motion, what would be your recommendation regarding weight bearing activities for a patient with a meniscus tear?
*Blue question do not bend knee beyond 90 degrees of flexion
Do you recall what chondromalacia is from Ortho?
*blue question "runner's knee," --> cartilage on the undersurface of the patella softens. This causes knee pain and can be mistaken as PFPS
If joint alignment was not corrected, the PCL may cause false positive findings during what special test?
*blue question --> anterior drawer? because if the tibia is sagging posterior then there will be more room to pull the tibia forward
What motions of the tibia does the ACL restrict?
*blue question -Anterior translation -Tibial IR
Under what situations would you chose to conduct one of the meniscus special tests and not the others?
*blue question -Do not do thessaly's with someone who has poor balance or is NWB
Muscle tightness and muscle weakness often occur together with one muscle group getting tight and the antagonist getting weak. In the LE, what muscles typically get tight?
*blue question -Hamstrings -Adductors -Gastrocs
Muscle tightness and muscle weakness often occur together with one muscle group getting tight and the antagonist getting weak. In the LE what muscles typically get weak?
*blue question -glute med -quads
At what degrees of knee ROM should you perform strengthening in the presence of a patellofemoral pathology?
*blue question OKC: 45-90 degrees of knee flexion CKC: 0-45 degrees of knee flexion
What is the difference between the meniscus transmitting loads versus acting as shock absorption?
*blue question Transmitting loads ensures that the tibia and the femur never come into contact with each other; spreads out force throughout a higher surface area Shock absorption: the cartilage will cushion (in Viti's notes he says meniscus doesn't even have this role so)
What do you think the Chock-block effect of the meniscus is?
*blue question when the knee is moving into flexion, the menisci prevent the femoral condyles rolling off the back of the tibial surface
Based on the anatomical attachments of the ACL, why might effusion not be present with a tear of the ACL?
*blue question it is extra-capsular anteromedial tibial plateau --> posteromedial lateral femoral condyle
Would you be able to name (10) causes of compression of the lateral patellofemoral articulation?
*blue question 1. tight quads 2. weak quads 3. Patella alta 4. Genu valgum of the knee 5. Weak posterior tibialis .6. Tight peroneals 7. Tightness of lateral retinaculum 8. Tight IT band 9. Small lateral femoral condyle 10. Weak hip ER
How would you incorporate the biomechanics of the patellofemoral joint you learned in Unit 3 within your treatment?
*blue question OKC Exercises - being initially within ranges of 90-45 flex and progress from there in ROM CKC Exercises - begin initially within the ranges of 0-45 flex and progress from there in ROM
Based on the above special tests, which one would you rely on to rule in a meniscus tear? Which one would you rely on to rule out a meniscus tear?
*blue question Based on the spec/sens in BB, In: Thessaly's - 91-96% Specificity Out: Thessaly's - ~66-81% Sensitivity
Identify tissues that could be a source of PFPS and how to treat:
*blue question kinda -tight IT band (stretch) -quadriceps (stretch) -weak hip ABD and ER (strengthen) -small lateral femoral condyle
Typical MOI for MCL:
-A valgus stress with or without a combined rotational stress to the knee (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
Based on Sensitivity and Specificity, what are the best special tests to assess the following impairments?
-ACL (Lachman's) -PCL (posterior drawer) -Meniscus (McMurray's with joint line palpation) -MCL & LCL (valgus and varus)
What are the 3 special tests used to find meniscus pathology?
-Apley's Compression (poor sensitivity) -McMurray's Thessaly's
At 0 and 30 degrees of knee flexion, there is more resisting valgus than just the MCL. What other tissues help resist valgus?
-Posterior oblique ligament -Posterior medial joint capsule -ACL -PCL -Medial quadriceps expansion -Semimembranosus
LCL is not the only tissue that resists against varus load at 0 and 30 degrees of flexion. What other tissues resist?
-Posterolateral capsule -Arcuate-popliteus complex biceps femoris tendon -ACL -PCL -Lateral gastrocnemius muscle -ITBand
10 key principles of patellofemoral pain syndrome rehab:
-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
MOI for PCL injury:
-Secondary to an outside force by way of direct contact to the tibia forcing it posterior ex: fall on flexed knee or. dashboard injury
What can cause hypomobility around the patellofemoral joint?
-Soft tissue (lateral retinaculum, ITB, quads) -This can lead to anterior knee pain
What special tests can be used to identify an ACL tear?
-Stable Lochman -Anterior drawer -Lateral pivot shift
In patellofemoral syndrome, what is the pain attributed to?
-Surrounding soft tissues of the knee (any) -Pain is secondary to poor tracking of the patella, poor muscular balance, poor muscle activation, poor kinetic chain positioning/functioning
The joint capsule of the knee primarily encompasses what 2 joints of the knee?
-Tibio-femoral -Patella-femoral
What are the classic symptoms associated with patellofemoral pain syndrome?
-anterior knee pain -pain with sitting -pain with descending stairs -gradual onset of pain
MOI of ACL pathology:
-cutting or jumping -Direct blow to the knee with foot planted on the ground -MOST COMMON: non-contact twisting injury associated with uncontrolled flex or extension with valgus or varus stress -usually occurs due to inability to control knee during accerelation or deceleration
3rd degree MCL sprain:
-pain is excruciating initially -upon direct examination, laxity felt but no pain -knee unstable and activity cannot be continued -there will be a bleed and inflow into the joint
2nd degree MCL sprain:
-pain more severe when touched and the presence of laxity when ligament is stretched -swelling of knee, may take 24 hours to appear
At what degree of knee flexion does the patella contact the femur?
20 degrees of flexion --> Both medial and lateral facets of the INFERIOR pole are in contact
What ligament of the knee resists varus forces and is less likely to be damaged than the MCL?
LCL
The menisci move on top of the tibial plateau. Does the medial or lateral meniscus move more?
Lateral (11-12mm) compared to medial (5-6mm)- is this why medial is injured more often?? maybe
The greater the surface area of the contact, the better the load distribution across that surface area.
Think about this in terms of the patella being in contact with the femur during knee flexion--> this should be a reasoning behind what exercises you choose in treatment
How can the diagnosis of chondromalacia be confirmed?
Through radiograph or arthroscope; there are no clinical tests that will confirm this diagnosis
At what percent of distention is effusion visible to the naked eye? At what percent is the quadriceps inhibited?
To the eye: 10-20% Quad inhibition: 5% --> This tells us that prior to seeing the effusion we will note inhibition of the quads
The Pittsburgh Knee rules have the patient answer a series of questions. What is the first question:
Was there any blunt force trauma to the knee?
MOI for acute meniscus tears
Weight bearing with rotation injury secondary to improper movement -Traditionally younger, active individuals -Sx: pain, clicking, catching, locking
In the Pittsburgh Knee Rules if the patient has suffered from blunt force trauma to the knee and is under the age of 12 or older than 50, is a radiograph needed?
YES
In the Pittsburgh Knee Rules if the patient has suffered from blunt force trauma to the knee and is NOT under the age of 12 or older than 50, is a radiograph needed?
a radiograph may not be needed to rule out a fracture --> sounds like we should still do the x-ray to be sure
The Ottawa Knee Rules are used as?
a screening tool for fractures around the knee
Patellofemoral pain syndrome is simply stating that the patient has pain within the ____ aspect of the knee.
anterior --> this is an umbrella term
In an ACL injury with uncontrolled FLEXION, which band is more commonly injured?
anteromedial (because this band is taut during flexion)
Is the knee joint considered uni-condylar or bi-condylar?
bi-condylar
____ kinetic chain - knee flexion - load increases by way of quadriceps pull
closed --> contact area increases à large distribution of forces through a larger surface area
___ kinetic chain - knee extension - load increases by way of quadriceps pull
open --> contact area decreases à large distribution of forces through one focal area
In regards to ACL injury, what are "your copers"?
those who opt out of surgery if they are not athletic or high functioning
1st degree LCL sprain:
-Pain with palpation -Stressing the ligament with varus is painful -No laxity present
1st degree MCL sprain:
-Pain with touch -Stressing the ligament with valgus force is painful (No laxity)
3rd degree LCL sprain:
-Painful MOI -Laxity present -Pain does not increase with laxity testing
Management of meniscus tear
-Conservative treatment is effective: understand loads that are transmitted onto the meniscus -Pt may need surgery
MOI of LCL injury:
-Damaged in collision sports -Force applied to the inside aspect of the leg just below the knee, typically when the foot is planted
A knee X-ray is needed if the patient reports pain in the knee and...
-Patient is older than 55 years old OR -Tenderness at the head of the fibula -Isolated tenderness of the patella OR Inability to flex to 90 degrees OR -Inability to weight-bear
Signs and symptoms of PCL tear:
-Findings of laxity with or without pain -Usually full or functional ROM -Contusion over the anterior tibia -Posterior tibial sag -Posterior sag sign during extension
What are the 3 main structural impairments that will result in hypermobility of the patellofemoral joint?
-Genu valgum -small lateral femoral condyle -patella alta (high riding)
What are the clinical implications the hip and ankle/foot have on the influence of the patellofemoral joint?
-Hip anteversion can lead to a valgus which can increase compression on the lateral side of knee and increase tension on medial knee (and retroversion causing varus) -Ankle/foot supination or pronation can affect knee alignment
How will an ACL tear be treated?
-Immobilization and possible surgery -PT prior to surgery to reduce edema/effusion -Bracing before or after surgery
Signs and symptoms of ACL tear:
-Inability to ambulate -Rotational instability (knee giving way) -Effusion -Minimal to significant hemarthrosis -Usually incomplete functional ROM with extension (dirrectly correlates with effusion and hemarthrosis)
What are the functions of the meniscus?
-Load transmission (increases surface contact area) -Assist with joint gliding -Limits hyperextension -Joint nutrition -Shock Absorption -Chock-block effect
2nd degree LCL sprain:
-Pain more severe with palpation and when stressed -Laxity noted
What are the 3 joint articulations of the knee?
1. Tibio-femoral 2. Patella-femoral 3. Proximal tibio-fibular
What are the 3 joints of the knee?
1. Tibiofemoral 2. Patellofemoral 3. Proximal tibiofibular
What are the component motions at the tibiofemoral joint that would improve knee extension?
1. Distraction 2. Anterior glide 3. Posterior glide at lateral condyle of tibia 4. Posterior glide of FEMUR 5. Anterior glide at medial condyle of tibia
What are the component motions at the patellofemoral joint that would improve knee extension?
1. Superior glide 2. Medial/Lateral glide 3. Medial/Lateral tilt 4. Inferior/Superior tilt (they all improve flex and ext)
How many component motions are there that would improve knee extension?
1. Superior glide patella 2. Medial glide patella 3. Lateral glide patella 4. Lateral tilt patella 5. Medial tilt patella 6. Distraction of tibia femoral joint 7. Anterior glide of tibia femoral joint 8. Posterior glide at lateral condyle of tibia femoral joint 9. Posterior glide of femur on tibial femoral joint 10. Anterior glide of medial tibia condyle
At what degree of knee flexion is the middle of the patella in contact with the femur but the odd facet is usually spared from contact?
45 degrees
What degree of knee flexion is the middle of the patella in contact with the femur along with the medial and lateral sides?
45 degrees of flexion
During normal activities of living, a healthy meniscus will transmit up to what percent of load?
70% -At full extension it transmits 50% -At 90 degrees flexion the meniscus transmits 85% of the load
Beyond ___ degrees of flexion the contact of the patella shifts from the superior 1/3 of the patella to the inferior and lateral aspects of the patella.
90 --> This now applies a load on to the odd and lateral facets of the knee
At what degree of knee flexion does the superior 1/3 of the patella become the primary area of contact with the femur?
90 degrees --> this includes the medial and lateral sides, odd facet usually spared
In knee (flexion/extension) is when the meniscus transmits the most percentage of load?
90 degrees flexion (85%) -remember that in full extension it transmits only 50%
What component motion technique is useful in restoring the knee flexion beyond 100-120 degrees?
Anterior tilt of the tibia --> as the knee gets closer to this range of flexion the posterior glide of the tibia ceases and the anterior tilt begins
There are 2 bands of the ACL: anteromedial and posterolateral. During EXTENSION, which is taut and loose?
Anteromedial band LOOSE Posterolateral band TAUT
There are 2 bands of the ACL: anteromedial and posterolateral. During FLEXION, which is taut and loose?
Anteromedial band TAUT Posterolateral band LOOSE
Why is it common for effusion of the knee capsule to be mistaken as edema?
Because many clinicians do not realize how proximally up the femur and how distally down the tibia the knee joint capsule is
Where is the joint capsule of the knee located, specifically?
From the lower margin of the patella above, to the infrapatellar synovial fold below --> thickened laterally by the collateral ligaments
What are all the joint plays that would have an effect on improving classical motions at the knee?
Glides of the fibular head joint: -Posterior-Medial -Anteiror-Lateral
What PCL special test is when the practitioner observes for posterior sag of tibia?
Godfrey's
If the knee is in genu valgus, in what position is the femur?
IR
If the patient answers "yes" when asked if there was any blunt force trauma to the knee, then what do you ask?
Is the pateint younger than 12 or older than 50?
If the patient answers "No" when asked if there was any blunt force trauma to the knee, is an x-ray needed?
no
What are six tissue impairments that can cause anterior knee pain?
Muscle weakness, muscle tightness, edema/effusion, tendonitis, hypermobility and hypomobility
Why do not use the terms tendonITIS or tendonOSIS in E1? What are the new terms we use to replace these?
New research has been undertaken and backed that NO inflammatory processes are occurring within tendon tissue. Therefore, an -itis (inflammation of) is a false description of the pathology. INSTEAD, the new research suggests a continuum of tendinopathy including : reactive tendinopathy(acute), tendon dysrepair (subacute), and/or degenerative tendinopathy (chronic).
Prevention of posterior translation is the job of what ligament?
PCL --> PCL injury not as common as ACL because it is 2x as large and posterior tibial force is not very common
The Pittsburgh Knee Rules are similar to Ottawa Knee Rules except for the fact that...
Pittsburgh Knee Rules have not been validated as well as the Ottawa Ankle Rules
MOI for degenerative meniscus tears
Prior history of knee injury, may be a normal part of the aging process -older individuals -Sx: pain, pressure secondary to effusion, may have catching/clicking/locking
What ligament plays a role in restraining valgus loads at all degrees of knee flexion and acts as a primary restrain to tibial ER?
medial collateral ligament
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
1. Symptoms of clicking/locking within the knee 2. Joint line tenderness with palpation 3. Pain with knee flexion 4. Pain with knee hyperextension 5. Positive McMurray's special test
These are cluster findings for meniscus --> if 3 sx are present, specificity is 90% --> if 4 sx are present, specificity is 96% --> if 5 sx are present the specificity is 99%
Loading by the way of the quadriceps is the greatest as the knee is moving towards terminal knee ____ in ____ kinetic chain
extension open --> this is due to the fact that the amount of surface area of the patella contacting the femur is the smallest toward knee extension
Who is more susceptible to ACL injuries, males or females?
females
As knee flexion increases, the amount of contact between the patella and femur begins to (increase/decrease)
increase --> As the knee flexes to 90 degrees the contact area triples
During closed kinetic chain, the contraction of the quadriceps and the load it applies on the patella into the femur ___ as the knee goes into flexion
increases
Research shows that in the presence of a knee joint effusion there is a loss of _____ _____
muscle activation (Quads) --> 20-30mL inhibits vastus medialis --> 50-60mL inhibits all quads
What joint in the knee complex is often considered to be one of the primary knee complaints seen by PT?
patellofemoral joint
In an ACL injury with uncontrolled EXTENSION, which band is more commonly injured?
posterolateral (because this band is taut during extension)
If the knee is in genu valgus, in what position are the hindfoot and ankle joint?
pronation
One of the roles of the ____ muscle is to load the patellofemoral joint and assist in stabilizing it.
quadriceps
The Ottawa Knee Rules have a high (sensitivity/specificity)
sensitivity --> useful for ruling OUT a fracture
