Week 1-Knee Flashcards
What is a prophylactic knee brace for?
Reduce risk of injury
What is a rehabilitative knee brace for?
post-surgical
What is a functional knee brace for?
biomechanical stability
What is a patellofemoral knee brace for?
patellar tracking
Anterior pain
What is an unloader (functional OA) knee brace for?
Decrease Tibiofemoral joint compression forces
Decrease arthritic knee pain
What makes up the tibiofemoral joint?
Femoral condyles and tibial plateau
In open chain does the tibia or fibula rotate around the condyles?
Tibia rotates
In closed chain does the tibia or fibular rotate around the condyles?
Medial condyle rotates medially on tibia (locking mechanism)
Which is longer medial or lateral condyle?
medial femoral condyle
Which way is the femur angled?
medially
What is the knee capsule reinforced by?
collagen rich retinaculum
What stabilizes the knee?
Quadriceps and knee flexors
What is the menisci made of?
It is fibrocartilaginous
What does the menisci do?
Increase concavity of tibial surface Increase congruency with femoral condyles Facilitate gliding Distribute weight bearing forces Nutrition of joint
Medial collateral ligament look like what?
Flat band
What is the origin of the MCL?
Med. Epicondyle of femur
What is the Inserts of the MCL?
Med. Surface of Tibial Plateau
What does the MCL do?
Resists valgus stressors with knee slightly flexed to full extension
2nd: resist ER
Backs up ACL in anterior translation
What does the LCL look like?
Strong, flat band
What is the origin of the LCL?
Lateral femoral condyle
What is the insertion of the LCL?
Proxiaml lateral fibular head
What does the LCL do?
Resists varus stressors and lateral rotation of tibia (slight flexion)
What does the iliotibial band do?
Resists knee varus
Assists ACL to prevent posterior displacement of tibia
What does the ACL do?
Prevents anterior translation
Excessive medial rotation of tibia going into ext.
What is the origin of ACL?
Fossa joint ant. lat to ant. tibial spine
What is the insertion of the ACL?
Pos. med. surface of lat femoral condyle
When is the ACL vulnerable?
IR of tibia with flexed knee
What does the PCL do?
Resists posterior translation of tibia
What is the origin of PCL?
Posterior tibia
What is the insertion of PCL?
Pos. lat. surface of med. femoral condyle
When is the PCL tight?
Flexion
When is the PCL loose?
Extension
What does the PCL assist?
Locking mechanism
Collateral lig. with varus and valgus stressors
What the unhappy triad?
ACL
MCL
Medial Meniscus
Usually when foot planted on ground
What type of bone is the patella?
Sesamoid bone
What is the patella important to help?
knee extension mechanism
Is medial or lateral dislocation of patella more common?
Lateral
What are the osteokinematic motions of the knee?
Flexion/Extension
Abduction/Adduction
Internal/external rotation
What are the arthrokinematic movements of the knee?
Rolling
Gliding
Sliding
Which ligaments control the roll/glide of the knee?
ACL and PCL
What is the ROM knee brace used for?
Protect surgical site
What is the design aspects of the ROM knee brace?
Full extension lock
Limits ROM
Telescoping design
Full or cool design
Where is the ROM knee brace put on and how?
At hospital
Contour uprights
Place at desired ROM
or full extension if none
Who made the origianl Functional knee brace design?
Lennox Hill Derotation Brace 1970
What does the functional knee brace do?
Control ML and rotational instability when multiple ligaments impaired.
What are the design aspects of the functional knee brace?
Rigid structure
Carbon, aluminum, or titanium
Polycentric knee unit
Ext/Flex stop
When are OA knee braces used?
Collagen fibers of articular cartilage are compromised
Uneven distribution of load forces
What should be done before fitting a patient with an unloader knee brace?
Test to see if pain decreases
What are the pathologies that can benefit from the patellofemoral orthosis?
Patellofemoral pain syndrome
Patellar subluxation/dislocation
Chondromalacia
Quad or patellar tendon pain
What tests are used to test ACL?
Anterior drawer sign
Lachman Test
What test is used to test the PCL?
Posterior Drawer sign
What test is used to test MCL?
Ligament laxity
What test is used to test the LCL?
Ligament laxity
What test is used to test medial compartment pain?
Varus moment
What test is used to test lateral compartment pain?
Valgus moment
What is the anterior drawer sign?
Knee at 90 degrees
Grasp tibia compressing popliteal soft tissue
Pull anterior
What is the lachman test?
Knee at 20-30 degrees
Grasp distal thigh push posteriorly
Grasp proxiaml tibia pull anteriorly
What is the posterior drawer sign?
knee 90
Push posteriorly on pre-tibia
How do you test ligament laxity?
Knee extended and create varus (MCL) or valgus (LCL) thrust
How do you test medial compartment pain?
Patient fully weight bears
create varus moment
Increased pain is a sign for medial compartment problem (brace wont help)
Decreased pain you can use unloader brace
Which moment do you create when testing lateral compartment pain?
Valgus moment
If there is pain with a varus and valgus moment when testing compartment pain, what does it indicate?
Unloader brace is not effective
