Knee anatomy Flashcards
Anterior cruciate ligament
lateral femoral condyle to anterior tibia
Resists anterior movement of tibia
Posterior cruciate ligament
Medial femoral condyle to posterior tibia
Posterior cruciate ligament begins where and ends at the posterior tibia
Medial femoral condyle
ACL or PCL, which begins at lateral femoral condyle?
ACL
Resists valgus and varus deformity
Collateral ligaments
MCL/LCL, which ends on head of fibula?
Lateral collateral ligament
Tests for ACL injury
Anterior drawers sign and Lachman’s test
Test for PCL injury
Posterior drawer sign
Middle genicular artery
ACL’s main blood supply
Lateral meniscus tear
present with positive lateral joint line tenderness on physical exam.
Occurs in over half of acute ACL tears
Main structure to resist varus stress
Lateral collateral ligament
Damaged with a direct blow to medial aspect of knee
LCL
Shock absorbers between femur and tibia
menisci.
Also help distribute weight bearing forces, and act as stabilizers between femur and tibia
Dashboard accident suggests?
PCL injury
originates from the lateral border of the distal femoral condyle and inserts onto the anterolateral aspect of the proximal fibula
LCL
Originates from the inferior pole of the patella and inserts onto the tibial tubercle
Patellar tendon
Main action is to extend the tibia
Patella’s main function is to aid with knee extension.
T/F?
True
How is the ACL most commonly injured?
Via non contact pivoting mechanism
Patellar fracture vs ACL injury
Both present with knee effusions and decreased knee range of motion.
ACL tear: Can extend knee and maintain passive knee extension. Patellar fracture can’t. Positive anterior drawer and Lachman’s test unlike patellar fracture
What structure is most commonly injured from trauma where a posteriorly directed force is applied to the tibia
Posterior cruciate ligament
Physical exam of MCL injury will show..?
increased medial joint space widening with a valgus applied force to the knee
Valgus vs varus
Valgus: Knock knee, knee points inward. MCL resists this
Varus: Bowleg, knee points outward, LCL resists this
Test for diagnosis of meniscal injuries
McMurray test, Thesally test
Medial meniscus injury would cause pain upon valgus stress (but no joint space widening) T/F?
True
