Anterior cruciate ligament deficiency and chronic medial collateral ligament rupture
Presentation
Left knee trauma one week ago, painful on knee extension.
Patient Data
Large knee joint effusion.
Horizontal tear of the body and posterior horn medial meniscus with a displaced flap overlying the posterior root attachment and intra- and para-meniscal cyst formation. Lateral meniscus is intact.
Deficient anterior cruciate ligament with patchy scar tissue along its expected course. Anterior tibial translation. Posterior cruciate ligament is intact.
Chronic proximal medial collateral ligament rupture with scarring of torn fibers onto the medial joint capsule. Lateral collateral ligament complex is intact. Small popliteus tendon sheath effusion.
Full-thickness chondral defect of the weight-bearing medial femoral condyle. Mild patellar and lateral compartment chondromalacia.
Case Discussion
Anterior cruciate ligament (ACL) deficient knees are relatively frequent with prior injury not recognized. ACL deficient knees usually have instability. Subsequent meniscal and chondral injuries are common in ACL deficient knees with the medial knee more commonly affected than the lateral knee.