Lateral collateral ligament complex injury

Avulsion of fibular attachment of lateral collateral ligament at the fibular head is seen with proximal retraction. Biceps femoris tendon and conjoint tendon are intact. 

Multiple other findings are seen:

• comminuted undisplaced fracture of lateral tibial condyle, extending medially into proximal shaft of tibia
• partial tears of posterolateral joint capsule including popliteomeniscal fascicles and popliteofibular ligament
• mild edema is along medial collateral ligament; its continuity is maintained
• low grade sprain of mid segment femoral attachment of anterior cruciate ligament with overall maintained continuity
• posterior cruciate ligament appears mildly lax
• complex tear of posterior horn of medial meniscus; lobulated parameniscal cyst, measuring approx. 17 x 6.5 mm is seen adjacent to it
• complex tear of anterior and posterior horns of lateral meniscus with displaced flap measuring approx. 17 x 9 mm towards lateral aspect of intercondylar notch at anterolateral aspect of tibial attachment of posterior cruciate ligament
• grade IV chondromalacia along lateral articular facet of patella, lateral trochlear facet
• near complete loss of articular cartilage along lateral tibial condyle with partial thinning and loss along lateral femoral, medial femoral and tibial condyles
• subchondral erosions along anterior periarticular aspects of both tibial condyles
• marginal osteophytes along articular aspects
• mild joint effusion, extending to suprapatellar recess