A 30-year-old footballer twists his knee and now cannot fully extend the leg. There is effusion, joint line tenderness medially, and forced flexion with rotation reproduces a palpable click. The knee locks at about 20 degrees short of full extension. The most likely lesion is:
- A Bucket handle tear of the medial meniscus ✓
- B Osteochondral fracture of the lateral femoral condyle
- C Synovial chondromatosis
- D Patellar tendon avulsion
Correct answer: A. Bucket handle tear of the medial meniscus
Explanation
A bucket handle tear of the medial meniscus displaces a torn central strip into the intercondylar notch, mechanically blocking extension and producing true locking with a springy block. A positive McMurray test with joint line tenderness supports it. Loose bodies cause intermittent catching rather than sustained locking, and patellar tendon injury causes extensor weakness rather than a mechanical block.
Reference: Maheshwari's Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.