A 25-year-old man experiences pain in the right knee following fall. His knee is swollen. He cannot bear full weight or fully extend his leg. There is tenderness over the medial joint line. X-ray findings were normal, and the range of motion (ROM), although restricted, is stable to varus and valgus stress. Straight-leg raise is unrestricted. Which is the most likely type of injury?

Restriction of motion ("locking"), effusion ("swelling"), and medial joint-line tenderness are the hallmarks of meniscal tears.Stability-to stress testing eliminates collateral ligament rupture, and the ability to elevate the straight leg eliminates patella dislocation and quadriceps tendon ruptures.In addition, patella dislocation would also be characterized by gross patella deformity laterally.