Snapping Knee Syndrome of the Sartorius Accompanying Osteoarthritis Cured by Osteophyte Removal During Total Knee Arthroplasty.

Snapping knee syndrome on the medial side is rare. Here, we report the case of a patient with snapping knee syndrome of the sartorius with knee osteoarthritis. A large osteophyte at the posteromedial femoral condyle impinged on the sartorius myotendinous junction, causing painless snapping. The patient was successfully treated with osteophyte removal and total knee arthroplasty while preserving the tendon. Hence, tendon release or resection to treat snapping syndrome is not always necessary if the underlying cause can be eliminated. Furthermore, we found that while tendon tension is important for the occurrence of snapping syndrome, the impingement site determines the occurrence of snapping pain.