Localized pigmented villonodular synovitis of the knee. Arthroscopic treatment.

Localized pigmented villonodular synovitis is a lesion that may affect any joint but is frequently found in the knee. Because of its rarity, diagnostic omissions are common. Definitive treatment usually involves resection of the lesions as well as a synovectomy. Nine patients were treated arthroscopically, thereby avoiding arthrotomy. There was no evidence of recurrence at the follow-up evaluation (range, 25-108 months; mean, 48 months). The patients with mechanical knee symptoms had small nodular lesions anteriorly related to the menisci; those with degenerative symptoms had slightly more prolific nodules in other sites. No recurrence occurred in either group.