Localized pigmented villonodular synovitis of the knee.

Localized pigmented villonodular synovitis (PVNS) of the knee is a rare, idiopathic condition presenting with symptoms that can be confused with various other intra-articular pathologies. The condition is usually monoarticular, the knee being most commonly affected. If totally excised, complete cure can be achieved and recurrence is very rarely reported. In this report, we present 4 cases of patients with different symptomatology but all with PVNS of the knee who underwent arthroscopic treatment. At short-term follow-up, all patients had complete recovery of their symptoms with no apparent recurrence.