An unusual case of pigmented villonodular synovitis after total knee arthroplasty presenting with recurrent hemarthrosis.

Pigmented villonodular synovitis (PVNS) is a benign proliferative joint disease, which is a rare finding after total knee arthroplasty (TKA). There is currently no link between PVNS and TKA, and it has been described infrequently in the literature. Its presentation has varied along with the time that it presents postoperatively. We describe a case of a patient who presents with recurrent hemarthrosis 4 years after TKA. The patient had no previous history of PVNS and had an arthroscopy 1 year after the index operation with no evidence of synovitis. We present details of the first case with a review of imaging and pathology and a brief review of the literature on PVNS occurring after TKA.