Pigmented villonodular synovitis of the knee with lesions of the bursae.

Five patients with pigmented villonodular synovitis of the knee associated with lesions of the posterior periarticular bursae were treated by posterior exploration, excision of the bursal tissue, and routine anterior synovectomy of the knee. It was hypothesized that complete excision of the posterior periarticular bursae would reduce the high recurrence rate of pigmented villonodular synovitis of the knee. To completely excise the periarticular lesions, two posterior oblique skin incisions were used. In all patients, periarticular lesions were seen clearly on computed tomography scans after air arthrography and on magnetic resonance imaging scans. The patients were followed up for 6.9 years on average (range, 3.3-8.1 years) after surgery. One of five patients required reoperation because of recurrence. Two of five patients required manual mobilization after release of the intraarticular adhesion. However, in the remaining three patients, who started continuous passive motion exercise immediately after surgery, full range of motion was restored within 3 months after the operation. Complete excision of the periarticular lesions is recommended to reduce the high recurrence rate, and continuous passive motion exercise immediately after surgery also is recommended to prevent reduction of range of motion.