Background: Pigmented villonodular synovitis of the hip is a rare disease. Synovectomy is generally accepted as the only surgical treatment for the disorder, but there have been few studies with a sufficient sample size and duration of follow-up to allow the evaluation of long-term outcomes. The aim of this study was to determine the long-term outcome of the treatment in sixteen patients.
Methods: Sixteen patients (nine men and seven women), with a mean age of 35.5 years at the time of surgery, were treated between 1970 and 1996. Complete synovectomy was performed in all patients; in addition, three had a cup arthroplasty, four had a total hip arthroplasty, and one had a monopolar arthroplasty. Clinical and radiographic outcomes were evaluated retrospectively at a mean of 16.7 years postoperatively. Only one patient was followed for less than eight years.
Results: Nine patients needed repeat surgery, but only one had recurrent synovitis, as detected with pathological examination fourteen years after treatment with synovectomy and cup arthroplasty. Secondary osteoarthritis developed in all eight patients who had been treated with synovectomy alone, and four of them required a total hip arthroplasty within the follow-up period.
Conclusions: These results support earlier data indicating that osteoarthritis consistently develops in patients with pigmented villonodular synovitis of the hip. Complete synovectomy seems to be effective in preventing recurrence of the synovitis, but it does not appear to prevent the development of secondary osteoarthritis.