Pigmented villo-nodular synovitis and giant-cell tumor of tendon sheaths: a binational retrospective study

Pigmented villonodular synovitis is rare. Thus, we initiated a retrospective multi-center study regarding symptoms, location, type of disease, type of surgery, number of recurrences, use of adjuvant therapies and functional outcome. Ten centers contributed. Data from 173 patients were sampled. The disease was seen predominantly in joints, less frequently in tendon sheaths and bursae. Patients with articular lesions suffered mainly from the diffuse type. In tendon sheaths, the relation diffuse versus nodular was nearly 50 % each, in bursae most often the nodular type was found. Anatomically, mostly the knee was affected. Institutions with more than 20 patients had a lower rate of recurrence than those with less than 20 cases. Regarding the knee, there were less recurrences in joints treated with open synovectomy than in those treated arthroscopically. Since the rate of recurrence has been rather high, the use of adjuvant treatments (radiosynoviorthesis or radiotherapy) is recommended. In our study, the rate of their application was quite low. Patients who received an adjuvant therapy after primary surgery did not show any recurrence. In 14 % of patients in whom an adjuvant therapy had been used, after at least one recurrence, further recurrences were observed. Functional results were excellent in 84 % of patients. Prognostic multi-center study, Level III.