Results and recurrence of pigmented villonodular synovitis of the ankle: does diffuse PVNS with extra-articular extension tend to recur more often?

PURPOSE: The aim of this study was to provide the outcomes and to analyze the recurrence of Pigmented Villonodular Synovitis (PVNS) of the ankle joint treated by surgical synovectomy.

METHODS: Thirty-one PVNS cases of the ankle, including 5 localized PVNS cases and 26 diffuse PVNS cases, were treated in our institute between 2004 and 2015. The median age was 35 (range 18-63) years. The 5 localized PVNS cases were treated with partial synovectomy (group I); 10 diffuse PVNS cases limited to intra-articular synovium received arthroscopic comprehensive synovectomy (group II); and 16 cases with diffuse PVNS spreading to extra-articular tendon sheaths underwent combined arthroscopic and open synovectomy (group III). Adjuvant radiotherapy was provided in groups II and III. The American Orthopaedic Foot and Ankle Society (AOFAS) score and subjective grading of procedure were used to evaluate the results.

RESULTS: Twenty-seven patients were followed with a median of 54 (range 15-108) months. In the three groups, the average AOFAS score improved from 75 (in all three groups) points preoperatively to 100 (group I), 97 (group II), and 90 points (group III) postoperatively. The rate of good-to-excellent result was 100% in group I and II and 73.3% in group III. Only in group III, recurrence occurred in five cases.

CONCLUSIONS: Diffuse PVNS of the ankle can be successfully managed with surgical synovectomy and adjuvant radiotherapy. Radiotherapy is not needed for localized PVNS. The recurrence rate in PVNS patients with extra-articular extension is higher.

LEVEL OF EVIDENCE: IV.