Treatment of Pigmented Villonodular Synovitis of the Knee

Purpose: We aimed to determine the rate of local recurrence, the rate of postoperative complications, and the functional outcome at final follow-up of surgical and nonsurgical treatment approaches for pigmented villonodular synovitis (PVNS) of the knee. Methods: Medline, Embase, and the Cochrane Library were systematically searched for studies that reported the results of treatment for any type of PVNS between January 1, 1950, and August 1, 2013. Two authors extracted the data independently using predefined data fields including study quality indicators. Results: Sixty studies (1,019 patients) met the inclusion criteria. Thirty-five presented data on the treatment of localized pigmented villonodular synovitis (LPVNS), 40 on diffuse pigmented villonodular synovitis (DPVNS), 1 on extra-articular LPVNS, and 7 on DPVNS with extra-articular involvement. Many therapeutic options were reported. Depending on these options, DPVNS recurred in 8% to 70% of the series and LPVNS recurred in 0% to 8% of the series. For LPVNS, the 2 most-reported options were open localized synovectomy and arthroscopic local synovectomy. Between these 2 courses of treatment, no difference was found in terms of local recurrence (8.7% for open synovectomy and 6.9% for arthroscopic synovectomy) and postoperative complications (<1% for open synovectomy and 0% for arthroscopic synovectomy). For DPVNS, the 2 most-reported options were open total synovectomy and arthroscopic total synovectomy. Between these 2 courses of treatment, no difference was found in terms of local recurrence (22.6% for open synovectomy and 16.1% for arthroscopic synovectomy). However, we found a lower rate of reported complications between open synovectomy (19.3%) and arthroscopic synovectomy (0%). Internal irradiation or external beam radiation as an adjuvant treatment to surgical synovectomy seemed to decrease the rate of local recurrence in DPVNS cases with a high risk of recurrence. Finally, we found a great heterogeneity in the way the functional results were reported, and no valid conclusion could be made based on the data we extracted. Conclusions: We found no difference in local recurrence rates after open or arthroscopic surgery for either LPVNS or DPVNS. However, a lower rate of postoperative complications was reported after arthroscopic surgery for DPVNS.