Clinical results of open synovectomy for treatment of diffuse pigmented villonodular synovitis of the knee: Case series and review of literature

Purpose: The purpose of current study was to evaluate recurrence of diffuse pigmented villonodular synovitis (DPVNS), functional outcome, and osteoarthritic change of the knee. Methods: Seventeen cases in 17 patients who had DPVNS of the knee that had not been previously treated were reviewed to determine the outcomes of surgical treatment. There were 10 males and 7 females, and their average age was 33.2 years (SD 17.2) at the time of first operation. Magnetic resonance imaging (MRI) was performed preoperatively to estimate the extent of the lesion. All patients were operated with open synovectomy. The mean postoperative follow-up period was 65.4 months (range 10.2 to 145.8; SD 48.3). Results: Two of 17 patients had posterior extra-articular lesions and recurrence. Two knees slightly reduced range of motion (from 145 to 130, from 145 to 125) and four knees progressed osteoarthritic changes, but overall postoperative results were satisfactory. Conclusions: Because DPVNS sometimes exists out of knee joint, we should adequately check the location of the lesions using preoperative MRI, and synovectomy should be performed throughout knee joint including extra-articular lesion, especially around ligaments, meniscus, and suprapatellar was completely resected. Level of Evidence: Therapeutic Level IV.