Combined arthroscopic and open synovectomy for diffuse pigmented villonodular synovitis of the knee

Purpose There are few reports detailing recurrence rates or functional outcomes after combined arthroscopic and open synovectomy to treat diffuse pigmented villonodular synovitis (DPVNS) of the knee. Methods Patients with DPVNS of the knee treated with combined synovectomy, followed for a minimum of 12 months at a tertiary orthopaedic oncology centre, were identified. We extracted data pertaining to demographics, complications, clinical outcomes and recurrence. Functional status was evaluated prospectively using the Toronto Extremity Salvage Score (TESS) and the Musculoskeletal Tumor Society (MSTS) 1987 and 1993 surveys. Data were reported descriptively as mean (SD) unless otherwise specified. Results Fifteen patients [80 % female; mean age 38.9 (SD 14.2) years] representing 15 knees were treated with combined synovectomies and followed for 81 (SD 55) months. Posterior arthroscopy was utilized in 73 % of patients. External beam radiation was utilized post-operatively in 73 % of patients. Two patients (13 %) experienced symptomatic disease recurrence. The mean post-operative knee range of motion was 1° (range 0–10°) to 115° (range 90–135°). TESS and MSTS 1987/1993 scores all suggested excellent patient function. Post-operative complications included one posterior wound dehiscence, one case of femoral condyle avascular necrosis and one patient with lymphedema. Conclusions Combined synovectomy resulted in a low rate of symptomatic disease recurrence and good to excellent functional outcomes for diffuse PVNS of the knee. A literature review identified this as largest case series focusing on combined synovectomies for DPVNS of the knee and the only one describing functional outcomes or the use of external beam radiotherapy. Level of evidence Retrospective case series, Level IV.