Results of total knee arthroplasty in patients with gonarthrosis resulting from the delayed diagnosis of PVNS: a case series

Pigmented villonodular synovitis (PVNS) is a benign tumor that affects synovial lined joints, tendon sheaths and bursae. It is most commonly seen in one knee joint. The recommended treatment is total synovectomy, while radiotherapy can be used as adjuvant therapy for patients at risk for recurrence. The aim of our study was to show that the devastating effects of inactive diffuse PVNS may not be recognized for years and to evaluate the efficiency of aggressive total synovectomy on patients with PVNS during a follow-up period of 5 years. In the present study, 5 knees of four patients who had been previously followed due to gonarthrosis and diagnosed with PVNS during total knee arthroplasty (TKA) were followed and evaluated for a mean duration of 68 months. Mean age of the patients was 61.2 (52–66). All patients were women. One patient had right knee involvement, two had left knee involvement, and one had both knees involved. All patients had diffuse PVNS. Total synovectomy was performed in all patients in addition to TKA. During the follow-up, recurrence was not seen in any of the patients and prosthesis loosening was not detected. The aim of the present study was to evaluate the effectiveness of total synovectomy over the 5 years following the operation and to show that the devastating effects of inactive PVNS may sometimes be overlooked for years before being recognized during the treatment of the gonarthrosis that develops due to the disease. Although the disease is generally monoarticular, the study also presents a patient with bilateral PVNS.