Pigmented villonodular synovitis of the knee

Abstract

Pigmented villonodular synovitis is a disorder involving synovial proliferation of the joints, bursa or tendon sheats. It occurs in two form: a diffuse disease involving the entire synovium or a discrete nodular mass involving only a small section of the synovium. The knee joint is most commonly affected. Misdiagnosis of meniscal lesions and other knee disorders are frequent. Five hundred and seventy six knee arthroscopies were performed between January 1992 and January 1997. Ten (1.7%) cases of diffuse pigmented villonodular synovitis were diagnosed arthroscopically. Clinical presentation, consisted of insidious onset of joint swelling with discomfort, pain, joint stiffness, instability, thigh artrophy, and local temperature elevation. All ten patients had an arthroscopy and biopsy of the knee for diagnostic purposes. Six patients had artroscopic total synovectomy and the remaining 3 patients had open synovectomy. One patient with osteoarthritic changes went on synovectomy and total knee prosthesis during the same session. Mean follow-up period was 27 months (range 6-66 mo.). Of the two patients who had recurrences, one had subsequent open synovectomy, other patient had developed progressive destruction and subchondral cystic invasion and knee arthrodesis was eventually done