results of total knee arthroplasty in patients with pigmented villonodular synovitis-reporting three cases

Introduction: the knee is the most commonly affected joint in the pigmented villonodular synovitis (pvns). if misdiagnosed or mismanaged, pvns, especially the diffused form can destroy joints and can result in terminal degenerative joint disease. case presentation: we report 3 cases of diffuse form of pvns with grade 3 osteoarhtritis that is treated by total synovectomy and total knee arthroplasty (tka). the mean duration of the follow-up was 46.5 (9, 11, 120) months. in 2 cases, staged posterior then anterior synovectomy and tka were done with excellent results. in 1 case, simultaneous synovectomy and tka was performed with hematoma formation postoperatively and quadriceps tendon rupture 10 weeks later with fair final result. conclusions: tka in pvns is a challenging procedure.we recommend open posterior synovectomy then anterior synovectomy and tka in 2 separate operations. quadriceps mechanism must be protected during synovectomy.