Pigmented villonodular synovitis in the ankle

Abstract

This is a case report of a 34 years old patient with left ankle periarticular pain for four years, attributed to sprain and other repeated episodes of sprain. The diffuse, long-lasting pain is effort-dependent and is accompanied by swelling and functional limitation. Initially the sprain was treated with cast immobilization and physiotherapy. When the acute trauma occurred, there was no evidence of other associated lesions and no additional tests were performed. As symptoms persisted, a MRI was order. MRI report (2004): “extensive median and medial chondral lesion of the left talus”. The patient did not accept the indication of surgery: mosaicplasty. He came to our office on February 2008 complaining about pain and functional limitation of increasing intensity and duration when compared to the initial symptoms four years ago, restricting his physical activities to exercises with backing. New MRI showed osteochondral lesion at the anteromedial of the talar domus and a similar lesion at the tibia. No synovial thickening was described. Surgery was indicated: periarticular debridement and mosaicplasty. During surgery with anteromedial approach, excessive synovial volume was observed with normal color and diffuse thickening; synovectomy was performed and the specimen was sent to anatomopatholgy. A big osteophyte at the anterior tibia and the dorsal talar neck was removed. Significant changes of the talus and tibia cartilages were treated with debridement leveling and multiple perforations. The pathologist’s diagnosis of the synovial specimen was pigmented villonodular synovitis. This diagnosis should always be remembered when an ankle strain presents atypical evolution.