A 24 year old man presented with complaints of multiple episodes of pain and swelling in the right knee joint from childhood. There is a history of prolonged bleeding following trivial trauma.
There is a large, dense soft tissue swelling surrounding the joint.There is symmetrical loss of joint space with subchondral cysts and periarticular erosions. There is bulbous enlargement of the femoral condyles with flattened condylar surfaces. The intercondylar notch is wide and deep. The inferior margin of the patella is flattened.