Replacement of the lateral condyle subchondral bone medulla by a dense tissue mass of 230 H.U. (mean density, SD +/- 131 H.U., [-131; 1055]), slightly calcified, although without the ring and arc pattern of a cartilaginous matrix. Intraarticular deposits of the same density were also seen adjacent to the cruciate ligaments. The cartilage was relatively well-preserved in the lateral compartment of the left knee.