THY1 and osteochondritis dissecans: Higher proportions of cells showing positive expression for CD90 were found in SF-H (64.9 %) and SM-H (66.6 %) (P <0.05), suggesting that cells from healthy SF or SM are better sources of MSCs than are cells from SF-OCD (48.3 %), SF-OA (48.1 %), SM-OCD (40.2 %), or SM-OA (40.3 %).