Fig. (3) The measurement of ROI in femoral condyle and proximal tibia. In the tibial condyles, 3 square regions of interest were marked with a square on the proximal tibia. The medial tibial condyle BMDs in medial sqaure region of interest and the lateral tibial condyle BMDs in lateral square region of interest were calculated for the tibia. And we calculated the BMD of both lateral and medial femoral condyle in sqaure region of interest of the same size as those on the tibial condyles.