Fig. 2.

Three-dimensional reconstruction of distal femur and Histomorphometric comparison by micro-computed tomography scans at 4, 8, and 12 weeks between CON and EXP groups. We regard the trochlear depth and sulcus angle of the control group at different time points as normal values. Over time, the trochlear groove became significantly flatter and sulcus angle became significantly larger, compared with the control group at 8, 12 weeks after surgery. In the experimental group, micro-CT displayed obvious loss of subchondral bone at 8 weeks after surgery, and became more and more serious with time. *P < 0.05 (BV/TV: bone volume to total volume; TB.N: trabecular number; TB.Th: trabecular thickness; TB.Sp: trabecular separation; BMD: bone mineral density; CON, control; EXP, experimental).