At 6 weeks and 3 months postoperatively , the ROM in flexion group was 98.9510.33 and 110.054.93 respectively , with 87.628.92 and 95.626.51 in extension group , respectively ; The VAS score of anterior knee pain in flexion group was 2.021.38 and 2.210.87 , respectively , with 2.571.07 and 2.870.83 in extension group , respectively .