Effect of isokinetic training of thigh muscle group on graft remodeling after anterior cruciate ligament reconstruction

Abstract

To investigate the effect of isokinetic training of thigh muscle group on graft remodeling after anterior cruciate ligament (ACL) reconstruction, and summarize the relevant rules to guide the clinic. Between August 2016 and December 2016, forty patients underwent arthroscopic ACL reconstruction using hamstring tendon were randomly divided into isokinetic group and control group ( n=20). The two groups of patients underwent staged rehabilitation treatment. The isokinetic group replaced the traditional intervention with the corresponding isokinetic strength training from 3 to 6 months after operation, and the traditional rehabilitation intervention was used in the control group. Finally, 12 cases of isokinetic group and 12 cases of control group with complete follow-up were enrolled in study. There was no significant difference in gender, age, body mass index, side of injury, the interval between injury and operation, and preoperative International Knee Documentation Committee (IKDC) score between the two groups ( P>0.05). The peak torque (PT) of knee extension and flexion and hamstring quadriceps ratio (H/Q) were measured at 3 months, 6 months, 12 months, and the second-look arthroscopy. The MRI examination was performed at the same time to evaluate graft remodeling. The shape, tension, and degree of vascularization of grafts were observed under arthroscopy. The grafts were harvested and observed by HE staining. The invertal between ACL reconstruction and the second-look arthroscopy was (23.57±3.23) months in isokinetic group and (23.22±3.56) months in control group, showing no significant difference between the two groups ( P>0.05). At the second-look arthroscopy, the IKDC score was 90.45±4.73 in isokinetic group and 89.32±4.54 in control group, showing significant differences when compared with preoperative scores in the two groups ( P<0.05). But there was no significant difference between the two groups ( t=0.868， P=0.404). At 3 months after operation, there was no significant difference in the PT of knee extension and flexion between the two groups ( P>0.05). At 6 months, 12 months, and the second-look arthroscopy, the PT of knee extension and flexion in isokinetic group were higher than those in control group ( P<0.05). The H/Q at 6 months and 12 months were higher in isokinetic group than in control group, and the differences were significant ( P<0.05). There was no significant difference in MRI score between the two groups at 3 months, 6 months, and the second-look arthroscopy ( P>0.05). The MRI score at 12 months was significantly higher in isokinetic group than in control group ( P<0.05). At the second-look arthroscopy, there was no significant difference in the arthroscopic score between the two groups ( P>0.05), and the histological score of the isokinetic group was superior to the control group ( P<0.05). On the basis of regular rehabilitation training, using the isokinetic training system to develop a suitable post-surgical isokinetic rehabilitation training program is helpful in early muscle strength recovery, early graft remodeling, and even long-term histological results after ACL reconstruction.