Rate of Torque Development in the Quadriceps after Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autografts in Young Female Athletes

This study aims to compare the limb symmetry index (LSI) of the rate of torque development (RTD) of the quadriceps with that of the peak torque after anterior cruciate ligament reconstruction (ACLR) using semitendinosus and gracilis tendon (STG) autografts and to investigate the associations of the LSI of torque parameters with patient-reported knee function. The participants included 23 female athletes after ACLR with STG grafts. Isometric quadriceps tests were performed using an isokinetic dynamometer. The peak torque, RTD(100) (0 to 100 ms) and RTD(200) (100 to 200 ms) were determined using torque-time curves. Comparisons of the LSI of torque parameters was performed by ANOVA. Univariate regression analysis was used to examine the relationship between the LSI of torque parameters and the patient-reported knee function. The LSIs of the peak torque and RTD(200) were significantly lower than that of the RTD(100) (p = 0.049, p = 0.039, respectively). Regression analysis showed that the LSI of the peak torque was associated with the patient-reported knee function (R(2) = 0.40, p = 0.001). It would be useful to evaluate the peak torque in young female athletes under the age of 18 and at 8–10 months after ACLR with STG grafts.