Internal and external tibial rotation strength after anterior cruciate ligament reconstruction using ipsilateral semitendinosus and gracilis tendon autografts

The internal and external tibial rotation torques of subjects who had under gone anterior cruciate ligament reconstruction using semitendinosus and gra cilis tendon grafts were measured to determine whether harvest of the tendo ns results in weakness of tibial internal and external rotation. Cybex NORM dynamometer examinations were performed to measure internal and external t ibial torque at angular velocities of 60, 120, and 180 deg/sec in 23 subjec ts. The sex-specific average torque data of the reconstructed limbs were co mpared with those of the contralateral limbs. Relative internal and externa l torque scores were calculated for each subject by subtracting the peak to rque of the reconstructed knee from that of the contralateral knee. These r elative scores were averaged and compared with the null hypothesis that eac h score should be statistically similar to zero. Subjects were evaluated at an average of 51 +/- 40 months postoperatively. The mean relative internal torque scores of the reconstructed limbs showed a statistically significan t decrease from those of the contralateral limbs at all angular velocities. The mean relative external torque scores of the reconstructed limbs were s tatistically similar to those of the contralateral limbs at all angular vel ocities. Subjects who had undergone ligament reconstruction using semitendi nosus and gracilis tendons demonstrated internal tibial rotation weakness i n their reconstructed knees compared with their contralateral knees at all angular velocities tested. These results suggest that semitendinosus and gr acilis tendon harvest causes weakness of internal tibial rotation.