Semitendinosus repair augmentation of acute anterior cruciate ligament rupture.

The semitendinosus tendon has been used since 1980 by the senior author (J.P.M) to augment anterior cruciate ligament repair surgery in cases of acute rupture. There are two major criticisms of this technique: first, the semitendinosus tendon lacks adequate tensile strength functionally to replace the normal anterior cruciate ligament; and second, the semitendinosus is an important hamstring muscle, the loss of which has the potential to weaken the dynamic control of the knee. Objective measurement of success or failure of this procedure is provided by KT1000 arthrometer laxity testing for static recovery of stability, and by Cybex isokinetic dynamometer testing of peak torque and fatigue index to evaluate muscular rehabilitation. Thirty-seven patients were examined using these techniques in a standardized protocol at least two years after surgery. Results show excellent return of static stability and near-normal recovery of strength and endurance of quadriceps and hamstring muscles.