Hip strength following hamstring tendon anterior cruciate ligament reconstruction.

OBJECTIVE

The objective of this study was to determine whether there is alteration in resultant joint moment of the hip extensors and adductors after hamstring anterior cruciate ligament (ACL) reconstruction.

DESIGN

Cross-sectional outcome analysis.

SETTING

University sport medicine center.

SUBJECTS: Fifteen subjects more than 1 year after ACL reconstruction with semitendinosus and gracilis tendons were compared with 15 matched controls with no knee injury.

INTERVENTIONS: Strength testing of the hip extensors and hip adductors of both limbs.

MAIN OUTCOME MEASUREMENTS: Isokinetic (50 degrees /s and 150 degrees /s) hip extensor strength test and isometric (15 degrees and 30 degrees ) hip adductor strength test.

RESULTS

Hip extensors increase in strength after hamstring ACL reconstruction, evening out normal side-to-side strength differences. Hip adductor strength deficits of up to 43% are demonstrated in the ACL reconstructed subjects compared with controls.

CONCLUSIONS

The identification of hip adductor strength deficits after hamstring harvest for ACL reconstruction may have important implications for both graft harvest site selection as well as postoperative rehabilitation protocols. Given the known existence of knee strength deficits after ACL reconstruction, increases in isovelocity hip extensor strength may contribute to increased lower limb strength imbalances. This may have implications for the ability of the lower limb muscles to protect the ACL graft.