To evaluate in-vivo the effectiveness of the double bundle technique for Anterior Cruciate ligament (ACL) reconstruction in restoring knee rotational stability under varying dynamic loading conditions.

The study group included 10 patients who underwent double-bundle ACL reconstruction with hamstrings tendon autograft, 12 patients with single-bundle reconstruction, 10 ACL deficient subjects and 12 healthy control individuals. Kinematic and kinetic data were collected using an 8-camera optoelectronic motion analysis system and one force plate. Knee rotational stability was examined during two maneuvers: a combined 60o pivoting turn and immediate stairs ascend and a combined stairs descend and immediate 60o pivoting maneuver. The two factors evaluated were the maximum

There were no significant differences in tibial rotation between the four groups in the examined maneuvers. Tibial rotation in the single- and the double-bundle groups were even lower than the control group. Rotational moments did not differ significantly between the four groups in any of the examined maneuvers. In general, rotational moments in the affected side of the ACL reconstructed and deficient groups were found reduced compared to the unaffected side.

Double-bundle reconstruction does not reduce knee rotation further compared to the single-bundle technique during dynamic stability testing under varying conditions. The injured side of ACL reconstructed or deficient individuals is exposed to substantially lower rotational moment compared to the intact side.