Three-dimensional kinematic and kinetic analysis of knee rotational stability after single- and double-bundle anterior cruciate ligament reconstruction.

PURPOSE: To investigate whether anatomic restoration of the anterior cruciate ligament (ACL) functional bundles results in significant reduction in transverse-plane instability compared with the conventional single-bundle technique during a dynamic 60 degrees pivoting maneuver with the supporting knee in extension.
METHODS: Using an 8-camera optoelectronic system and a force plate, we examined 10 patients with double-bundle ACL reconstruction, 12 patients with single-bundle reconstruction, 10 ACL-deficient subjects, and 10 healthy control individuals. The 4 groups did not differ in terms of age, body mass index, duration of follow-up, and number of meniscectomies performed. Kinematic and kinetic data were collected from these subjects while performing a pivoting maneuver on each side with the supporting knee in extension. Maximum range of motion for internal-external knee rotation and maximum knee rotational moment were examined.
RESULTS: There was no significant difference in tibial rotation either between the 4 groups or between sides. The mean knee rotation for the single- and double-bundle groups was lower than the control group. Rotational moment values were substantially reduced on the affected side of the reconstructed and the ACL-deficient groups. However, rotational moment was not found to affect the degree of angular displacement significantly.
CONCLUSIONS: Double-bundle ACL reconstruction does not reduce knee rotation further compared with the single-bundle reconstruction technique. The affected side of ACL-deficient or -reconstructed individuals is subjected to reduced knee rotational moments compared with the intact side during stressful functional maneuvers. LEVEL OF EVIDENCE: Level III, retrospective comparative study. Copyright (c) 2010 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.