Double-bundle anterior cruciate ligament reconstruction: a computer-assisted orthopaedic surgery study

Abstract

Background: The biomechanical function of single-bundle anterior cruciate ligament reconstruction, in cadaveric studies, is successful in limiting anterior tibial translation in response to an anterior tibial load but seems to be insufficient to control a combined rotator load of internal and valgus torque. Anatomical double-bundle anterior cruciate ligament reconstruction might produce a better biomechanical outcome.

Hypothesis: The addition of the posterolateral bundle to the anteromedial bundle, in an in vivo double-bundle computer-assisted anterior cruciate ligament reconstruction, is able to reduce internal rotation of the tibia at 30 degrees of knee flexion, compared with a standard single-bundle reconstruction.

Study design: Controlled laboratory study.

Methods: Twenty consecutive anterior cruciate ligament reconstructions were performed in male patients in April and May 2006 with double-bundle gracilis and semitendinosus tendon grafts using the 2.0 OrthoPilot navigation system. Group A (10 patients) underwent standard single-bundle anterior cruciate ligament reconstruction with doubled gracilis and semitendinosus tendon graft; group B (10 patients) underwent double-bundle reconstruction with doubled gracilis and semitendinosus tendon graft. Anteroposterior displacement and internal and external rotation at 30 degrees of knee flexion were evaluated before and after reconstruction, using manual maximum force.

Results: Both techniques significantly reduced anteroposterior displacement and internal and external rotation of the tibia with respect to preoperative anterior cruciate ligament-deficient condition (P < .05). Comparing groups, no differences in anteroposterior tibial displacement and internal and external rotation of the tibia were found (anteroposterior, 3.7 mm and 5.2 mm; internal rotation, 16.3 degrees and 16.6 degrees; external rotation, 15.7 degrees and 15.1 degrees, respectively) in group A and B (P = .06, .90, and .72, respectively).

Conclusion: The hypothesis that addition of the posterolateral bundle to the anteromedial bundle is able to reduce internal rotation of the tibia at 30 degrees of knee flexion is not confirmed.

Clinical relevance: The effective role of the anatomical double-bundle procedure in better restoring knee kinematics should be questioned in an in vivo model.