Single-bundle MCL reconstruction with anatomic single-bundle ACL reconstruction does not restore knee kinematics.

ABSTRACT

PURPOSE: The purpose of this study was to evaluate and compare knee kinematics and kinetics following either single bundle, modified triangular or double-bundle reconstruction of the superficial medial collateral ligament (sMCL) with single bundle anatomic ACL reconstruction. METHODS: Using a cadaveric model (n = 10), the knee kinematics and kinetics following three MCL reconstructions (single-bundle (SB), double-bundle (DB), modified triangular) with single bundle anatomic ACL reconstruction were compared with the intact and deficient knee state. The knees were tested under (1) an 89-N anterior tibial load, (2) 5 N-m internal and external rotational tibial torques, and (3) a 7 N-m valgus torque. RESULTS: Anatomic ACL reconstruction with SB MCL reconstruction was able to restore anterior tibial translation and external rotation to intact knee values but failed to the internal and valgus rotatory stability. Anatomical DB MCL reconstruction (with SB ACL reconstruction) and the modified triangular MCL reconstruction (with SB ACL reconstruction) restored all knee kinematics to the intact value. CONCLUSION: This study shows that clinical presentation with combined ACL and severe sMCL injury, single-bundle MCL with single-bundle ACL reconstruction does not restore knee kinematics. Anatomical double-bundle MCL reconstruction may produce slightly better biomechanical stability than the modified triangular MCL reconstruction, but the modified triangular reconstruction might be more clinically practical with the advantages of being less invasive and technically simpler while at the same time can restore a nearly normal knee joint.