2025 ISAKOS Biennial Congress ePoster
A Flat Reconstruction Of The Medial Collateral Ligament And Anteromedial Structures Restores Native Knee Kinematics - A Biomechanical Robotic Investigation
Adrian Deichsel, MD, Münster, NRW GERMANY
Christian Peez, MD, Münster, NRW GERMANY
Michael J. Raschke, MD, Prof., Münster GERMANY
Alina Albert, M.Sc., Münster, NRW GERMANY
Mirco Herbort, MD, Prof., Munich GERMANY
Christoph Kittl, MD, MD(res), Muenster GERMANY
Christian Fink, MD, Prof., Innsbruck AUSTRIA
Elmar Herbst, MD, PhD, Muenster GERMANY
Department of Trauma, Hand and Reconstructive Surgery, University Hospital Münster, Münster, NRW, GERMANY
FDA Status Not Applicable
Summary
Insufficiency of the superficial and deep MCL leads to excess laxity in valgus, external tibial rotation, anterior tibial translation, and anteromedial translation, which can be restored by a combined flat reconstruction of the superficial MCL and the anteromedial corner.
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Abstract
Background
Instabilities of the superficial medial collateral ligament (sMCL) and anteromedial structures of the knee result in excess valgus and external tibial rotation as well as tibial translation. Different techniques exist for reconstruction of the anteromedial structures, of which many are not biomechanically validated.
Purpose
To evaluate a flat reconstruction of the sMCL and anteromedial structures in restoring knee kinematics in the combined MCL and anteromedial deficient knee.
Methods
Eight cadaveric knee specimens were tested in a 6 degrees of freedom robotic test setup. Force-controlled clinical laxity tests were performed with 200 N of axial compression in 0°, 30°, 60°, and 90° of flexion: 8 Nm valgus torque, 5 Nm external tibial rotation (ER) torque, 89 N anterior tibial translation (ATT) force, and an anteromedial drawer test consisting of 89 N ATT force under 5 Nm ER torque. After determining the native knee kinematics, the sMCL was transected, followed by the deep MCL. Subsequently, a flat reconstruction of the sMCL and anteromedial structures, utilizing a rectangular femoral bone tunnel, was performed. Mixed linear models were used for statistical analysis (P < 0.05).
Results
Cutting of the sMCL led to statistically significant increased laxity regarding valgus rotation, external tibial rotation, anterior tibial translation, and anteromedial translation in all tested flexion angles (P < 0.05). A combined instability of the sMCL and dMCL led to further increased knee laxity in all tested kinematics and flexion angles (P < 0.05). After flat reconstruction of the deficient structures, the knee kinematics were not significantly different from the native state (P = n.s.).
Conclusion
Insufficiency of the superficial and deep MCL leads to excess laxity in valgus, external tibial rotation, anterior tibial translation, and anteromedial translation, which can be restored by a combined flat reconstruction of the superficial MCL and the anteromedial corner.