2023 ISAKOS Biennial Congress ePoster
Deep Medial Collateral Ligament Reconstruction of the Knee Restores Rotational Stability Throughout Full Range of Motion While Contemporary MCL Reconstruction Only Does in Extension
Kyle Borque, MD, Houston, TX UNITED STATES
Shuyang Han, PhD, Bellaire, Texas UNITED STATES
John Gold, BS, Houston, TX UNITED STATES
Ethan Sij, BS, Houston, Texas UNITED STATES
Andrew A. Amis, FREng, DSc, PhD, London UNITED KINGDOM
Andy Williams, MBBS, FRCS(Orth), FFSEM(UK), London UNITED KINGDOM
Walter Richard Lowe, MD, Houston, TX UNITED STATES
Mitzi S Laughlin, PhD, Sugar Land, Texas UNITED STATES
Philip C. Noble, PhD, Houston, TX UNITED STATES
Houston Methodist, Houston, Texas, UNITED STATES
FDA Status Not Applicable
Summary
Deep MCL reconstruction restored rotational stability to the knee throughout range of motion but did not restore valgus stability. The contemporary MCL reconstruction restore stability only near full extension.
ePosters will be available shortly before Congress
Abstract
Introduction
Injuries to the medial ligament complex result in valgus and anteromedial rotatory instability (AMRI). Historic MCL reconstruction techniques have focused on the superficial MCL in an effort to restore valgus stability while frequently ignoring the importance of the deep MCL in controlling tibial external rotation.
Objective
To assess and compare the ability of a contemporary medial collateral ligament (MCL) reconstruction and a deep MCL (dMCL) reconstruction to restore rotational and valgus stability to the knee.
Methods
Six pairs fresh-frozen cadaveric knee specimens were included and with intact soft tissue, the distal femur and tibia were potted in PVC pipes to facilitate biomechanical testing using a customized multi-axial knee activity simulator. Four states were tested: 1) intact 2) after sectioning of the sMCL and dMCL, 3) contemporary MCL reconstruction as described by LaPrade et al, and 4) dMCL reconstruction. In each state, the knees were tested under four loading conditions at varying flexion angles (0°, 20°, 40°, 60° and 90°): 8 Nm valgus torque, 5 Nm tibial external rotation torque, 90N anterior drawer, and combined 90 N anterior drawer plus 5 Nm tibial external rotation torque.
Results
Transection of the sMCL and dMCL resulted in increased laxity with the application of the valgus torque, external rotation torque, and combined anterior drawer plus external rotation at all flexion angles. dMCL reconstruction restored external rotation stability to intact levels (all p<0.05) throughout all degrees of flexion, yet dMCL reconstruction did not restore valgus stability at any flexion angle. Contemporary MCL reconstruction restored valgus and external rotation stability at 0° and 20° and valgus stability at 40° (p<0.01). In response to a combined anterior drawer plus tibial external rotation, the dMCL restored stability back to the intact level at 20° and improved stability between 40° and 90° flexion. In contrast, the contemporary MCL reconstruction did not restore stability at any degree of flexion (p>0.05).
Conclusion
Deep MCL reconstruction restored rotational stability to the knee throughout range of motion but did not restore valgus stability. The contemporary MCL reconstruction restore stability only near full extension.