Double-Bundle Medial Collateral Ligament Reconstruction Improves Anteromedial Rotatory Instability.

BACKGROUND

New techniques have been proposed to better address anteromedial rotatory instability in a medial collateral ligament (MCL)-injured knee that require an extra graft and more surgical implants, which might not be feasible in every clinical setting.

PURPOSE

To investigate if improved resistance to anteromedial rotatory instability can be achieved by using a single-graft, double-bundle (DB) MCL reconstruction with a proximal fixation more anteriorly on the tibia, in comparison with the gold standard single-bundle (SB) MCL reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic simulator in intact knee, superficial MCL/deep MCL-deficient, and reconstruction states. Three different reconstructions were tested: DB MCL no proximal tibial fixation and DB and SB MCL reconstruction with proximal tibial fixation. Knee kinematics were recorded at 0°, 30°, 60°, and 90° of knee flexion for the following measurements: 8 N·m of valgus rotation (VR), 5 N·m of external tibial rotation, 5 N·m of internal tibial rotation, combined 89 N of anterior tibial translation and 5 N·m of external rotation for anteromedial rotation (AMR) and anteromedial translation (AMT). The differences between each state for every measurement were analyzed with VR and AMR/AMT as primary outcomes.

RESULTS

Cutting the superficial MCL/deep MCL increased VR and AMR/AMT in all knee positions except at 90° for VR (

CONCLUSION

In this in vitro cadaveric study, a DB MCL reconstruction with anteriorly placed proximal tibial fixation was able to control AMR and AMT better than the gold standard SB MCL reconstruction.

CLINICAL RELEVANCE

In patients with anteromedial rotatory instability and valgus instability, a DB MCL reconstruction may be superior to the SB MCL reconstruction, without causing extra surgical morbidity or additional costs.

Déclaration de conflit d'intérêts

One or more of the authors has declared the following potential conflict of interest or source of funding: Support was received from Smith & Nephew Inc in the form of a research grant that funded the presented research; Ossur Inc in the form of an educational grant for the authors’ research fellowship position; the Natural Sciences and Engineering Research Council (NSERC) Discovery: RGPIN-2018-05693; the Ontario Early Researcher Award ER18-14-197; and the Canadian Foundation for Innovation JELF and Ontario Research Fund—Research Infrastructure: 38141. A.G. has received consulting fees from Smith & Nephew; is on the advisory board of and holds stock in Spring Loaded Technologies; and holds stock in OS LinkX Robotics and Ostesys Robotics. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.