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The superficial medial collateral ligament is the major restraint to anteromedial instability of the knee.

Authors :
Wierer G
Milinkovic D
Robinson JR
Raschke MJ
Weiler A
Fink C
Herbort M
Kittl C
Source :
Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA [Knee Surg Sports Traumatol Arthrosc] 2021 Feb; Vol. 29 (2), pp. 405-416. Date of Electronic Publication: 2020 Apr 10.
Publication Year :
2021

Abstract

Purpose: The purpose of the present study was to determine how the medial structures and ACL contribute to restraining anteromedial instability of the knee.<br />Methods: Twenty-eight paired, fresh-frozen human cadaveric knees were tested in a six-degree of freedom robotic setup. After sequentially cutting the dMCL, sMCL, POL and ACL in four different cutting orders, the following simulated clinical laxity tests were applied at 0°, 30°, 60° and 90° of knee flexion: 4 Nm external tibial rotation (ER), 4 Nm internal tibial rotation (IR), 8 Nm valgus rotation (VR) and anteromedial rotation (AMR)-combined 89 N anterior tibial translation and 4 Nm ER. Knee kinematics were recorded in the intact state and after each cut using an optical tracking system. Differences in medial compartment translation (AMT) and tibial rotation (AMR, ER, IR, VR) from the intact state were then analyzed.<br />Results: The sMCL was the most important restraint to AMR, ER and VR at all flexion angles. Release of the proximal tibial attachment of the sMCL caused no significant increase in laxity if the distal sMCL attachment remained intact. The dMCL was a minor restraint to AMT and ER. The POL controlled IR and was a minor restraint to AMT and ER near extension. The ACL contributed with the sMCL in restraining AMT and was a secondary restraint to ER and VR in the MCL deficient knee.<br />Conclusion: The sMCL appears to be the most important restraint to anteromedial instability; the dMCL and POL play more minor roles. Based on the present data a new classification of anteromedial instability is proposed, which may support clinical examination and treatment decision. In higher grades of anteromedial instability an injury to the sMCL should be suspected and addressed if treated surgically.

Details

Language :
English
ISSN :
1433-7347
Volume :
29
Issue :
2
Database :
MEDLINE
Journal :
Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA
Publication Type :
Academic Journal
Accession number :
32277264
Full Text :
https://doi.org/10.1007/s00167-020-05947-0