The Role of the Medial Meniscus in Anterior Knee Stability

Kousuke Shiwaku; Tomoaki Kamiya; Daisuke Suzuki; Satoshi Yamakawa; Hidenori Otsubo; Tomoyuki Suzuki; Katsunori Takahashi; Yohei Okada; Atsushi Teramoto; Hirofumi Ohnishi; Hiromichi Fujie; Toshihiko Yamashita

doi:10.1177/23259671221132845

The Role of the Medial Meniscus in Anterior Knee Stability

Orthop J Sports Med. 2022 Nov 11;10(11):23259671221132845. doi: 10.1177/23259671221132845. eCollection 2022 Nov.

Affiliations

¹ Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan.
² Department of Health Science, Hokkaido Chitose College of Rehabilitation, Chitose, Japan.
³ Department of Sports Medical Biomechanics, Graduate School of Medicine, Osaka University, Osaka, Japan.
⁴ Sapporo Sports Clinic, Sapporo, Japan.
⁵ Sapporo Maruyama Orthopaedic Hospital, Sapporo, Japan.
⁶ Department of Public Health, Sapporo Medical University School of Medicine, Sapporo, Japan.
⁷ Department of Mechanical Engineering, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo, Japan.

Abstract

Background: Few studies have compared the force distribution between the anterolateral, posterolateral, and medial structures of the knee.

Purpose: To investigate the important structures in an intact knee contributing to force distribution in response to anterior tibial load.

Study design: Controlled laboratory study.

Methods: Nine fresh-frozen cadaveric knee specimens underwent robotic testing. First, 100 N of anterior tibial load was applied to the intact knee at 0°, 15°, 30°, 60°, and 90° of knee flexion. The anterior cruciate ligament (ACL), anterolateral capsule, lateral collateral ligament, popliteal tendon, posterior root of the lateral meniscus, superficial medial collateral ligament, posterior root of the medial meniscus (MM), and posterior cruciate ligament were then completely transected in sequential order. After each transection, the authors reproduced the intact knee motion when a 100-N anterior tibial load was applied. By applying the principle of superposition, the resultant force of each structure was determined based on the 6 degrees of freedom force/torque data of each state.

Results: At every measured knee flexion angle, the resultant force of the ACL was the largest of the tested structures. At knee flexion angles of 60° and 90°, the resultant force of the MM was larger than that of all other structures with the exception of the ACL.

Conclusion: The MM was identified as playing an important role in response to anterior tibial load at 60° and 90° of flexion.

Clinical relevance: In clinical settings, the ACL of patients with a poorly functioning MM, such as tear of the MM posterior root, should be monitored considering the large resultant force in response to an anterior tibial load.

Keywords: anterior cruciate ligament; anterior tibial load; biomechanics; fresh-frozen cadaver; lateral meniscus; medial collateral ligament; medial meniscus; robotic system.