Effect of Injury to the Lateral Meniscotibial Ligament and Meniscofibular Ligament on Meniscal Extrusion: Biomechanical Evaluation of the Capsulodesis and Centralization Techniques in a Porcine Knee Model

Abstract

Background: Previous biomechanical studies of the meniscotibial ligament have determined that it contributes to meniscal stability. An injury to it can cause the meniscus to extrude, and reconstruction of that ligament significantly reduces extrusion. Purpose: To assess the biomechanical effects of sectioning the lateral meniscotibial ligament (LMTL) and the meniscofibular ligament (MFL) with respect to the radial mobility of the lateral meniscus and to evaluate the biomechanical effects of the capsulodesis and centralization techniques. Study Design: Controlled laboratory study. Methods: The lateral meniscus of 22 porcine knees was evaluated. They were mounted on a testing apparatus to apply muscle and ground-reaction forces. The meniscus was evaluated at 30° and 60° of knee flexion using 2 markers placed on the posterior cruciate ligament and the lateral meniscus after applying an axial compression of 200 N to the knee joint. Measurements were recorded under 5 conditions: intact lateral meniscus, injury of the LMTL, subsequent injury of the MFL, the use of the open capsulodesis technique, and the reconstruction of the LMTL and the MFL with the centralization technique. Results: The distance between the 2 markers was significantly greater in the extrusion group (combined lesion of the LMTL and MFL) than in the intact or reconstruction groups (capsulodesis and centralization techniques; P < .001 in all cases). In the cases of load application, no significant differences were observed between the control group (intact meniscus) and the groups on which the reconstruction techniques were performed. There were also no differences when comparing the results obtained between both reconstruction techniques. In all settings, the distance between the 2 markers increased with the increase in the knee flexion angle. Conclusion: In a porcine model, the LMTL and the MFL participated as restrictors of the radial mobility of the lateral meniscus during loading. Their injury caused a significant increase in lateral meniscal extrusion, and the centralization and the capsulodesis procedures were able to reduce extrusion. Clinical Relevance: This study demonstrates the capacity of the LMTL and the MFL to restrict the radial mobility of the lateral meniscus during loading and how it is affected when they are injured.

Meniscal extrusion consensus statement: A collaborative survey within the Meniscus International Network (MenIN) Study Group

“…Specifically, weight loss and a low BMI have previously been reported to positively affect meniscal extrusion and meniscal healing following posterior medial meniscus root repair, highlighting the importance of BMI for both classification and prognosis [13]. Considering the implications of a meniscal extrusion classification system, respondents in the current study advocated for a classification addressing OA progression, treatment approaches, a grading system, clinical outcomes/prognosis, stability or progression of meniscal extrusion, dynamic factors, centralization procedures and reducibility [23]. Various classification systems have been proposed to categorize meniscal extrusion, and these existing systems aim to provide clinicians with standardized frameworks for assessing the severity, stability and prognostic implications of meniscal extrusion [1, 3].…”