RESUMO
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.
RESUMO
BACKGROUND: Lateral extra-articular tenodesis (LET) is one of the most widely used procedures to restore anterolateral stability. Clinical outcomes after the addition of LET to anterior cruciate ligament (ACL) reconstruction (ACLR) have been widely investigated; however, the potential influence of LET on the ACL ligamentization process has not been examined. PURPOSE/HYPOTHESIS: The purpose was to use 10-month postoperative magnetic resonance imaging (MRI) scans to determine whether the maturity of grafts after hamstring autograft ACLR was affected by concomitant LET. The hypothesis was that when modified Lemaire lateral extra-articular tenodesis (MLLET) was performed, the MRI parameters of ACL graft maturity would be modified. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The study included patients treated between December 2017 and December 2018 who had undergone anatomic 3-strand hamstring tendon autograft ACLR, with or without concomitant MLLET, and had undergone MRI 10 months postoperatively. Thus, the study included 30 patients who had isolated ACLR and 22 patients who had ACLR plus MLLET. The 2 groups were comparable based on all criteria analyzed. To evaluate graft maturity, the signal-to-noise quotient (SNQ) was measured in 3 regions of interest of the proximal, midsubstance, and distal ACL graft. Lower SNQ ratios indicate less water content and, theoretically, better maturity and healing of the graft. RESULTS: The mean ± SD for SNQ was 4.62 ± 4.29 (range, 3.12-6.19) in the isolated ACLR group and 7.59 ± 4.68 (range, 4.38-8.04) in the ACLR plus MLLET group (P = .012). Upon comparing the mean values of the 3 portions between the 2 groups, we found a significant difference between the 2 groups for the proximal and middle portions (P = .007 and P = .049, respectively) but no difference in the distal portion (P = .369). CONCLUSION: At the 10-month follow-up, hamstring tendon autografts for anatomic ACLR with MLLET did not show the same MRI signal intensity compared with isolated hamstring anatomic ACLR.