What factors associate with medial meniscal extrusion after anterior cruciate ligament reconstruction: An analytical observational study

Abstract

Abstract Background Medial meniscal extrusion (MME) is a valuable clinical sign for early detection of osteoarthritis (OA). Thus, post-anterior cruciate ligament reconstruction (ACLR) MME is a potential predictor of postoperative OA. We aimed to examine MME variations before and after ACLR including the influence of suture medial meniscus (MM) injuries. Methods We analysed 92 knees from 92 patients who underwent anatomic ACLR. Multiple linear regression analysis was conducted using 1-year post-operative MME as the dependent variable, and age, sex, body mass index, preoperative MME, and MM treatment as independent variables. MM treatment was categorised into three groups: no MM injury and no suture [N/N], MM injury but no suture [I/N], and MM injury and suture [I/S]. A paired t-test was performed on the three groups and all patients to compare the pre- and 1-year post-operative MME. Results The factors significantly affecting post-operative MME were preoperative MME (P = 0.004) and I/S (P < 0.001). Additionally, the paired t-test showed no significant differences between the pre- and post-operative MME in all groups. Pre- and post-operative MME in the N/N group were 1.89 ± 0.85 and 1.71 ± 0.49 mm (P = 0.17), respectively; in the I/N group, 1.87 ± 0.91 and 1.84 ± 0.73 mm (P = 0.91) respectively; and in the I/S group, 2.40 ± 1.14 and 2.80 ± 0.77 mm (P = 0.12), respectively. Conclusions Preoperative MME and I/S were significantly associated with greater MME after ACLR. The evaluation of post-ACLR outcomes using MME should consider preoperative MME and MM injuries that require suture.