Concomitant lateral meniscal tear is the most important factor associated with lateral meniscal extrusion after anterior cruciate ligament reconstruction surgery.

Abstract

This study aimed to evaluate whether intraoperative injury to the lateral meniscus anterior root (LMAR) is associated with postoperative lateral meniscal extrusion (LME) during primary anterior cruciate ligament reconstruction (ACLR) surgery. Other potentially postoperative LME causal factors were also evaluated such as concomitant lateral meniscal (LM) tear and the surgical method used (single- vs. double-bundle technique). retrospective study of all consecutive primary ACLRs performed between 2015 and 2021 at a single hospital was conducted in patients without a prior history of knee lesions. Surgical methods were categorized as single- or double-bundle techniques. Preoperative and 12-month postoperative magnetic resonance imaging were used to assess LMAR injury (absolute attachment-width and baseline-referenced injury rate) and absolute LME on the corresponding coronal slice. The association between LMAR injury and LME was evaluated. Factors associated with LME, including the surgical technique and the presence of a concomitant LM tear, were evaluated using multiple linear regression. A total of 102 patients met the inclusion criteria. LMAR injury did not significantly correlate with LME. The single-bundle ACLR was associated with a significantly higher LMAR injury rate than the double-bundle technique (27.3% vs. 5.7%, P < 0.001) and lateral deviation of the bone tunnel position correlated positively with the LMAR injury rate; however, neither factor resulted in greater LME. In multiple linear regression, the single-bundle technique (β = 0.70, P < 0.001) and concomitant LM tear (β = 0.99, P < 0.001) were independently associated with greater postoperative LME. The LMAR injury alone may not contribute significantly to LME postoperatively. Lateral tibial tunnel creation during ACLR correlated with increased LMAR injury; however, it did not directly increase LME. Concomitant LM tears were a statistically significant predictor of postoperative LME. Although these findings are based on short-term imaging assessments rather than on structural osteoarthritis outcomes, they may help refine surgical strategies to minimize the risk of LME. Level Ⅲ, Retrospective comparative study.