Description
Influence of Lateral Meniscus Posterior Root Tears on Static Anterior Tibial Subluxation of the Lateral Compartment after Anterior Cruciate Ligament Injury
Objective: The objective of this study was to determine the effect of lateral meniscus posterior root (LMPR) tears on static anterior tibial subluxation of the lateral compartment (ATSLC) in patients with anterior cruciate liga-ment (ACL) injuries, and to identify LMPR-related factors associated with ATSLC.
Methods: From January 2017 to December 2019, 421 patients under-going primary ACL reconstructions were retrospectively reviewed. Among them, 48 patients with combined ACL injuries and LMPR tears (ACL+LMPR group) and 53 patients with isolated ACL injuries (ACL group) were allo-cated respectively. Preoperative ATSLC were measured on magnetic resonance imaging and were further classified into large (≥6mm) and small (<6mm). The mean ATSLC and the pro-portion of patients with large ATSLC were compared between the two groups. In the ACL+LMPR group, pre-dictors of large ATSLC, including age, sex, body mass index, affected side, cause of injury, LMPR tear patterns, and meniscofemoral ligament (MFL) integrity were assessed by univariate analysis and multivariate logistic regression analysis.
Results: The mean ATSLC in the ACL+LMPR group was significantly greater than that in the ACL group (5.9 mm vs 3.0mm, P<0.001). The proportion of patients with large ATSLC in the ACL+LMPR group was also significantly higher than that in the ACL group (47.9% vs 15.1%, P<0.001). In addition, a root avulsion among LMPR tear patterns was determined to be an independent predictor of large ATSLC (OR 6.808, 95% CI 1.280-36.220, P=0.025), but age, sex, body mass index, affected side, cause of injury, and MFL integrity were not.
Conclusion: A concomitant LMPR tear was associated with excessive static ATSLC in ACL-injured patients. Among different LMPR tear patterns, the root avulsion further increased static ATSLC.
