Summary
Posteromedial viewing at the time of ACLR surgery increases the reliability of detection and specificity of medial meniscal tear types, over anterior viewing alone and the incidence and complexity of MM tear types increased significantly with increasing time intervals between the injury and the ACLR. Other factors associated with increased findings of MMLs were male gender, high BMI and LM tears.
Abstract
Background
Medial meniscus lesions (MMLs) are a common finding at the time of anterior cruciate ligament reconstruction (ACLR) surgery. Evaluation of the posteromedial compartment reduces the risk of missed diagnoses of MMLs.
Purpose
The primary objective of this study was to determine the incidence and types of MMLs in patients undergoing ACLR, when using a standardized arthroscopic approach that included posteromedial compartment evaluation. With an end towards understanding how the incidence and types of MMLs changed with increasing time intervals between injury and surgery, our secondary objective was to investigate if any causal relationship existed between the delay, the types of MMLs, and what factors were associated with MMLs.
Methods
A retrospective analysis was performed on patients who underwent primary ACLR’s between January 2013 and March 2023. The epidemiology was defined by categorizing the time interval incidence and spectrum of medial meniscal (MM) tear types from the time of injury to surgery. Concomitant factors were analyzed using a logistic regression model.
Results
Overall, MMLs were identified in 1851 (39.4%) of 4697 patients undergoing ACLR. The incidence of MMLs was 33.1% for the 0-3, 38.7% for the 3-12 and 59.6% for the >12 months time interval period, and significant for the >3 months (OR 1.320; 95% CI, 1.155-1.509; p <.0001) and >12 months (OR 3.052; 95% CI, 2.553-3.649; p <.0001) periods. There were increased ramp lesions and significant increases in the incidence of the more complex MM, bucket handle, and/ or flap tear patterns (p<.0001). A significant increase in MMLs was also observed in patients of male sex (OR 1.501; 95% CI, 1.304-1.729; p <.0001), those with a BMI =25 (OR 1.193; 95% CI, 1.046-1.362; p =.0088) and in those with concomitant lateral meniscus (LM) lesions (OR 1.737; 95% CI, 1.519-1.986; p <.0001).
Conclusion
Overall, MMLs were identified in 39.4% of 4697 patients undergoing ACL reconstruction when posteromedial compartment evaluation was performed. The incidence of MMLs and the complexity of MM tear types increased significantly with increasing time intervals between the index injury and the ACLR. Secondary factors that were associated with increased findings of the presence of MMLs included male gender, increased BMI and LM lesions.
What is already known on this topic: MMLs have a variably reported incidence in ACL-deficient knees. It is increasingly recognized that posteromedial compartment evaluation is essential to avoiding a missed diagnosis of medial meniscus pathology, and that previous studies have likely underestimated the rate, spectrum and severity of MMLs noted with delays between injury and ACLR surgeries. What this study adds: To the authors’ knowledge, this is the first study to report the incidence of MMLs in a large series of patients undergoing ACLR with a visualization of the posteromedial compartment of the knee. It provides a large consensus for a more comprehensive and reliable analysis of the incidence and severity of MMLs with ACL tears.