Relationship Between Anterior Cruciate Ligament Injury and Meniscus-Bone Angle

Area of Science:

• Orthopedics
• Biomechanics
• Sports Medicine

Background:

• The meniscus-bone angle (MBA) is an intrinsic factor linked to primary anterior cruciate ligament (ACL) injuries.
• Previous research has not isolated the influence of MBA and other intrinsic factors from extrinsic factors like sports activity level.

Purpose of the Study:

• To evaluate intrinsic factors associated with primary ACL injury, controlling for sports activity level.
• To test the hypothesis that MBA is a significant factor in ACL deficiency, regardless of sports activity.

Main Methods:

• A cross-sectional study involving 143 knees with ACL injuries and 143 matched control knees.
• Evaluation of patient height, weight, BMI, lateral and medial posterior tibial slope angles (LPTSA, MPTSA), MBA, and relative posterior inclination angle (RPIA).
• Logistic regression and receiver operating characteristic (ROC) curve analysis to determine significant factors and cutoff values.

Main Results:

• Lower MBA (22.3° vs 29.1°) and RPIA, and higher LPTSA (7.3° vs 5.0°) and MPTSA were observed in the ACL injury group (P < .001).
• MBA (OR, 0.645; P < .01) and LPTSA (OR, 1.3; P < .001) were significant independent predictors of ACL injury in logistic regression.
• An MBA cutoff value of 25.2° demonstrated 76.2% sensitivity and 83.9% specificity for predicting ACL injury (AUC, 0.88).

Conclusions:

• A low meniscus-bone angle (MBA), specifically below 25.2°, is the most significant independent predictor of primary ACL injury.
• This association remains significant even after controlling for differences in sports activity level.
• MBA is a crucial intrinsic anatomical factor contributing to ACL injury risk.