Is Trochlear Dysplasia Associated with a High Prevalence of Repaired Anterior Medial Portal Lesions in Anterior Cruciate Ligament-Deficient Knees?

Abstract

Introduction  Meniscal tears, especially in the medial meniscus, are common in anterior cruciate ligament (ACL) injuries. Repaired anterior medial portal (RAMP) lesions, specific meniscal injuries associated with ACL ruptures, affect the peripheral attachment of the posterior horn of the medial meniscus. While the relationship between femoral trochlear morphology and ACL tears is established, its association with RAMP lesions remains unexplored. This study investigates the association between femoral trochlear morphology and RAMP lesions in ACL-deficient knees using magnetic resonance imaging (MRI) and evaluates MRI's accuracy against arthroscopy. Materials and Methods  This hospital-based, cross-sectional observational study was conducted in a tertiary care center over 18 months. It included 126 adult patients who underwent arthroscopic ACL reconstruction and had preoperative MRI. Variables included age, gender, body mass index, trauma nature, and various MRI parameters, including femoral trochlear morphology and presence of RAMP lesions. MRI findings were compared to arthroscopic findings to evaluate diagnostic accuracy. Results  RAMP lesions were detected in 21 participants (16.7%) via MRI and 28 participants (22.2%) via arthroscopy. MRI showed 71.4% sensitivity and 99.0% specificity for detecting RAMP lesions. No significant association was found between femoral trochlear morphology and RAMP lesions. However, medial tibial slope (TS) and posterior medial tibial bone edema (PMTBE) were significantly associated with RAMP lesions. The agreement between MRI and arthroscopy was high (Cohen's kappa = 0.773, p < 0.001). Conclusion  This study found no significant association between femoral trochlear morphology and RAMP lesions in ACL-deficient knees. Instead, medial TS and PMTBE were significant predictors. MRI proved to have high specificity but moderate sensitivity compared to arthroscopy.