Medial and Lateral Meniscus Root Tear: Etiopathogenesis and Morphological Pattern in Indian Population

Objective: This study aims to enhance our understanding of the morphological pattern, causes and pathogenesis of meniscal root injuries in the Indian population.

Materials and methods: Sixty-four patients with meniscus root tears were included in the study. The patients were categorized into two groups based on the location of the meniscus tear: Group 1 (n = 41) comprised patients with lateral meniscus root injury (LMRI), and Group 2 (n = 23) included patients with medial meniscus root injury (MMRI). Demographic and patient-specific data, such as age, gender, BMI, history of injury, and injury type, were recorded. All patients underwent surgical treatment, and intraoperative findings (chondral damage grade, type of root injury, associated ligamentous injuries) were documented. Meniscus root tears are further classified into 5 categories depending upon their morphological types. A minimum 12-month follow-up assessed functional outcomes using the Lysholm and IKDC knee scores.

Results: The mean age for MMRI and LMRI was 50.3 years and 29.4 years, respectively. In the MMRI group, 48% (11/23) were female compared to only 15% (6/41) in the LMRI group. The mean BMI in the MMRI and LMRI groups was 30.1 and 25.4, respectively. Nine patients in MMRI and 4 patients in LMRI group exhibited grade 3 or higher chondral damage. Type 2 meniscus root tear was most common type in both the groups (51% in MMRI vs. 74% in LMRI). Both LMRI and MMRI groups demonstrated significant improvement in functional outcomes.

Conclusions: Medial meniscus root injuries predominantly occur in the elderly without a significant history of trauma, often associated with a high grade of medial femoral chondral damage, suggesting a degenerative etiology. In contrast, lateral meniscus root injuries tend to occur in younger patients with a notable history of knee injury, indicative of a traumatic etiology for LMRI.