Association of knee osseous morphometric parameters with degeneration and tear of the discoid lateral meniscus: a...

Discoid lateral meniscus (DLM) is a congenital knee variant prone to degeneration and tears owing to its unique morphology and altered biomechanics. While magnetic resonance imaging (MRI) is the gold standard for DLM evaluation, the anatomical contributors to its pathological progression remain unclear. This study aimed to explore MRI-based morphological factors associated with DLM degeneration and tears using quantitative analysis.

A total of 292 patients with DLM were retrospectively divided into three groups based on MRI findings: normal, degenerative, and tear DLM. Quantitative morphometric measurements of knee bony structures were acquired, including fibular head height, tibial spine height, anteroposterior (AP) diameter, width, and height of the medial and lateral femoral condyles, as well as the AP diameter and width of the medial and lateral tibial plateaus. Statistical analyses were performed to explore the associations between these morphological parameters and DLM pathological grading.

There were significant differences in osseous morphometric MRI parameters between meniscus grading groups. Significant differences were found in fibular head height, medial tibial spine height, width of lateral femoral condyle, medial and lateral femoral condyle heights, AP diameters of the medial and lateral tibial plateau, and medial tibial plateau width between groups (P<0.05). The medial tibial plateau AP diameter [odds ratio (OR) 1.37, 95% confidence interval (CI): 1.22-1.55, P<0.001] and fibular head height (OR 1.31, 95% CI: 1.12-1.53, P<0.001) were independent predictors of DLM tears. The medial tibial plateau AP diameter showed superior diagnostic ability [area under the curve (AUC) 0.856, 95% CI: 0.807-0.906], followed by fibular head height (AUC 0.846, 95% CI: 0.792-0.900). The combined model yielded a higher diagnostic value (AUC 0.973, 95% CI: 0.954-0.991).

Several bony morphological features of the knee, especially the AP diameter of the medial tibial plateau, are associated with an elevated risk of DLM degeneration and tears. These findings may facilitate early risk stratification and clinical decision-making.