Relationship of Medial Meniscus Posterior Root Tears with Proximal Tibial Morphology and Knee Osteoarthritis

Purpose: To investigate the relationship between proximal tibial morphology (PTM) and medial meniscus posterior root tears (MMPRT), and to evaluate the association between medial meniscal extrusion amount (MMEA) and osteoarthritis (OA) in patients with MMPRT. Material and method: This retrospective study analyzed knee MRIs of 100 patients with MMPRT and 100 age, gender, side paired controls. Medial posterior tibial slope angle (MPTSA), mediolateral length (MLL), medial anteroposteiror width (MAW), lateral anteroposteiror width (LAW), were used to evaluate PTM . MMEA and tear gap (TG) correlation and their relationship with knee OA severity was assessed. Results: MPTSA was significantly higher in MMPRT group compared to controls (p<0.001). Moderate positive correlation was found between MMEA and OA severity (R ² =0.445, p<0.001). Cartilage loss was observed when MMEA exceeded 4 mm (sensitivity: 80.68%; specificity: 83.33%). MMEA increased by 1.10 mm for each 1 mm increase in TG. Conclusion: This groundbreaking study reveals that steeper medial tibial plateau is a significant risk factor for MMPRT. Strikingly, MMEA exceeding 4 mm serves as a critical threshold for cartilage loss, potentially revolutionizing treatment decisions. These findings not only enhance our understanding of MMPRT pathomechanics but also provide crucial insights for early intervention strategies, potentially altering the course of OA progression in patients with MMPRT.