Medial Meniscus Posterior Root Notch Angle and Lateral Tibial Plateau Morphology Are Associated with Medial Meniscus Posterior Root Tears

Abstract Purpose This study aimed to identify the associations of MMPRNA, tibial lateral anteroposterior dimension (TLAPD), and aspect ratio of the lateral tibial plateau (ARLTP) with MMPRT. Methods This retrospective case-control study included 95 patients with complete MMPRT and 95 matched controls with knee pain but no pathological meniscal changes on MRI. MRI measurements included the MMPRNA, tibial mediolateral dimension (TMLD), tibial medial anteroposterior dimension (TMAPD), and TLAPD. The aspect ratio of the medial tibial plateau (ARMTP) and ARLTP were calculated. Measurements were compared between the experimental and control groups. Receiver operating characteristic (ROC) curve analysis was used to determine the area under the curve (AUC), maximum Youden index, sensitivity, specificity, and optimal cutoff values for variables showing significant differences. Results No significant differences in demographic characteristics, Kellgren-Lawrence (K-L) grade, TMLD, TMAPD, and ARMTP were observed between the two groups (P > 0.05). The MMPRNA was significantly smaller in the MMPRT group than in the control group(MMPRT group mean: 125.9°±22.6°; control group mean: 138.9°±16.1°; P < .001), as was the TLAPD (MMPRT group mean: 39.5 ± 3.9 mm; control group mean: 42.4 ± 3.8 mm; P < .001). In contrast, the ARLTP was significantly greater in the MMPRT group (MMPRT group mean: 1.8 ± 0.2; control group mean: 1.7 ± 0.1; P < .001). ROC analysis identified an optimal MMPRNA cutoff of 144.66°, with a sensitivity of 81.1%, a specificity of 46.3%, and an AUC of 0.67. The optimal ARLTP cutoff was 1.76, yielding a sensitivity of 56.8%, a specificity of 85.3%, and an AUC of 0.73. For TLAPD, the optimal cutoff was 39.21 mm, with a sensitivity of 45.3%, a specificity of 85.3%, and an AUC of 0.70. Conclusions Smaller MMPRNA and TLAPD, as well as larger ARLTP, are closely associated with the MMPRT.