Impact of Femorotibial Displacement and Congruence on Posterior Horn Medial Meniscal Tears: An MRI Assessment
Chao Liu, YuNan Hu, Hejun Sun, QianJiang Xiong, Tianhao Xu, Jian Li, Qinghong Xia, WeiLi FuBackground:
The anatomical relationship between the medial femoral condyle (MFC) and medial tibial plateau (MTP) is crucial for knee biomechanics. However, the influence of their relative displacement and congruence on the loading of the posterior horn of the medial meniscus (PHMM) remains poorly understood.
Purpose:
To evaluate the relationship of the relative displacement and congruence between the MFC and MTP on PHMM tears using magnetic resonance imaging (MRI) and to assess the diagnostic value of these parameters.
Study Design:
Cross-sectional study; Level of evidence, 3.
Methods:
A retrospective review was conducted on patients who were evaluated for knee pain and underwent MRI between January 2020 and January 2025. The cohort comprised 112 patients with arthroscopically confirmed horizontal tears of the PHMM and 82 age- and sex-matched controls with normal medial menisci. Demographic and clinical characteristics were collected from both groups. Multiple coronal MRI parameters were measured, including the MFC displacement ratio (MFCDR), MFC ratio (MFCR), lateral tibial plateau displacement ratio (LTPDR), lateral femoral condylar ratio, femoral intercondylar ratio (FIR), and tibial intercondylar ratio (TIR). Variables significant in univariate analysis were entered into a multivariate logistic regression model to identify independent risk factors. Receiver operating characteristic (ROC) curve analysis was used to determine diagnostic performance and optimal cutoff values.
Results:
The 2 groups were comparable in baseline characteristics, including age, body mass index, sex, affected side, comorbidities, Kellgren-Lawrence grade, and varus angle (all
Conclusion:
PHMM horizontal tears are significantly associated with increased coronal plane displacement, reduced bony congruence, and altered intercondylar morphology on MRI. MFCDR, LTPDR, FIR, and TIR are independent structural features associated with this condition, and the combination of MFCDR and LTPDR offers favorable diagnostic utility for identifying patients with these injuries.