Medial femoral condyle bone mineral density is associated with subchondral insufficiency fractures in female patients with medial meniscus posterior root tears.

Purpose: In this study, we aimed to evaluate the correlation between bone mineral density (BMD) of the medial femoral condyle (MFC) in patients with medial meniscus posterior root tears (MMPRT) and BMD at commonly evaluated sites, including the femur and lumbar spine. We also examined the association between MFC BMD and subchondral insufficiency fractures of the knee (SIFK). Methods: This retrospective cross-sectional study included patients diagnosed with MMPRT based on magnetic resonance imaging findings at our hospital between November 2025 and March 2026. Lower limb alignment, bone morphology, medial meniscus extrusion (MME) and SIFK grade were evaluated. BMD was measured at the proximal femur, lumbar spine and MFC using dual-energy X-ray absorptiometry. Spearman's rank correlation coefficient was used to evaluate the correlation between the MFC BMD and other BMD measurements. Furthermore, linear regression analysis was conducted to identify factors associated with MFC BMD. Results: A total of 47 patients were included in the final analysis. The mean age was 66.7 ± 8.2 years, and the mean body mass index (BMI) was 24.1 ± 3.9 kg/m Conclusions: MFC BMD was significantly correlated with BMD at commonly assessed regions of the proximal femur and lumbar spine in patients with early-stage osteoarthritis. Additionally, the lower MFC BMD was associated with the presence of SIFK in female patients with MMPRT. Level of Evidence: Level IV.