Gender-Based Analysis of the Ratio of Femoral Condyle Depth and Intercondylar Notch Depth to the Intercondylar Surface for Femoral Intercondylar Notch anatomy Using MRI Images: Implications for Anterior Cruciate Ligament Injury Risk

Abstract Purpose Anterior cruciate ligament (ACL) rupture is a common injury, particularly in athletes. Recent studies have suggested a potential association between femoral intercondylar notch geometry and ACL injury risk. Understanding the anatomical differences in the intercondylar notch between the sexes may help explain the higher incidence of ACL injuries in women. Magnetic resonance imaging (MRI) allows evaluation of the femoral intercondylar notch and ACL geometry. Methods We measured four different geometric indices of the distal femur using axial PD fast spin echo MRI imaging. These indices included the maximum intercondylar notch width to femoral condyle width (NWI), the ratio of intercondylar notch shape index (NSI), the total articular surface area of the inferior femoral area (NAI), and the ratio of femoral condyle depth to intercondylar notch depth (NDI). Results In this retrospective study, we evaluated the femoral intercondylar notch geometry in 136 patients (81 males, 55 females) using cross-sectional MRI. The mean values for NWI, NSI, NAI, and NDI were 0.27 ± 0.03 mm and 0.25 ± 0.04 mm, 0.73 ± 0.06 mm and 0.68 ± 0.07 mm, 0.12 ± 0.02 mm and 0.10 ± 0, 01 mm, and 0.45 ± 0.02 mm and 0.47 ± 0.01 mm for men and women, respectively. Notably, the NDI index was deeper in women than in men. Conclusion Our findings suggest that women have a deeper NDI index, indicating potentially greater pressure on the ACL and increased susceptibility to injury. By gaining a better understanding of the anatomical differences between men and women, we can develop more effective prevention strategies to reduce the risk of ACL injuries, particularly in female athletes.