Correlation between tibial eminence fractures and morphology of femur condyles and tibial slopes in male patients: a retrospective case-control study.

BACKGROUND: Several studies have examined the relationship between anterior cruciate ligament (ACL) injury and the femoral condyle and tibial slopes. Tibial eminence fractures (TEFs) are often noted during the diagnosis and treatment of patients with ACL injuries. However, only a few studies have investigated the relationship between anatomic parameters of the knee and TEFs in adults. Therefore, we aimed to investigate the link between TEFs and the shape of the femoral condyles and tibial slopes. METHODS: Patients who underwent surgery were identified using the hospital's electronic medical record system from May 2013 to May 2023. Three sex-, age-, and BMI-matched cohorts (n = 20 each) were included: the TEF, ACL injury, and control groups. The femoral condylar width (epicondylar width [EW]), intercondylar notch width (ICW), notch width index (NWI), intercondylar notch height, morphological index of the intercondylar notch (NSI), intercondylar notch angle (ICA), and "α" angle were measured using axial MRI. The medial and lateral tibial slopes were measured using sagittal MRI to compare differences among the TEF, ACL injury, and control groups. Multiple logistic regression analysis was performed to identify independent predictors of TEFs. RESULTS: We found no significant differences in age, height, weight, and body mass index between the TEF and ACL injury groups (P > 0.05). No significant differences were noted in the ICW, EW, NWI, "α" angle, or medial tibial slope among the TEF, ACL injury, and control groups (P > 0.05). The NSI differed significantly between the ACL injury and control groups (P < 0.05). The ICA in the ACL injury group was significantly lower than that in the control group (P < 0.05). The lateral tibial slope (LTS) was significantly greater in the TEF group than in the ACL injury group (P < 0.05). Logistic regression analysis and odds ratio estimates showed that LTS is an important risk factor for TEFs. The area under the curve of the LTS was 0.714, with a sensitivity of 70.00% and specificity of 70.00%; thus, it was the best anatomical angle for identifying patients prone to TEFs. CONCLUSION: Our results suggest that a narrow femoral intercondylar notch contributes to ACL injuries, while TEFs are closely related to tibial plateau morphology. TEFs should be regarded as a specific type of tibial plateau fracture rather than a specific pattern of ACL injury.