Anterior acetabular sector angle is a potential indicator for identifying subchondral fatigue fracture of the femoral head in young military recruits

Abstract

Purpose This study aimed to evaluate the intrinsic risk factors for SFFFH in young military recruits. Methods We retrospectively analyzed 98 SFFFH and 24 ONFH patients who were affiliated with the Chinese People's Liberation Army (PLA) between 2013 and 2019. X-ray and MRI were the main data for analysis. Acetabular anteversion of the superior acetabulum (AVsup), acetabular anteversion of the center of the acetabulum (AVcen), anterior acetabular sector angle (AASA), posterior acetabular sector angle (PASA), superior acetabular sector angle (SASA), neck-shaft angle (NSA), inferior iliac angle (IIA) and ischiopubic angle (IPA) were calculated by two observers with three times. Then, logistics regression and independent samples T-test were performed to analyze the above data to explore the risk factors of SFFFH. Results Based on the results of logistics regression, age (OR: 1.33; 95% CI: 1.12-1.65; P-value = 0.0031) could be considered as the indicator. AVcen (P-value = 0.0334), AASA (P-value = 0.0002), NSA (P-value = 0.0007), IIA (P-value = 0.0316) were considered to be statistical significance. Further, AVcen (OR: 1.41; 95% CI: 1.04-1.95) and AASA (OR: 1.44; 95% CI: 1.21-1.77) especially AASA (area under curve: 66.6%) should be paid much more attention. Conclusions We unveiled that AASA could be the key factor for SFFFH, which further verified that deficient anterior coverage of the acetabulum might be the main cause of SFFFH.