Subchondral fatigue fracture of the femoral head in young military recruits: Potential risk factors

Abstract

BACKGROUND

Subchondral fatigue fracture of the femoral head (SFFFH) mainly occurs in young military recruits and might be confused with osteonecrosis of the femoral head. However, less research focuses on the risk factor for SFFFH.

AIM

To evaluate the intrinsic risk factors for SFFFH in young military recruits.

METHODS

X-ray and magnetic resonance imaging data were used for analysis. Acetabular anteversion of the superior acetabulum, acetabular anteversion of the center of the acetabulum (AVcen), anterior acetabular sector angle (AASA), posterior acetabular sector angle, superior acetabular sector angle, neck-shaft angle (NSA), inferior iliac angle (IIA), and ischiopubic angle were calculated. Then, logistic regression, receiver operating characteristic curve analysis, and independent samples t-test were performed to identify the risk factors for SFFFH.

RESULTS

Based on the results of logistic regression, age [odds ratio (OR): 1.33; 95% confidence interval (95%CI): 1.12-1.65; P = 0.0031] and treatment timing (OR: 0.86; 95%CI: 0.75-0.96; P = 0.015) could be considered as the indicators for SFFFH. AVcen (P = 0.0334), AASA (P = 0.0002), NSA (P = 0.0007), and IIA (P = 0.0316) were considered to have 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 due to the higher OR than other indicators.

CONCLUSION

We have for the first time unveiled that AASA and age could be key risk factors for SFFFH, which further verifies that deficient anterior coverage of the acetabulum might be the main cause of SFFFH.

Keywords: Subchondral fatigue fracture of the femoral head; Age; Anterior acetabular sector angle; Risk factors

Core Tip: Our findings indicate that a small anterior acetabular sector angle (AASA) indicates poor anterior coverage of the femoral head and can increase the risk of subchondral fatigue fracture of the femoral head (SFFFH) in young patients. Since patients with a history of intense military training may be at higher risk for SFFFH, early detection and appropriate management are crucial to prevent further deterioration of the femoral head and preserve joint function. Based on these findings, we, therefore, recommend orthopedic surgeons not to exclude the possibility of SFFFH in patients who present with hip pain and have a history of intense military training, particularly if they have a small AASA.