[Femoral neck stress fractures and femoroacetabular impingement : A retrospective case study and literature review]

Uncommon Twist: Femoral Neck Stress Fracture in a High-Performance Athlete With an Incidental Diagnosis of Femoroacetabular Impingement

Femoral neck stress fractures (FNSFs) are rare but significant injuries, often leading to delayed diagnosis due to nonspecific symptomatology. This case report presents a 30-year-old professional surfer who experienced acute groin pain during a half marathon, ultimately diagnosed with a left intertrochanteric line femur stress fracture and with femoroacetabular impingement (FAI) in the opposite hip. Despite being physically fit, his presentation challenges the prevailing notion that FNSFs predominantly occur in military personnel or the elderly. The patient underwent surgical left hip osteosynthesis without complications. This case highlights the importance of early suspicion of FNSFs in young, active individuals and emphasizes the need for comprehensive evaluation to prevent complications like osteonecrosis and malunion. It underscores the value of a broad differential diagnosis and timely intervention in optimizing outcomes, especially in the context of rising high-impact sports participation.

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

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.

[Stress fractures of the lower limbs]

Stress reactions and fractures represent an important differential diagnostic entity, especially in patients active in sports. The lower extremities have predilection sites for stress fractures, which require special treatment in the context of the underlying risk factors. Clinically, patients usually complain of stress-dependent pain in the affected region and sport activities are mostly limited or even impossible. The detection of acute stress fractures is usually missed by conventional X‑ray within the first 4-6 weeks. The gold standard diagnostic tool is magnetic resonance imaging (MRI). Depending on the location, a distinction must be made between low-risk and high-risk stress fractures. Low-risk fractures show a high healing rate after conservative treatment including load and stress reduction as well as avoiding risk factors. High-risk fractures can take a complicated course under conservative treatment measures and in some cases, surgical intervention is required.