Association between thoracic inlet diameter ratio and clavicle fractures: A case-control study.

BACKGROUND

Clavicle fractures account for 2-10 % of skeletal injuries, often resulting from lateral shoulder falls (87 % of cases), and are common in pediatric and young adult populations. Despite their clinical importance, the role of anatomical factors like thoracic inlet dimensions in fracture risk is poorly understood.

METHODS

This STROBE-compliant case-control study evaluated the association between thoracic inlet measurements-anterior-posterior (AP) diameter, transverse diameter, and area-and clavicle fracture risk, with secondary analyses by age, sex, and BMI.

RESULTS

We studied 27 patients with clavicle fractures and 53 matched controls (aged 18-65 years) who underwent chest CT evaluation for suspected clavicle fracture following upper chest trauma but were confirmed to have no fracture; their CTs were then used for thoracic inlet measurements. Statistical analyses compared AP diameter, transverse diameter, and transverse/AP ratio between groups. The fracture group showed a significantly larger AP diameter (5. 80 ± 0.90 cm vs. 5. 34 ± 0.77 cm, p = 0.0181) and a significantly lower transverse/AP ratio (1. 88 ± 0.31 vs. 2. 08 ± 0.39, p = 0.025) than controls, suggesting a relatively broader, narrower inlet shape is associated with fractures. Transverse diameter (10. 68 ± 1.15 cm vs. 10. 85 ± 0.93 cm, p = 0.424) and inlet area (59. 15 ± 10.60 cm² vs. 57. 84 ± 9.34 cm², p = 0.5742) were similar between groups. Subgroup analyses indicated stronger differences in males (e.g., transverse/AP ratio: 1. 77 ± 0.33 vs. 2. 09 ± 0.40, p = 0.005) and those with BMI <23 kg/m ² (e.g., transverse/AP ratio: 1. 69 ± 0.39 vs. 2. 14 ± 0.42, p = 0.007).

CONCLUSIONS

We conclude that increased AP diameter and reduced transverse/AP ratio of the thoracic inlet may elevate clavicle fracture risk, highlighting anatomical influences on susceptibility. Further biomechanical and preventive studies are needed.