Upright vs. Supine Radiographs of Clavicle Fractures: Does Positioning Matter?
ABSTRACT To determine if clavicle fracture displacement and shortening are different between upright and supine radiographic examinations.
Combined retrospective and prospective comparative study.
Level I Trauma Center PATIENTS:: Forty-six patients (mean age 49 years, range 24-89 years) with an acute clavicle fracture were evaluated.
Standardized clavicle radiographs were obtained in both supine and upright positions for each patient. Displacement and shortening were measured and compared between the two positions.
One resident and three traumatologists classified the fractures and measured displacement and shortening. Data was aggregated and compared to ensure reliability with a two-way mixed intraclass correlation (ICC).
Fracture displacement was significantly greater when measured from upright radiographs (15.9±8.9mm) than from supine radiographs (8.4±6.6mm, p<0.001), representing an 89% increase in displacement with upright positioning. Forty-one percent of patients had greater than 100% displacement on upright, but not on supine radiographs. Compared to the uninjured side, 3.0±10.7mm of shortening was noted on upright radiographs and 1.3±9.5mm of lengthening on supine radiographs (p<0.001). The ICC was 0.82 (95% CI: 0.73-0.89) for OTA fracture classification, 0.81 (95% CI: 0.75-0.87) for vertical displacement, and 0.92 (95% CI: 0.88-0.95) for injured clavicle length, demonstrating very high agreement among evaluators.
Increased fracture displacement and shortening was observed on upright compared to supine radiographs. This suggests that upright radiographs may better demonstrate clavicle displacement and predict the position at healing if nonoperative treatment is selected.