Does Shortening Change in the First 2 Weeks Following Completely Displaced Adolescent Clavicle Fractures?

BACKGROUND: Shortening of midshaft clavicle fractures has been described as a critical fracture characteristic to guide treatment in clavicle fractures. However, the degree to which shortening may actually change in the weeks following injury has not been well studied. PURPOSE: The purpose of this study was to evaluate the potential change in shortening of adolescent clavicle fractures in the first 2 weeks following injury. METHODS: This was an IRB-approved multi-center study of prospectively collected data which was acquired as a part of a larger cohort study evaluating functional outcomes of adolescent clavicle fractures. A consecutive series of patients ages 10 – 18 years of age with completely displaced diaphyseal clavicle fractures with a baseline AP clavicle radiograph (0-6 days from date of injury) and a follow-up AP clavicle radiograph (7 – 21 days from date of injury) were included. Measurements of end-to-end clavicle shortening were performed with validated techniques. RESULTS: 142 patients met inclusion criteria. Baseline radiographs were obtained at a mean of 1 day +/- 1.7 days following injury. Mean baseline shortening was 22.3mm +/- 0.6mm. 69% of patients had >/= 20mm of shortening. Follow-up radiographs were obtained at a mean of 13.8 days +/- 3.8 days post-injury and demonstrated a mean change in shortening of 5.4mm, compared to baseline films. 41% of patients had >5mm of change in shortening and 15% of patients had >10mm change in shortening. Using a threshold shortening of 20mm, 26% of patients had a change from baseline to follow-up from either above to below 20mm or below to above 20mm. This includes 28% of patients with 20-25mm of shortening at baseline that were less than 20mm at follow-up. CONCLUSION: Significant changes in fracture shortening occur in many adolescents with completely displaced clavicle fracture in the first 3 weeks. More than a quarter of patients demonstrated a drop from above to below 20mm, a commonly used threshold for surgical decision making. While there is minimal evidence to suggest that shortening influences outcomes following this fracture in adolescent sub-populations, the findings of this study support repeat radiographic assessment 2-3 weeks post-injury prior to making definitive treatment decisions.