Changes in superior displacement, angulation, and shortening in the early phase of healing for completely displaced midshaft clavicle fractures in adolescents: results from a prospective, multicenter study

Background: Progressive displacement of diaphyseal clavicle fractures has been observed in adult patients, at times necessitating a change from nonoperative to operative treatment. Whether this occurs in adolescent patients has not been well investigated. The purpose of this study was to assess the rate and extent of progressive clavicle fracture displacement in adolescent patients following injury and during the early stages of healing. Methods: This was a multicenter study evaluating prospective data that had previously been collected as part of a larger study evaluating the functional outcomes of adolescent clavicle fractures. A consecutive series of completely displaced diaphyseal clavicle fractures in patients aged 10-18 years treated at 1 of 3 tertiary-care pediatric trauma centers was included; all fractures underwent standardized imaging within 2 weeks of the date of injury and during the course of healing (5-20 weeks after injury). Measurements of clavicle shortening, superior displacement, and angulation were performed using validated techniques. Progressive displacement and/or interval improvement in fracture alignment, as well as the subsequent need for surgical intervention, was noted. Patient demographic and radiographic parameters were assessed as possible risk factors for interval displacement. Results: One hundred patients met the inclusion criteria. Mean end-to-end shortening, cortex-to-cortex shortening, superior displacement, and angulation at the time of injury were 24 mm, 15 mm, 15 mm, and 7°, respectively. At a mean of 10 weeks after injury, the fracture alignment improved across all 4 measurements for the overall cohort, with mean improvements of 3.5 mm in end-to-end shortening, 3.3 mm in cortex-to-cortex shortening, 2.1 mm in superior displacement, and 2° in angulation. By use of a clinical threshold of a change in shortening or displacement of 10 mm or change in angulation of 10°, 26% of fractures improved, 4% worsened, and 70% remain unchanged. Patients with more severe fractures were more likely to have improved alignment than were patients with less displaced fractures (P < .001). No patient underwent surgical intervention for progressive displacement. Conclusion: Significant early improvements in fracture alignment were observed in a substantial percentage of adolescent patients with completely displaced clavicle fractures. Among the most severely displaced fractures, shortening improved approximately 6 mm and angulation improved approximately 9°. In 4% of cases, increased displacement was observed, but this tended to be mild, and in no cases did it prompt surgical intervention. This finding indicates that the true final deformity after an adolescent clavicle fracture is commonly less than that present at the time of injury.