Abstract. Objectives. We aimed to evaluate if union of clavicle fractures can be predicted at six weeks post-injury by the presence of bridging callus detected by ultrasound. Methods. Adult patients who sustained a displaced midshaft clavicle were recruited prospectively. We assessed patient demographics, functional scores and radiographic predictors with a standardized protocol at six weeks. Ultrasound evaluation of the fracture site was undertaken to determine if sonographic bridging callus was present. Nonunion was determined by CT scanning at six months post-injury. Clinical features at six weeks were used to stratify patients at high risk of nonunion and a QuickDASH ≥40, fracture movement on examination or absence of callus on radiograph. Results. 112 patients completed follow-up at six months with a nonunion incidence of 17% (n=18/112). Sonographic bridging callus was detected in 62.5% (n=70/112) of the cohort at six weeks post-injury. If present, union occurred in 98.6% of the fractures (n=69/70). If absent, nonunion developed in 40.5% of cases (n=17/42). The sensitivity to predict union with sonographic bridging callus at six weeks was 73.4% and the specificity was 94.4%. Regression analysis found failure to detect sonographic bridging callus at six weeks was associated with nonunion, older age, female sex, and greater overall fracture displacement (Nagelkerke R2=0.60). Of the cohort, 30.4% (n=34/112) had absent sonographic bridging callus at six weeks in combination with one or more of the ‘high risk’ clinical features. If one was present the nonunion rate was 47.1%, increasing to 60% with two risk factors and 100% when combined with all three. Conclusions. Ultrasound can accurately predict fracture healing at six weeks following a
Background. Clavicle development occurs before the age of 9 in females and 12 in males. Children below the age of 10 with