It is unclear if clinical recovery following a midshaft clavicle fracture can accurately predict fracture-healing. Assessment at 6 weeks after injury may have superior predictive value.

A new study published in The Journal of Bone and Joint Surgery aimed to ascertain whether delayed assessment at 6 weeks after a midshaft clavicle fracture can accurately predict fracture-healing.

This was a prospective study of all patients above the age of 16 years, who sustained a fully displaced midshaft clavicle fracture. Conditional stepwise regression modelling was used to assess which factors independently predicted nonunion at 6 months after the injury, as determined by computed tomography (CT).

Overall, 200 patients completed follow-up at 6 months. The results showed that :

• CT-defined nonunion rate was 14%.
• Of the functional scores, the QuickDASH had the highest accuracy on receiver operator characteristic (ROC) curve analysis with a 39.8-point threshold—above which was associated with nonunion (AUC), 76.8%.
• Overall, 69% of the cohort had a QuickDASH score of <40 points at 6 weeks, and 95% of these patients had fracture union.
• On regression modeling, a QuickDASH score of ≥40 points – no callus on radiographs and fracture movement on examination were significant predictors of nonunion.
• If none of the predictors were present, the predicted nonunion risk was 3%, found in 40% of the cohort.
• On the contrary, if ≥ 2 were present—found in 23.5% of the cohort—the predicted nonunion risk was 60%.
• Furthermore, the nonunion predictor model at 6 weeks appeared to have superior accuracy—AUC, 87.3%, when compared with the nonunion predictor model at the time of injury—AUC, 64.8%, for fracture-healing on ROC curve analysis.

From the findings, it was concluded that delayed assessment at 6 weeks following displaced midshaft clavicle fracture enables an accurate prediction of patients who are likely to have union with nonoperative management. Moreover, one in four patients are at an increased risk of nonunion and may benefit from operative intervention.

Source: The Journal of Bone and Joint Surgery. 2020 Jan 22. doi: 10.2106/JBJS.19.00955