Scoring of radiographic cortical healing with the radiographic humerus union measurement predicts union in humeral shaft fractures

PurposeThe purpose of this study is to determine if the radiographic humerus union measurement (RHUM) is predictive of union in humeral shaft fractures treated nonoperatively.MethodsAll patients with long bone fracture nonunion presenting to a single surgeon were enrolled in a prospective registry. This registry was queried to identify patients with humeral shaft fractures treated nonoperatively and developed nonunion. The nonunion cohort was matched to a three to one gender- and age-matched control group that were treated nonoperatively for a humeral shaft fracture and achieved union. Two fellowship-trained orthopedic traumatologists blinded to eventual union scored radiographs obtained 12 weeks after injury using the RHUM. A binomial logistic regression determined the effect of the RHUM on the likelihood of developing union.ResultsNine patients with humeral shaft fractures treated nonoperatively with radiographs 12 weeks after injury that developed nonunion were identified. These patients were matched to 27 controls. Logistic regression demonstrated the RHUM was a significant predictor of healing 12 weeks after humeral shaft fracture treated nonoperatively (p=0.014, odds ratio 9.434, 95% CI for OR 1.586-56.098). All patients with RHUM below 7 went on to nonunion. All patients with RHUM above 8 healed. Three of seven patients (43%) with RHUM of 7 or 8 healed.ConclusionThe RHUM demonstrated an increased likelihood of achieving union 12 weeks after injury. Orthopedic surgeons can counsel patients that fractures with RHUM scores of 6 or below are in danger of developing nonunion and can target interventions appropriately.