Prevalence of non-union and delayed union in proximal humeral fractures.

Background: Little is known about the prevalence of proximal humeral non-union. There is disagreement on what constitutes union, delayed union and non-union. Our aim was to determine the prevalence of these complications in proximal humeral fractures (PHFs) admitted to trauma hospitals.

Methods: The Victorian Orthopaedic Trauma Outcomes Registry identified 419 cases of PHFs, of which 306 were analysed. Three upper limb orthopaedic surgeons used X-rays to classify fractures according to the Neer classification and determine union. Twelve-item Short Form Health Survey scores were used to assess patient health and wellbeing.

Results: Of 306 cases, 49.4% reached union. Median time to union was 100 days (confidence interval 90-121). Of these, 17.0% united by 60 days, 8.5% united by 89 days and 23.9% united after 90 days, demonstrating 'prolonged delayed union'. There were 25 non-unions with a prevalence of 8.2%, most occurring in two-part surgical neck fractures.

Conclusion: Our cohort of largely displaced PHFs admitted to trauma hospitals had a non-union prevalence of 8.2% and an overall delayed union prevalence of 32.4%. Consensus is required on definitions of non-union and delayed union timeframes.