Epidemiology of 936 humeral shaft fractures in a large Finnish trauma center

Humeral shaft fractures are relatively common injuries and are classified according to location and fracture morphology. Epidemiological studies improve understanding of injury patterns and lay foundations for future research. There are only a few published larger epidemiological studies on humeral shaft fractures.We retrospectively analyzed the medical records of adult patients having sustained a humeral shaft fracture treated in the Helsinki University Hospital between 2006 and 2016. We recorded patient and fracture characteristics, timing and mechanism of injury, associated injuries, and 1-year mortality.We identified 914 patients (489 females, median age = 61.4 years; 425 males, median age = 50.4 years) with 936 fractures. Over 60% of these fractures were sustained from simple falls. The patient age distribution was bimodal, with highest fracture rates in elderly females and young males. We divided the fractures into typical traumatic, periprosthetic, and pathological fractures. Of the 872 typical traumatic fractures, 3.0% were open. In addition, there were 24 (2.6%) periprosthetic and 40 (4.3%) pathological fractures. An associated injury was found in 24% of patients, with primary radial nerve palsy (PRNP) being the most common (10%). PRNPs were more common in distal shaft fractures and high energy injuries. The 1-year mortality was 9.2%.In this study, the most common injury mechanism was a simple fall. The most common associated injury was PRNP. The observed bimodal fracture distribution is consistent with previous literature.