Introduction: Humeral shaft fractures account for 1–3% of all fractures. Little is known about additional epidemiological data on this specific fracture type. The aim of this study was to investigate the epidemiology of humeral shaft fractures in patients 16 years or older in Stockholm during the years 1998–99.

Patients and Methods: All patients 16 years or older with a humeral shaft fracture admitted to any of six major hospitals in the County of Stockholm during the two years 1998–99 were included in the study. A total of 401 fractures in 397 patients were found. Three hundred and sixty-one of the fractures were traumatic and were classified according to the Orthopaedic Trauma Association (OTA) classification system. The remaining 40 fractures were pathological (n=34) or peri-implant fractures (n=6). Open fractures were classified using the Gustilo classification system. Data regarding the injury mechanism, age, gender, side of the injury and occurrence of possible radial nerve injury were collected from the medical charts. The overall incidence and the age-specific incidence were calculated on the basis of data from Statistics Sweden.

Results: The incidence was 14.5 per 100 000 persons per year with a gradually increasing age-specific incidence from the fifth decade in both genders and reaching an incidence of almost 60 per 100 000 persons and year in the ninth decade. The majority of fractures were closed ones sustained after simple falls among elderly patients. The age distribution among females was characterised by a peak in the eighth decade while the age distribution among males was more even. Type A (simple) fractures were by far the most common and the majority of the fractures were located in the middle and proximal parts of the humeral shaft. The incidence of radial palsy was 8%. Fracture localisation in the middle and distal part of the shaft was associated with an increased risk for having radial nerve palsy. Only 2% of the fractures were open and 8% were pathological.

Discussion: These recent epidemiological data on humeral shaft fractures are representative of a society with a limited amount of high-energy trauma, including penetrating trauma, which probably reflects the situation in the majority of European countries. Our results can be used to facilitate the future treatment of patients with this particular fracture.