Proximal Humeral Fractures in Finland - Regional Differences in Incidence and Methods of Treatment.

Background: Proximal humeral fractures (PHF) are one of the most common fragility fractures and there is accumulating evidence that even displaced PHFs should be treated conservatively. The treatment should be as effective and standardized as possible regardless of the hospital district of the patient. The aim of this study was to describe possible regional variation in incidence and treatment methods of PHFs in Finland.

Methods: The study included all Finnish inhabitants aged 16 years and older with PHF diagnosis between 1997 and 2019. All records are based on data from two national registers. The fractures and operations were organized according to hospital district of the patient and annual incidences of PHFs, and different treatment methods were calculated for each hospital district.

Results: Between 1997 and 2019, 79,053 PHFs were identified. 64,117 of PHFs were treated conservatively and 14,936 operatively. The incidence of conservative treatment corresponded closely to the fracture incidence per hospital district. Internal fixation (IF) incidence generally increased towards the end of the first half of the study period and declined thereafter, and hemiarthroplasty (HA) was replaced by total shoulder arthroplasty (TSA) as the most common type of arthroplasty by the end of the period. We found regional variation in the incidence of PHFs, with a low of 61.4 per 10⁵ in Åland, and a high of 97.7 per 10⁵ in East-Savo.

Conclusions: In Finland, the treatment of PHFs did not differ fundamentally between hospital districts and a general evidence-based shift in treatment practice was shown. We found regional variation in the incidence of PHFs, and it seems that the higher incidence of PHFs is concentrated in the Eastern Finland.