Higher incidence of osteosynthesis of proximal humerus fractures in Germany-an epidemiological study comparing osteosynthesis of the proximal humerus and shoulder arthroplasty in Germany, Austria, and Switzerland.

Background: Proximal humerus fractures (PHF) are one of the most common fractures in elderly patients, but consensus about optimal management is lacking. Conservative therapy has been recommended for elderly patients, though many countries report an increase in surgical procedures. There has also been a rapid increase in shoulder arthroplasty internationally, though large variation exists in the use of these procedures. The aim of this study was to compare the relative incidence of osteosynthesis of the proximal humerus and shoulder arthroplasty approximately over a decade in Germany, Austria, and Switzerland. Methods: National statistics databases were searched for cases of osteosynthesis of the proximal humerus (2011-2019) and shoulder arthroplasty (2009-2019) in Germany, Austria, and Switzerland. Case retrieval was based on national operation codes. National census estimates were used to calculate incidence rates per person-year. Results: The relative incidence of osteosynthesis of the proximal humerus is 1.7 times higher in Germany than in Switzerland and Austria. The relative incidence did not increase in any country between 2011 and 2019. In Germany, osteosynthesis was performed for relatively more elderly patients of ≥70 years compared to the other 2 countries and relatively more female patients compared to Austria. The relative incidence of shoulder arthroplasty increased similarly in all 3 countries between 2009 and 2019. The largest increase was seen in patients of ≥70 years; in this group the incidence more than doubled over the 10-year period in both Switzerland and Austria. Shoulder arthroplasty was more common in Switzerland for patients of ≥40 years compared to the other countries (1.8 times higher on average). Fracture endoprostheses were more common in Germany compared to Switzerland (38% vs. 23% of all shoulder arthroplasties in 2017). Germany had a higher rate of surgical management of PHF, that is, both osteosynthesis and arthroplasty as a primary management strategy. Conclusion: The overall trends of these procedures are similar in Germany, Austria, and Switzerland within the investigated period; however, some differences in surgical strategy could be identified, for example, reliance on osteosynthesis in elderly female patients with PHF in Germany.