Incidence of Osteoporotic Refractures Following Proximal Humerus Fractures in Adults Aged 50 Years and Older in Korea

BACKGROUND: The purpose of this study was to investigate the incidence and characteristics of osteoporotic refractures after proximal humerus fracture in Korean adults aged above 50 years. METHODS: Patients aged 50 years or older with initial proximal humerus fractures reported in 2012 were enrolled and followed up until 2016 using the Korean National Health Insurance data. Based on the last claim date, the refractures were classified as osteoporotic fractures including spine, hip, distal radius, and humerus 6 months after the index fracture involving the proximal humerus. Each osteoprotic fracture was identified using specific International Classification of Diseases, 10th Revision codes and site-specific physician claims for procedures. RESULTS: A total of 5,587 first-time fractures involving proximal humerus were reported in 2012. Among them, a total of 1,018 osteoporotic refractures occured between 2012 and 2016. The total cumulative incidence of osteoporotic refractures was 4.85% (271/5,587) at 1 year, 9.61% (537/5,587) at 2 years, 14.21% (794/5,587) at 3 years, and 18.22% (1,018/5,587) at 4 years. In terms of site by year, the incidence of associated refractures was as follows: spine, 48.62% (495/1,018); hip, 25.83% (263/1,018); wrist 18.57% (189/1,018); and humerus 6.97% (71/1,018) during all the follow-up periods. CONCLUSIONS: Our study showed that the cumulative incidence of osteoporotic refractures following proximal humerus fractures in the elderly population has been increasing over the years. Given that osteoporotic refractures are associated with an increased mortality risk, a public health strategy to prevent the refracture after proximal humerus fracture in the elderly is imperative.