gms | German Medical Science

Background: Osteoporosis-associated fractures are responsible for the loss of more than one million quality-adjusted life years and costs of more than 37 billion euros in Europe each year. Despite a clearly indicated therapy after index fracture, guideline-based treatment is rarely implemented, described as the Osteoporosis Treatment Gap in the literature. The aim of this work was to evaluate the effect of pharmaceutical osteoporosis therapy on the risk of the occurrence of other osteoporosis-associated fractures (OAF) after sustaining a proximal humerus fracture (PHF).

Materials and Methods: Health insurance data from N=43,310 (median age 79 years, 84% women) statutorily insured PHF patients aged 65 years and older with surgical therapy in 01/2013 – 09/2019, were retrospectively analysed. Within 5 years of pre- and up to 6 years of follow-up period, previous and subsequent OAF were analysed. Event rates were represented using multi-state models and calculated accordingly using Nelson-Aalen or Aalen-Johansen estimators. The risk-adjusted impact of pharmaceutical therapy for osteoporosis on the occurrence of further OAF during follow-up was analysed via multivariable Cox regressions with time-dependent covariates.

Results: At the time of PHF, 39% of patients had known osteoporosis, while only 12% were receiving pharmaceutical therapy using vitamin D/calcium or bisphosphonates. 23% of the patients had an OAF prior to PHF, with vertebral fractures and proximal femur fractures being the most common (12.6% and 10.7%, respectively). A similar picture appeared during the follow-up period: 5 years after PHF, 20.6% (20.1 – 21.1%) suffered at least one additional OAF, again with proximal femur and vertebral fractures being the most common with 10.5% (10.1 – 10.9%) and 10.1% (9.7 – 10.6%), respectively. 5 years after discharge of the index case, 33,4% of the living patients without pre-known osteoporosis were diagnosed, and only 19.8% received pharmaceutical therapy. After time-dependent risk adjustment, patients with untreated osteoporosis have an approximately 2-fold higher risk of suffering another OAF during the follow-up (HR 1.99; 95%CI 1.87 - 2.11; p<0.001). In patients with drug therapy compared to osteoporosis patients without therapy, the risk is only half as high (HR 0.55; 95%CI 0.51 - 0.58; p<0.001) and thus approximately comparable to the risk for patients without osteoporosis disease (HR 1.09; 95%CI 1.01 - 1.17; p=0.025).

Conclusion: Accurate diagnosis of osteoporosis and guideline-based implementation of an adequate therapy after PHF is essential to reduce secondary fractures. Without adequate therapy for osteoporosis, the risk of subsequent fracture was twofold higher. In view of the imminent demographic change, increased medical and political efforts are needed to ensure improved prophylaxis even in old age.