Diabetes mellitus and selected bone-degrading drugs and their effect on reoperation-rate and mortality following internal fixation of femoral neck fractures

Abstract

Introduction: The purpose of this study was to evaluate whether diabetes mellitus and pre-trauma use of selected bone-degrading drugs affect the risk of reoperation and mortality following internal fixation of femoral neck fractures. The drugs under evaluation were non-steroid anti-inflammatory drugs (NSAIDs), proton pump inhibitors (PPIs), corticosteroids and other immune-suppressants. Materials and methods: This is a single-center retrospective cohort study focusing on skeletally mature patients who had undergone screw fixation for undisplaced femoral neck fractures in the period 2005-2013. All data had been prospectively documented. In this study, data about each patient’s medication use and history of diabetes mellitus were retrieved from electronic medical records and this information was added to an already established database where reoperations and mortality were registered. Results: 403 patients were included in the study. Of these, 10.9 % had a diagnosis of diabetes mellitus. Five patient records had incomplete information regarding medication, leaving 398 for relevant analyses. Of these 32.9 % used NSAIDs, 12.6 % used PPIs and 5% used corticosteroids. Six patients used other immune-suppressants. Neither diabetes mellitus nor any of the selected drugs had any significant effect on reoperation rate or one-year mortality. The expected median (95 % CI) survival following fracture was 15 months (0.0 to 37.9) and 35 months (28.2 to 41.8) for men with and without diabetes mellitus respectively. For women the expected median (95 % CI) survival was 38 months (16.8 to 59.2) and 67 months (56.8 to 77.2) for patients with and without diabetes mellitus respectively. The effect of diabetes mellitus adjusted for gender on expected survival was statistically significant (p = 0.04). Conclusions: Patients with diabetes mellitus had a significantly reduced expected median survival time compared to patients without diabetes. Diabetes mellitus did not appear to affect the reoperation rate. This also applied to the use of NSAIDs and PPIs. Not enough patients had been using corticosteroids or other immune-suppressants to legitimate any conclusion.