DOS 2018

220 · DOS Abstracts Vitamin D insufficiency among patients undergoing hip or knee arthroplasty. Preliminary results from a prospective cohort study. Kristoffer Lindvig, Rehne Lessmann Hansen Orthopaedic Surgery Department, Regional Hospital Horsens Background: Recent studies find that vitamin D (vit. D) insufficiency (<50nmol/l) is associated with adverse events after joint replacement sur- gery such as postoperative infections, joint stiffness and longer hospital stay. Experimental rat studies find that low vit. D concentrations markedly impairs the implant osseointegration. In a general Danish population the prevalence of vit. D insufficiency is reported to be 52.2%. Correction of vit. D insufficiency is cheap; however, vit. D concentration is rarely measured before joint replace- ment surgery. Purpose / Aim of Study: The purpose was to estimate the prevalence of vit. D insufficiency in patients undergoing hip or knee arthroplasty. Materials and Methods: Patients scheduled for uncemented total hip, hybrid total knee or unicompartment knee arthroplasty were consecutively enrolled. Bloodsamples (calcium, parathyroid hormone, vit. D2 and D3) and question- naires were collected preoperatively and after six months. Follow- up is com- pleted September 2018. Vit. D insufficiency was corrected with oral supple- ments of calcium (800mg) and vit. D (38µg). Findings / Results: We included 185 patients with a mean age of 66.3 years (range 36 to 86). Preoperatively 22% (n=40) had vit. D insufficiency and after six months 12% (n=8) had vit. D insufficiency (p= 0.58). Two patients were diagnosed with primary hyperparathyroidism and six had secondary hyperpara- thyroidism. Patients preoperatively diagnosed with vit. D insufficiency had a significant increase from 35nmol/L (SD= 8.17) to 89.5nmol/L (SD=24.4) (p= 0.001) in vit. D concentration at six months follow-up. Conclusions: Vit. D insufficiency is present in more than 20% of the patients scheduled for hip or knee arthroplasty and correction should be considered be- fore undertaking joint replacement surgery. 161.