Is there an association between low serum 25-OH-D levels and the length of hospital stay in orthopaedic patients after arthroplasty?

BACKGROUND: The purpose of this observational study was to evaluate serum levels of 25-OH-D in patients scheduled to undergo elective hip or knee arthroplasty. We hypothesised that 25-OH-D level is an independent risk factor for length of stay in orthopaedic patients after elective hip or knee arthoplasty. MATERIALS AND METHODS: 25-OH-D levels were measured in 1083 patients admitted to an orthopaedic surgery department to undergo elective hip or knee arthroplasty. Comparisons were performed using Chi square or Student's t test, followed by univariate and multiple linear regression analysis examining the correlation between the length of stay in the orthopaedic department and 25-OH-D level while adjusting for possible confounders. RESULTS: Overall, 86 % of patients had insufficient serum levels of 25-OH-D, and over 60 % were vitamin D deficient. The mean length of stay was 13.2 ± 8.3 days. In patients with hypovitaminosis D, the length of stay was significantly longer compared to patients with normal serum 25-OH-D levels (15.6 ± 7.2 compared to 11.3 ± 7.9 days, P = 0.014). In univariate analyses, serum 25-OH-D level was inversely related to the length of stay in our orthopaedic department compared to patients with normal vitamin D levels (r = -0.16; P = 0.008). In multivariate analyses, the length of stay remained significantly associated with low 25-OH-D levels (P = 0.002), indicating that low vitamin D levels increase the length of stay. CONCLUSIONS: We found a high frequency of hypovitaminosis D among orthopaedic patients scheduled to undergo elective arthroplastic surgery. Low vitamin D levels showed a significant inverse association to the length of stay in our orthopaedic department. Patients with vitamin D levels in the target range were hospitalised 4.3 days less than patients with hypovitaminosis D. Level 3 of evidence according to "The Oxford 2011 levels of evidence".