Abstract
BACKGROUND: As demand for total joint arthroplasty (TJA) continues to rise, there is ongoing interest in identifying modifiable risk factors associated with adverse surgical outcomes. Vitamin D deficiency has been identified as a target for pre-operative optimisation. This study aimed to define the prevalence of vitamin D deficiency among elective TJA patients. Secondary aims were to identify risk factors for vitamin D deficiency and to describe any association between deficiency and surgical outcomes. METHODS: This retrospective cohort study included all patients waitlisted for elective total hip or knee arthroplasty over a 2-year period, at a single centre in the South Island of New Zealand. Demographic data, pre-operative vitamin D levels and presence of regular vitamin D supplementation were collected. Surgical outcomes including length of stay, complications and reoperation rates were compared between groups. RESULTS: 328 patients were included. 92 (28%) were taking a monthly vitamin D supplement (cholecalciferol) prior to surgery. Of the remaining 236, 170 (72%) were deficient. Patients in the deficient group were younger (mean age 68 vs. 70 years, P = 0.02) and more likely to be male (OR 1.81, 95% CI 1.56-2.86, P < 0.01). Deficiency was significantly more likely in Winter (OR 3.61, 95% CI 1.21-10.8). While readmission rates were higher in the deficient group (7% vs. 1%, P = 0.04), the absolute number of events was small. CONCLUSION: There is a high prevalence of vitamin D deficiency among patients presenting for elective TJA. Regular vitamin D supplementation significantly reduces the likelihood of deficiency.