Higher prevalence of vitamin D deficiency among arthroplasty patients presenting in winter.

Abstract

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. 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. 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. 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.