Outcome of total hip and total knee arthroplasty and vitamin D homeostasis

Background Low levels of vitamin D are common in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), but it is still unclear whether the outcome of such surgery is related to vitamin D levels. Sources of data Publicly available electronic databases were systematically reviewed to update knowledge about the role of vitamin D in THA and TKA patients, and to appraise the correlation between vitamin D levels before surgery and post-surgical outcomes. Eight studies were included in our review: six employed prospective observational designs, two reported retrospective database interrogations. Six prospective observational studies and two retrospective database interrogations matched inclusion and exclusion criteria. Areas of agreement Patients undergoing THA and TKA have a high prevalence of hypovitaminosis D. Five of eight studies (62.5%) report a statistically significant association between low vitamin D status and worse outcomes after THA and TKA. Areas of controversy Different explanations have been proposed for vitamin D insufficiency, but some authors have questioned the correctness of the methods used to measure the vitamin D levels. Growing points A trial focusing on the role of vitamin D supplementation on safety and outcomes of patients undergoing THA and TKA with low vitamin D status is ongoing. Areas timely for developing research Further studies should explore the possible causal relationship between vitamin D status and outcomes of THA and TKA and verify the laboratory methods to analyse it.