Does Vitamin D Deficiency Lead to Poorer Health Outcomes After (Total) Knee Arthroplasty? a Systematic Review and Meta-Analysis

Abstract Aims Vitamin D deficiency is a predictor of poorer musculoskeletal disease outcomes and affects approximately 1-in-4 people. Prior literature has assessed the effects of vitamin D deficiency in joint arthroplasties. This updated systematic review and meta-analysis aims to evaluate and collate evidence available on vitamin D supplementation in total knee arthroplasty (TKA). Methods A targeted terms search related to vitamin D and TKA outcomes was conducted (data inception until 01/09/2021). PubMed, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, American Academy of Orthopaedic Surgeons and British Orthopaedic Association databases were used. Analyses consisted of forest plots with I2 heterogeneity statistics, pooled effects with 95% confidence intervals (CI) and, p-values. A p < 0.05 was considered statistically significant. Results 10 studies fitted inclusion criteria for narrative description and 3 for meta-analysis. 6 studies showed improved outcomes in revision surgery risk, joint infection incidence and postoperative function. Additionally, there were poorer outcomes in postoperative stiffness, prosthesis explanation and postoperative vascular events. Meta-analysis of the length of hospital stay (LOS) demonstrated a significant decrease in LOS between vitamin D sufficiency versus deficiency (standard mean difference = -0.54, 95% CI [-0.69, -0.38], p<0.00001) favouring vitamin D sufficiency. Conclusion Vitamin D supplementation demonstrated a statistically significant benefit for TKA patients regarding LOS. Most studies found positive effects of vitamin D supplementation improving patients’ health, reducing hospital resource use, and decreasing the burden on surgeons. Further research with standardised assessment scores is required to definitively prove the vitamin D screening and supplementation benefits in TKA.