Kong Y, Han M, Lee M, et al. - In this study, a correlation between calcium and vitamin D use and the revision rate after primary total knee arthroplasty were investigated. Researchers performed a nationwide population-based cohort study applying the Korean National Health Insurance database. Between 2009 and 2018, they enrolled patients diagnosed with knee osteoarthritis and had undergone primary total knee arthroplasty. They calculated the risk for arthroplasty revision applying a Cox proportional hazards model with time-dependent covariates. Survival of knee arthroplasty was evaluated using long-rank test. After total knee arthroplasty, combination use of calcium and vitamin D with a dose of 800 IU or greater for more than 1 year was correlated with the greatest reduction in the risks for revision surgery.