Starr J, et al. - Researchers retrospectively analyzed medical records of Veterans Affairs patients who underwent total knee arthroplasty (TKA) and created a risk calculator including opioid use or other risk factors for predicting total knee revision (TKR). The risk calculator was generated with a mean absolute error of 0.1% at 1 year and 3.6% at 5 years. They recognized that preoperative chronic opioid use is a predictor of TKR. Other model variables were age, female sex, body mass index, diabetes, chronic kidney disease, and nonchronic opioid use.