Cohen JS, et al. - Experts evaluated the impact of less severe, but clinically significant, renal impairment following revision total knee arthroplasty. They conducted a retrospective cohort study using the American College of Surgeons National Quality Improvement Program Database. Greater risk for many postoperative complications is seen in the patients with decreased eGFRs, but this increased risk is generally associated with the greater number of comorbidities in this patient population. When controlling for these comorbidities, an independent risk factor for extended length of stay as well as postoperative renal injury and renal failure is poor renal function, and patients may benefit from perioperative measures to limit this excess renal risk.