Hemoglobin A1C as a marker for surgical risk in diabetic patients undergoing total joint arthroplasty.

Diabetes is a risk factor for complications following total joint arthroplasty (TJA). This retrospective cohort study of 6088 diabetic patients from the Veterans Health Administration (VHA) undergoing TJA sought to determine if hemoglobin A1c, an accessible and objective lab value, has utility as a predictor of risk of complications in TJA after controlling for demographic, surgical, and medical center effects, and to evaluate the benefits and risks of alternative thresholds. Analysis of the functional relationship between hemoglobin A1c and complications revealed that the risk linearly increases through, rather than surging at, the threshold of 7%. Before delaying surgery to achieve better diabetic control, surgeons and patients should weigh the estimated risks of TJA against the potential benefits.