Inpatient mortality and morbidity for dialysis-dependent patients undergoing primary total hip or knee arthroplasty

Background: Dialysis-dependent patients can develop osteoarthritis or osteonecrosis, warranting hip or knee arthroplasty. Their comorbidities predispose them to complications. Our goal was to determine inpatient outcomes of dialysisdependent patients after primary elective total hip or knee arthroplasty. Methods: In the National Inpatient Sample, we identified 2934 dialysis-dependent patients who had undergone total hip or knee arthroplasty from 2000 through 2009 and compared them with 6,186,475 patients who had undergone the same procedures and were not dialysis-dependent. We described demographic characteristics, comorbidities, and outcomes and assessed associations of dialysis status with inpatient mortality and complications. Results: In the hip arthroplasty group, dialysis-dependent patients were younger (63.2 compared with 65.2 years; p = 0.0476) and more commonly diagnosed with osteonecrosis (34.29% compared with 10.94%; p < 0.0001) than nondialysis- dependent patients. Dialysis-dependent patients had higher inpatient mortality rates (1.88% compared with 0.13%; p < 0.0001) and greater overall complication rates (9.98% compared with 4.97%; p = 0.0001). Dialysis was an independent risk factor for mortality (odds ratio, 6.66; 95% confidence interval [95% CI], 2.66 to 16.66) and complications (odds ratio, 1.53; 95% CI, 1.01 to 2.33). In the knee arthroplasty group, dialysis-dependent patients were similar in age (66.7 compared with 66.8 years; p = 0.8085) and were more commonly diagnosed with osteonecrosis (3.32% compared with 0.74%; p < 0.0001) than non-dialysis-dependent patients. Dialysis-dependent patients had higher inpatient mortality rates (0.92% compared with 0.10%; p < 0.0001) and greater overall complication rates (12.48% compared with 5.00%; p < 0.0001). Dialysis status was an independent risk factor for mortality (odds ratio, 3.31; 95% CI, 1.04 to 10.54) and complications (odds ratio, 1.86; 95% CI, 1.34 to 2.60). Conclusions: Total hip and knee arthroplasty in dialysis-dependent patients presents high risk, with inpatient mortality rates ten to twenty times greater and overall complication rates two times greater than in non-dialysis-dependent patients. Arthroplasty should be approached with caution and preferably should be delayed until after renal transplantation. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.