Outcomes Following Total Hip Arthroplasty for Osteonecrosis of the Femoral Head in Patients on Hemodialysis.

ABSTRACT

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a potentially debilitating condition, often requiring total hip arthroplasty (THA). Patients on hemodialysis (HD) are at increased risk for complications after THA for osteoarthritis, however there is limited information on outcomes of THA for ONFH in patients on HD. With increasing prevalence of chronic kidney disease (CKD) requiring HD, studies are needed to characterize the risk of complications in these patients. Therefore, the purpose of this study was to evaluate HD as a potential risk factor for complication after THA in patients with ONFH on HD. METHODS: Patients on HD with ONFH who underwent THA with at least 2 years of follow-up were identified using a combination of ICD-9 and CPT codes in a national insurance database. A 101 matched control cohort of patients with ONFH not on HD was created for comparison. A logistic regression analysis was used to evaluate rates of death, hospital readmission, emergency room (ER) visit, infection, revision, and dislocation between cohorts. Differences in hospital charges, reimbursement, and length of stay between the two groups were also assessed. RESULTS: One thousand one hundred thirty-seven patients on HD who underwent THA for ONFH were compared to a matched control cohort of 11,182 non-HD patients who underwent THA for ONFH. Patients on HD experienced higher rates of death (HD 4.1%, non-HD 0.9%; odds ratio [OR] 3.35, p < 0.01), hospital readmission (HD 16.1%, non-HD 5.9%; OR 2.69, p < 0.01) and ER visit (HD 10.4%, non-HD 7.4% OR 1.5, p < 0.01). Hemodialysis was not associated with higher risk of infection, revision, or dislocation, but was associated with significantly higher charges (p < 0.01), reimbursement (p < 0.01), and hospital length of stay (p < 0.01). CONCLUSIONS: While patients on HD do not have increased risk of implant-related complications, they are at increased risk of developing medical complications following THA for ONFH and subsequently may require more resources. Orthopedic surgeons and nephrologists should be cognizant of the increased risk in this population to provide appropriate preoperative counseling and enhanced perioperative medical management. LEVEL OF EVIDENCE Therapeutic Level III.