Total hip arthroplasty in chronic dialysis patients in the United States

BACKGROUND: The national incidence of and factors associated with total hip arthroplasty (THA) in chronic dialysis patients has never been reported. METHODS: We therefore performed an historical cohort study of 375,857 chronic dialysis patients listed in the 2000 United States Renal Data System between 1 April 1995 and 31 December 1999 and followed-up until 14 May 2000. Primary outcomes were associations with hospitalizations for a primary discharge code of THA (ICD9 procedure code 81.51x) after initiation of dialysis. RESULTS: Dialysis patients had a cumulative incidence of THA of 35 episodes/10,000 person-years, compared to 5.3/10,000 in the general population. The leading indication for THA was osteoarthritis of the hip and pelvis (58% of cases). However, the strongest risk factor for THA in dialysis patients was end-stage renal disease (ESRD) due to systemic lupus erythematosus (SLE, adjusted rate ratio (ARR), 6.80, 95% CI 4.62-10.03, in whom avascular necrosis of the hip was the most common indication, 68.4%). The database did not include information on use of corticosteroids. Diabetic recipients were significantly less likely to receive THA, as were males, and African Americans. Mortality after THA was 0.25% at thirty days and 30% at three years, not significantly different from the expected mortality of dialysis, adjusted for comorbidity. CONCLUSIONS: The most common indication for THA in dialysis patients is osteoarthritis of the hip, similar to the general population. Patients with SLE are more likely to receive THA which is well tolerated and not associated with increased mortality in this population, perhaps reflecting selection bias due to appropriate screening for this elective procedure.