Objective To examine whether racial disparities in usage and outcomes of total knee and total hip arthroplasty (TKA and THA) have declined over time.

Methods We used data from the US Medicare Program (MedPAR data) for years 1991–2008 to identify four separate cohorts of patients (primary TKA, revision TKA, primary THA, revision THA). For each cohort, we calculated standardised arthroplasty usage rates for Caucasian and African–American Medicare beneficiaries for each calendar year, and examined changes in disparities over time. We examined unadjusted and adjusted outcomes (30-day readmission rate, discharge disposition etc.) for Caucasians and African–Americans, and whether disparities decreased over time.

Results In 1991, the use of primary TKA was 36% lower for African–Americans compared with Caucasians (20.6 per 10 000 for African–Americans; 32.1 per 10 000 for Caucasians; p<0.0001); in 2008, usage of primary TKA was 40% lower for African–Americans (41.5 per 10 000 for African–Americans; 68.8 per 10 000 for Caucasians; p<0.0001) with similar findings for the other cohorts. Black–White disparities in 30-day hospital readmission increased significantly from 1991–2008 among three patient cohorts. For example in 1991 30-day readmission rates for African–Americans receiving primary TKA were 6% higher than for Caucasians; by 2008 readmission rates for African–Americans were 24% higher (p<0.05 for change in disparity). Similarly, black–white disparities in the proportion of patients discharged to home after surgery increased across the study period for all cohorts (p<0.05).

Conclusions In an 18-year analysis of US Medicare data, we found little evidence of declines in racial disparities for joint arthroplasty usage or outcomes.