Arthroplasty rates are increased among US patients with systemic lupus erythematosus: 1991-2005

To evaluate population-based systemic lupus erythematosus (SLE) arthroplasty rates and compare them with rates in patients with no inflammatory or autoimmune conditions.

Administrative hospital discharge databases from 10 American states were used to compare knee, hip, and shoulder arthroplasty rates from 1991 to 2005 in patients with SLE and in patients with no inflammatory or autoimmune conditions.

Arthroplasties were performed on patients with SLE (n = 4253) and patients with noninflammatory conditions (n = 2,762,660). Arthroplasty rates for patients with noninflammatory conditions almost doubled from 1991 to 2005 (124.5 cases/100,000 persons vs 247.5/100,000; p < 0.001). A similar trend was observed for SLE (0.17/100,000 vs 0.38/100,000; p < 0.001). The mean age at arthroplasty in patients with noninflammatory conditions decreased (71.5 ± 11.8 vs 69.0 ± 12.0; p < 0.001), whereas the mean age in patients with SLE increased (47.3 ± 17.0 vs 56.8 ± 16.0; p < 0.001). When stratified by age and sex, arthroplasty in cases of SLE increased in all groups except for women < 44 years old. In 1991, osteonecrosis accounted for 53% and osteoarthritis (OA) 23% of cases of SLE; by 2005 this relationship had reversed, with osteonecrosis accounting for 24% and OA 61% of cases of SLE.

From 1991 to 2005, arthroplasty rates increased in patients with SLE in similar proportions to overall joint replacement rates. The age of patients with SLE arthroplasty increased and fewer cases were due to osteonecrosis. These data suggest significant changes are occurring - patients with SLE are now living long enough to develop OA and are healthy enough to undergo elective surgery.