Background/Purpose: There is little data regarding patterns of arthroplasty use in patients with Systemic Lupus Erythematosus (SLE). This study evaluates trends in total joint replacement (TJR) for SLE from 1991-2005. Comparisons are made to patients with non-inflammatory conditions.

Methods:  Administrative hospital discharge databases from 10 states (AZ, CA, CO, FL, IA, MA, NJ, NY, WA, WI) and census data annual population estimates were used to compute annual rates per 100,000 population of knee arthroplasty, total and partial hip arthroplasty, and total and partial shoulder arthroplasty for the years 1991 to 2005 in patients with SLE and those with no inflammatory or autoimmune diseases.  ICD-9-CM codes were used to identify specific diseases.

Results:  During the 15 year study period, 4253 TJR were performed for patients with SLE and 2,762,660 TJR for patients with no inflammatory or autoimmune disease. SLE patients were younger (54 +/- 16 years vs 70.5 +/- 12.1 years) and much more likely to be female (90.2% vs 63.5%). Hip arthroplasty was the most frequent procedure in SLE patients (50.1% vs. 31.1%), whereas knee arthroplasty was most common in the non-inflammatory group (33.7% for SLE patients vs. 47.4%); TJR rates for patients with non-inflammatory conditions almost doubled from 1991 to 2005 (124.5/100,000 in 1991 vs. 247.5/100,000 in 2005, p-value <0.001). A similar trend was observed for SLE; (0.17/100,000 vs. 0.38/100,000, p<0.001). In particular, the proportion of total knee replacements among SLE patients increased from 15% in 1991 to 45% in 2005. The mean age of patients undergoing TJR with non- inflammatory conditions decreased (71.5±11.8 yrs in 1991, 69.0±12.0 yrs in 2005, p-value <0.001).  In contrast, the mean age of SLE TJR increased (47.3+/-17.0 vs 56.8+/-16.0, p-value<0.001). When stratified by age and gender, TJRs in SLE patients increased in all groups except for women with SLE <44 years of age. In this group rates decreased from 0.073/100000 to 0.067/100000 ( p-value=0.009).

Conclusion:  To our knowledge this is the first evaluation of TJR rates in SLE patients. From 1991-2005 arthroplasty rates increased in patients with SLE in similar proportions to overall TJR rates. This was surprising, as we had expected a decrease in TJR mirroring improved SLE mortality rates and decreases in end stage renal disease. However, the decrease in TJR among women < 44 years suggests treatment may be preventing early damage from severe active disease. In addition, while the mean age of non-inflammatory TJR fell, the age at time of SLE TJR increased. We speculate that improvements in SLE therapy may allow patients to live long enough to suffer both the osteonecrotic effects of steroids, possibly develop degenerative changes and also be healthy enough to receive an elective TJR. Increases in knee arthroplasty among SLE patients may also reflect lower SLE morbidity, and mortality, with SLE patients living long enough to develop age/obesity related knee OA. Further study is needed to see if these trends continue with ongoing improvements in SLE clinical care.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/arthoplasty-rates-increased-among-us-patients-with-systemic-lupus-erythematosus-1991-2005/