Lupus is associated with poorer outcomes after primary total hip arthroplasty.

Objective: The aim of this study was to assess whether lupus is associated with poorer outcomes after primary total hip arthroplasty (THA).

Methods: We used the 1998-2014 US National Inpatient Sample data. Multivariable-adjusted separate logistic regression models assessed the association of lupus with post-operative complications (implant infection, transfusion, THA revision and mortality) and health care utilization outcomes (total hospital charges, discharge to an inpatient facility and length of hospital stay >3 days) post-THA, adjusting for demographics, underlying diagnosis, comorbidity, insurance payer and hospital characteristics, using odds ratios (OR) and 95% confidence intervals (CI).

Results: Among 4,116,485 primary THA hospitalizations, 22,557 (0.5%) were in patients with lupus. Patients with lupus were younger and more likely to be female, African-American or Hispanic, living in the South, or to have Medicaid insurance, and had higher comorbidity or lower income. In multivariable-adjusted analyses, the presence of lupus was associated with significantly higher risk of implant infection, transfusion, discharge to an inpatient facility and higher hospital charges above the median, with respective ORs of 1.95 (95% CI, 1.28, 2.97), 1.34 (95% CI, 1.25, 1.43), 1.21 (95% CI, 1.01, 1.44) and 1.38 (95% CI, 1.30, 1.47). Lupus was not significantly associated with the risk of revision, mortality or hospital stay >3 days; the ORs were 1.10 (95% CI, 0.68, 1.78), 0.95 (95% CI, 0.61, 1.47) and 1.06 (95% CI, 0.99, 1.13), respectively.

Conclusions: Lupus was associated with a higher risk of implant infection, transfusion, discharge to an inpatient facility and higher hospital charges post-primary THA. Insight into modifiable factors associated with these outcomes may improve outcomes in patients with lupus undergoing THA.