Abstract
BACKGROUND: The number of patients with systemic lupus erythematosus (herein, lupus) undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) is increasing. There is disagreement about the effect of lupus on perioperative complication rates. We hypothesized that lupus would be associated with higher complication rates in patients who undergo elective primary THA or TKA. METHODS: Records of more than 6.2 million patients from the National Inpatient Sample who underwent elective primary THA or TKA from 2000 to 2009 were reviewed. Patients with lupus (n = 38,644) were compared with those without lupus (n = 6,173,826). Major complications were death, pulmonary embolism, myocardial infarction, stroke, pneumonia, and acute renal failure. Minor complications were wound infection, seroma, deep vein thrombosis, hip dislocation, wound dehiscence, and hematoma. Patient age, sex, duration of hospital stay, and number of Elixhauser comorbidities were assessed for both groups. Multivariate logistic regression models using comorbidities, age, and sex as covariates were used to assess the association of lupus with major and minor perioperative complications. The alpha level was set to 0.001. RESULTS: Among patients who underwent THA, those with lupus were younger (mean age, 56 vs. 65 years), were more likely to be women (87% vs. 56%), had longer hospital stays (mean, 4.0 vs. 3.8 days), and had more comorbidities (mean, 2.5 vs. 1.4) than those without lupus (all p < 0.001). In patients with THA, lupus was independently associated with major complications (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1 to 1.7) and minor complications (OR, 1.2; 95% CI, 1.0 to 1.5). Similarly, among patients who underwent TKA, those with lupus were younger (mean, 62 vs. 67 years), were more likely to be women (93% vs. 64%), had longer hospital stays (mean, 3.8 vs. 3.7 days), and had more comorbidities (mean, 2.8 vs. 1.7) than those without lupus (all p < 0.001). However, in TKA patients, lupus was not associated with greater odds of major complications (OR, 1.2; 95% CI, 0.9 to 1.4) or minor complications (OR, 1.1; 95% CI, 0.9 to 1.3). CONCLUSIONS: Lupus is an independent risk factor for major and minor perioperative complications in elective primary THA but not TKA.