Abstract
INTRODUCTION: Systemic lupus erythematosus (SLE) often causes joint complications requiring total hip or knee arthroplasty (THA/TKA). SLE patients face higher postoperative complications, increasing 30-day readmission risk and hospital costs under Centers for Medicare and Medicaid Services Hospital Readmissions Reduction Program. This study evaluates readmission rates, causes, and risk factors in SLE patients post-THA/TKA. METHODS: We retrospectively examined the 2017-2020 Nationwide Readmission Database to identify yearly national readmission rates in SLE patients after THA/TKA, the reasons for 30-day readmission, and variables associated with the readmissions. Patients were Identified using ICD codes. We performed multivariable logistic regression models to identify factors associated with risk of readmission. RESULTS: The final cohort had 41,095 SLE patients underwent THA (19,631) or TKA (21,464). Medicare patients comprised the majority of the THA (70.9 %) and TKA (74.8 %) cohort. Readmission within 30 days occurred among 6.1 % of THA patients and 4.8 % of TKA patients. From 2017 to 2020, THA readmission rates increased from 6.5 % to 9.2 %. TKA readmissions stayed stable through the study period at 5.5 %. Sepsis (14.6 %), nonseptic infections (14.8 %), cardiovascular (11.2 %), and pulmonary complications (8.4 %) were leading causes of readmission for THA patients, while sepsis (10.4 %), joint/prosthetic infections (13.5 %), and cardiovascular complications (8.2 %) were the most common causes for TKA patients. Younger age, Charleson Comorbidity Index (CCI) score of ≥3, female sex, and length of stay (LOS) ≥ 3 days were significantly associated with higher odds of readmission for THA patients. Older age, CCI scores ≥3, and LOS ≥5 days were significantly associated with higher odds of readmission for TKA patients. DISCUSSION: SLE patients undergoing THA/TKA have high readmission rates, mainly due to infections and organ complications. Younger age and higher CCI increase risk, suggesting that preoperative planning and postoperative monitoring, especially for younger Medicare patients, may help reduce readmissions and improve outcomes. LEVEL OF EVIDENCE: III.