Inpatient Hospital Costs, Emergency Department Visits, and Readmissions for Revision Hip and Knee Arthroplasty.

BACKGROUND: Revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) tremendously burden hospital resources. This study evaluated factors influencing perioperative costs, including emergency department (ED) visits, readmissions, and total costs-of-care within 90 days following revision surgery.

METHODS: A retrospective analysis of 772 revision TKAs and THAs performed on 630 subjects at a single center between January 2007 and December 2019 was conducted. Cost data was available from January 2015 to December 2019 for 277 patients. Factors examined included comorbidities, demographic information, pre-operative Anesthesia Society of Anesthesiologists score, implant selection, and operative indication using mixed-effects linear regression models.

RESULTS: Among 772 revisions (425 THA and 347 TKA), 213 patients required an ED visit, and 90 required hospital readmission within 90 days. There were 22.6% of patients who underwent a second procedure after their initial revision. Liver disease was a significant predictor of ED readmission for THA patients (multivariable OR [odds ratio]: 3.473, P = 0.001), while aseptic loosening, osteolysis, or instability significantly reduced the odds of readmission for TKA patients (OR: 0.368, P = 0.014). In terms of ED visits, liver disease increased the odds for THA patients (OR: 1.845, P = 0.100), and aseptic loosening, osteolysis, or instability decreased the odds for TKA patients (OR: 0.223, P < 0.001). Increased age was associated with increased costs in both THA and TKA patients, with significant cost factors including congestive heart failure for TKA patients (OR: $7,308.17, P = 0.004) and kidney disease for THA patients. Revision surgeries took longer than primary ones, with TKA averaging 3.0 hours (1.6 times longer) and THA 2.8 hours (1.5 times longer).

CONCLUSION: Liver disease increases ED readmission risk in revision THA, while aseptic loosening, osteolysis, or instability decreases it in revision TKA. Increased age and CHF are associated with increased costs. These findings inform postoperative care and resource allocation in revision arthroplasty.