Big data analysis reveals significant increases in complications, costs, and hospital stay in revision total knee arthroplasty compared to primary TKA

INTRODUCTION: Despite significant advancements in total knee arthroplasty (TKA), some patients require revision surgery (R-TKA) due to complications such as infection, mechanical loosening, instability, periprosthetic fractures, and persistent pain. This study aimed to explore the specific causes leading to R-TKA, associated complications, including infection, mechanical failure, and wound issues, as well as costs, mortality rates, and hospital length of stay (LOS) using data from a large national database. METHODS: Data from the nationwide inpatient sample (NIS), the largest publicly available all-payer inpatient care database in the United States were analysed from 1 January 2016 to 31 December 2019. The study included 44, 649 R-TKA cases, corresponding to 223, 240 patients, with exclusions for nonelective admissions. Various statistical analyses were used to assess clinical outcomes, including in-hospital mortality, postoperative complications, LOS, and hospitalization costs. RESULTS: Among 2, 636, 880 TKA patients, 8. 4% underwent R-TKA. R-TKA patients had higher rates of chronic conditions, including mental disorders (36. 4%) and renal disease (9. 9%). Additionally, these patients often experienced instability, necessitating revision surgery. Infection (22. 3%) was the primary reason for R-TKA, followed by mechanical loosening (22. 9%) and instability. Compared to primary TKA patients, R-TKA patients exhibited higher in-hospital mortality (0. 085% vs. 0. 025%), longer LOS (3. 1 vs. 2. 28 days), and higher total charges (97, 815 vs. 62, 188). Postoperative complications, including blood transfusion (4. 6% vs. 1. 3%), acute kidney injury (4. 4% vs. 1. 8%), venous thromboembolism (0. 55% vs. 0. 29%), infection, and wound problems, were significantly higher in R-TKA patients. CONCLUSIONS: This study provides detailed insights into t LOS, costs, and complications associated with specific etiologies of revision TKA. Our findings emphasize the need for targeted preoperative optimization and patient education. This approach can help reduce the incidence and burden of R-TKA, improve patient care, optimize resource allocation, and potentially decrease the overall rates of complications in revision surgeries. LEVEL OF EVIDENCE: Level III.