Evaluation of Risk Factors For 90-Day Unplanned Readmissions After Total Knee Arthroplasty

Purpose: To determine the major predictive factors for 90-day unplanned readmission (UR) in patients whounderwent unilateral, simultaneous bilateral or staged bilateral total knee arthroplasty (TKA).Methods: The data of patients who underwent elective TKA between 2011 and 2016 were evaluated from ourmedical records. Patients were divided into three groups according to the type of TKA procedure as unilateral,staged bilateral and simultaneous bilateral TKA groups. Age, gender, body mass index (BMI), systemic comorbiddiseases, and American Society of Anesthesiologists (ASA) scores, anesthesia technique, total operation time,presence of tranexamic acid administration, total number of blood unit transfused ,and total length of hospitalstay were investigated through medical records. The data of patients with 90-day UR and no 90-day UR werecompared by student t-test, Pearson Chi-Square test, and Fisher’s exact test. Finally, multivariate analysis wasperformed to determine the major predictive factors of 90-day UR.Results: Total operative time, total amount of blood unit transfused, and total length of hospital stay weresignificantly higher in patients who had 90-day UR. No significant difference was observed among TKA groupsin 90-day UR rates. According to multivariate logistic regression analysis, increased total length of hospital staywas determined as the only major predictor of 90-day UR.Conclusion: According to our results, no significant difference was observed among unilateral, simultaneousbilateral and staged bilateral TKA groups in 90-day UR. The increased length of hospital stay was found as themajor predictor of 90-day UR.