Analysis of Factors Influencing Early Discharge in Patients Undergoing Knee Replacement Surgery Under the ERAS Protocol: A Single-Center Retrospective Cohort Study

Abstract

To investigate independent factors influencing early discharge (hospital stay ≤3 days postoperatively) among patients undergoing primary unilateral total knee arthroplasty (TKA) under the Enhanced Recovery After Surgery (ERAS) pathway, a retrospective cohort study design was employed in which a total of 316 patients who underwent ERAS pathway TKA in the Department of Orthopedics, Deyang People's Hospital, a Grade A Class 3 hospital (the top tier hospital in mainland China) from January 1, 2024, to December 31, 2025, were consecutively enrolled. In this study, patients were divided into an early discharge group (n=142) and a conventional discharge group (n=174) based on whether patients’ postoperative hospital stay was ≤3 days. Patient demographics, preoperative comorbidities and laboratory values, intraoperative data, and postoperative recovery indicators were all collected. Univariate analysis compared group differences, and statistically significant variables were included in a multivariate logistic regression model to identify independent factors influencing early discharge. Results showed: multivariate logistic regression analysis revealed that age <70 years (OR=2.41, 95% CI: 1.42-4.10), preoperative hemoglobin ≥130 g/L (OR=1.98, 95% CI: 1.18–3.33), intraoperative blood loss <100 ml (OR=2.85, 95% CI: 1.65–4.91), and those achieved ambulation within 24 hours postoperatively (OR=3.72, 95% CI: 2.14–6.48), and visual analog scale (VAS) score <4 on postoperative day 1 (OR=2.26, 95% CI: 1.31–3.89) were independent factors promoting early discharge. In conclusion: Under the ERAS pathway, early discharge in TKA patients is influenced by multiple factors. Optimizing preoperative patient status, refining surgical techniques to minimize trauma, and enhancing postoperative pain management and early rehabilitation are key to achieving safe early discharge. Identifying these factors assists clinical care teams in conducting precise preoperative assessments and perioperative management.