Outpatient Versus Hospital-Based Total Knee Arthroplasty: A Survey-Based Comparison of Complications, Infection, and Patient Satisfaction in a Contemporary U.S. Cohort.

Introduction The use of outpatient pathways for total knee arthroplasty (TKA) has expanded with advances in perioperative optimization and risk stratification; however, concerns remain regarding safety and patient outcomes. This study aimed to compare postoperative complications, infection rates, and patient satisfaction between an outpatient surgery center and hospital-based TKA, while assessing the relative contribution of patient-level factors to outcomes. Methodology A cross-sectional survey of 384 adults in the United States who had undergone primary TKA was conducted. Individuals with additional joint arthroplasties were excluded to isolate the effect of the surgical setting, resulting in 305 hospital TKAs and 79 outpatient TKAs. The primary exposure was a surgical setting. Primary outcomes included any self-reported postoperative complication, infection, and willingness to undergo TKA again. Outcomes were compared using chi-square and t-tests. Multivariable logistic regression was performed, adjusting for age, sex, body mass index (BMI), diabetes, surgical technique, and physical therapy adherence. Results Outpatient TKA patients were younger (47.6 vs. 55.4 years, P < 0.00001) and more frequently male (55.7% vs. 40.3%, P = 0.0199). These differences reflect real-world patient selection patterns for outpatient arthroplasty and indicate baseline imbalance between cohorts. Diabetes prevalence did not differ significantly between groups (17.4% vs. 13.9%, P = 0.57). Rates of complications (34.2% vs. 31.8%, P = 0.79), infection (5.1% vs. 8.5%, P = 0.43), and willingness to undergo TKA again (82.3% vs. 77.0%, P = 0.40) were similar between outpatient and hospital settings. Among older patients (≥56 years), outpatient TKA was associated with a higher proportion of patients willing to undergo the procedure again (91.3% vs. 75.4%). In adjusted analyses, surgical setting was not associated with complications (odds ratio (OR) 0.83, 95% confidence interval (CI) 0.47-1.47, P = 0.52), infection (OR 0.41, 95% CI 0.13-1.27, P = 0.12), or satisfaction (OR 1.21, 95% CI 0.61-2.43, P = 0.58). Higher BMI (OR 1.07, 95% CI 1.03-1.11, P = 0.0012) and male sex (OR 0.26 for female vs. male, 95% CI 0.11-0.61, P = 0.0021) were associated with increased infection risk. Robotic-assisted TKA (OR 3.29, 95% CI 1.43-7.57, P = 0.0052) and male sex (OR 0.47 for female vs. male, 95% CI 0.27-0.82, P = 0.0078) were associated with higher satisfaction. Diabetes was associated with increased complications (OR 1.95, 95% CI 1.06-3.57, P = 0.030) and lower satisfaction (OR 0.47, 95% CI 0.24-0.92, P = 0.027), but not infection. Conclusions Outpatient TKA was associated with similar observed rates of complications, infection, and patient satisfaction compared with hospital-based TKA in this cohort; however, these findings should be interpreted with caution, given baseline differences between groups and the potential for residual confounding. Patient-level factors, including BMI, sex, diabetes, and use of robotic assistance, appear to have a greater impact on outcomes than surgical setting. These findings support outpatient TKA as a safe and effective approach and emphasize the importance of individualized risk stratification and perioperative optimization.