Are Patients Being Appropriately Selected for Same-Day Discharge Total Knee Arthroplasty?

Background: Decreased cost associated with same-day discharge (SDD) total knee arthroplasty (TKA) has led to an increased interest in this topic. The purpose of this study is to investigate whether there is a population of TKA patients in which SDD has similar rates of 30-day complications compared to patients discharged on postoperative day 1 or 2. Methods: Using the American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2018, 6,327 TKA patients who had a SDD (length of stay [LOS] = 0) were matched to TKA patients who had an LOS of 1 or 2 days. All SDD patients were successfully matched 1:1 using the morbidity probability variable (a composite variable of demographics, comorbidities, and laboratory values). Patients were divided into quartiles based on their morbidity probability. Bivariate logistic re-gressions were then used to compare any complication and major complication rates in the SDD quartiles to the corresponding quartiles with an LOS of 1 or 2 days. Results: When comparing the 1st quartiles (healthiest), there was no difference between the cohorts in any complication (odds ratio [OR] = 0.960, 95% CI 0.552-1.670, P = .866) and major complications (OR = 0.999, 95% CI = 0.448-2.231, P = .999). The same was observed in quartile 2 (any complications: OR = 1.161, 95% CI = 0.720-1.874, P = .540). Comparing the third quartiles, there was an increase in all complications with SDD (OR = 1.784, 95% CI = 1.125-2.829, P = .014), but no difference in major com-plications (OR = 1.635, 95% CI = 0.874-3.061, P = .124). Comparing the fourth quartiles (least healthy), there was an increase in all complications (OR = 1.384, 95% CI = 1.013-1.892, P = .042) and major complications (OR = 1.711, 95% CI = 1.048-2.793, P = .032) with SDD. Conclusion: The unhealthiest 50% of patients in this study who underwent SDD TKA were at an increased risk of having any complication, calling into question the current state of patient selection for SDD TKA. Level of Evidence: III. (c) 2022 Elsevier Inc. All rights reserved.