Inpatient Versus Outpatient Arthroplasty: A Single-Surgeon, Matched Cohort Analysis of 90-Day Complications

J Arthroplasty. 2019 Feb;34(2):221-227. doi: 10.1016/j.arth.2018.10.015. Epub 2018 Oct 17.

Abstract

Background: Although some prior work supports the safety of same-day arthroplasty performed in a hospital, concerns remain when these procedures are performed in a free-standing ambulatory surgery center. The purpose of this study is to compare 90-day complication rates between matched cohorts that underwent inpatient vs outpatient arthroplasty at an ambulatory surgery center.

Methods: A single-surgeon cohort of 243 consecutive patients who underwent outpatient arthroplasty was matched with 243 inpatients who had the same procedure. One-to-one nearest-neighbor matching with respect to gender, age, American Society of Anesthesiologists Score, and body mass index was utilized. The 486 primary arthroplasties included 178 unicondylar knees (36.6%), 146 total hips (30.0%), 92 total knees (18.9%), and 70 hip resurfacings (14.5%). Ninety-day outcomes including reoperation, readmission, unplanned clinic or emergency department visits, and major and minor complications were compared using a 2-sample proportions test.

Results: The 2 cohorts were similar in distribution of demographic variables, demonstrating successful matching. The inpatient and outpatient cohorts both had readmission rates of 2.1% (P = 1.0). With the number of subjects studied, there were no statistically significant differences in rates of major complications (2.1% vs 2.5%, P = 1.0), minor complications (7.0% vs 7.8%, P = .86), reoperations (0.4% vs 2.1%, P = .22), emergency department visits (1.6% vs 2.5%, P = .52), or unplanned clinic visits (3.3% vs 5.8%, P = .19).

Conclusion: This study suggests that arthroplasty procedures can be performed safely in an ambulatory surgery center among appropriately selected patients without an increased risk of complications.

Keywords: complications; outpatient hip arthroplasty; outpatient hip resurfacing; outpatient knee arthroplasty; outpatient unicondylar knee replacement.

Publication types

  • Comparative Study

MeSH terms

  • Ambulatory Care Facilities
  • Arthroplasty, Replacement, Hip / adverse effects*
  • Arthroplasty, Replacement, Hip / statistics & numerical data
  • Arthroplasty, Replacement, Knee / adverse effects*
  • Arthroplasty, Replacement, Knee / statistics & numerical data
  • Chicago / epidemiology
  • Cohort Studies
  • Emergency Service, Hospital
  • Female
  • Hospitals
  • Humans
  • Inpatients / statistics & numerical data*
  • Middle Aged
  • Outpatients / statistics & numerical data*
  • Postoperative Complications / epidemiology*
  • Postoperative Complications / etiology
  • Reoperation / adverse effects
  • Surgeons