Improved clinical outcomes of outpatient enhanced recovery hip and knee replacements in comparison to standard inpatient procedures: A study of patients who experienced both

Orthop Traumatol Surg Res. 2022 Oct;108(6):103236. doi: 10.1016/j.otsr.2022.103236. Epub 2022 Feb 9.


Background: The benefits of combining enhanced recovery after surgery (ERAS) interventions with an outpatient program for total hip/knee arthroplasty (THA/TKA) are uncertain. This study's main objective was to evaluate adverse events with an ERAS-outpatient compared to standard-inpatient care and secondary objectives were to compare pain, functional recovery, PROMs and satisfaction.

Hypothesis: The ERAS-outpatient program would result in reduced adverse events compared to standard-inpatient care.

Methods: An ambidirectional single subject cohort study was conducted on 48 consecutive patients who experienced both a standard-inpatient and an ERAS-outpatient THA/TKA (contralaterally). Adverse event rate according to the Clavien-Dindo scale, the Comprehensive Complications Index (CCI) and the number of unplanned episodes of care were assessed. Postoperative pain on a numeric rating scale, opioid consumption in morphine milligram equivalents, functional recovery, patient reported outcome measures (PROMs) (WOMAC, KOOS, HOOS, Forgotten Joint Score and Patient Joint Perception) and patients' satisfaction were also evaluated.

Results: Following the ERAS-outpatient surgery, complication rates were reduced by more than 50% (2.1 vs. 4.4, p<0.001), CCI was significantly lower (12.3 vs. 19.1, p<0.001), and similar unplanned episodes of care were observed (p>0.999). In the first 8 postoperative hours, perceived pain was similar (p>0.805) while opioid consumption was significantly reduced (9.3 vs. 26.5, p<0.001). Patients walked, climbed stairs, showered, performed activities of daily living, practised sports, went back to work sooner (p<0.001), but PROMs were similar between groups at the last follow-up (p>0.188). Patients were more satisfied of the ERAS-outpatient pathway and recommended it significantly more (p<0.002).

Conclusion: Compared to the conventional inpatient care, the ERAS-outpatient program proved to be safer, enable faster functional recovery, and improve patients' satisfaction which highlight the importance of following ERAS principles when implementing an outpatient THA/TKA program.

Level of evidence: III; Ambidirectional Cohort study.

Keywords: Arthroplasty; Enhanced recovery after surgery; Fast-track; Hip; Knee; Outpatient; Replacement.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activities of Daily Living
  • Analgesics, Opioid
  • Arthroplasty, Replacement, Hip* / adverse effects
  • Arthroplasty, Replacement, Knee* / adverse effects
  • Cohort Studies
  • Humans
  • Inpatients
  • Morphine Derivatives
  • Outpatients


  • Analgesics, Opioid
  • Morphine Derivatives