# Non-selective enhanced recovery pathway in primary hip and knee arthroplasty: a propensity score matched analysis on safety and efficacy

## TL;DR

A universal ERAS program for hip and knee replacement surgeries safely reduced hospital stays and costs without increasing complications.

## Contribution

Demonstrates the safety and efficacy of a non-selective ERAS pathway in primary hip and knee arthroplasty across diverse patient groups.

## Key findings

- ERAS reduced median length of stay by two days compared to standard care.
- ERAS showed lower rates of readmission, infection, and mortality, though not statistically significant.
- Cost per patient was reduced by an estimated £718.60 with ERAS.

## Abstract

Enhanced Recovery After Surgery (ERAS) was introduced in hip and knee arthroplasty to expedite recovery, shorten inpatient stay, and reduce costs. This study aims to investigate the safety and efficacy of implementing a universal standardized non-selective ERAS service for all patients admitted for primary hip and knee arthroplasty in a single high-volume tertiary orthopaedic centre.

All patients who underwent primary hip or knee arthroplasty under ERAS from April 2023 to March 2024 were compared with a matched cohort between January 2018 and December 2019. Patients were matched at a 2:1 ratio based on procedure, age, sex, ASA grade, and BMI (ERAS = 1811, Standard Care = 3549 patients). Outcomes included Length of Stay (LOS), 30-day readmission, overall infection, superficial infection, deep infection, 30- and 90-day mortality rates.

The median LOS was 1 day (IQR 1–2) in the ERAS group versus 3 days (IQR 2–4) in the Standard Care group (W = 5,415,769, P < 0.001). Rates of 30-day readmission (1.7% vs. 2.1%), overall infection (0.66% vs. 1.15%), deep infection (0.39% vs. 0.68%), superficial infection (0.28% vs. 0.48%), 30-day mortality (0.11% vs. 0.20%), and 90-day mortality (0.22% vs. 0.37%) were all higher in the Standard Care group. However, these differences were not statistically significant, with P-values of 0.41, 0.11, 0.26, 0.38, 0.70, and 0.52, respectively. The estimated cost reduction per patient with the ERAS pathway, considering only the difference in LOS, is £718.60(95%CI £602.56 to £832.64). The subgroup analysis for patients ≥ 80 revealed a statistically significant difference in LOS, which was more pronounced with a median difference of 3 days (5 days in standard care versus 2 days in ERAS, P < 0.001).

Non-selective ERAS was safe and effective in reducing LOS for patients undergoing primary THA and TKA across all age groups and varying comorbidity statuses. Although perioperative morbidity and mortality were less in ERAS, these changes did not reach statistical significance.