Comparative Effects of Two Periarticular Analgesic Cocktails on Pain Reduction and Inflammatory Response After Unicompartmental Knee Arthroplasty

Summary

This study aimed to compare and analyze the analgesic effect, anti‑inflammatory activity, and safety of two ropivacaine‑based periarticular analgesic cocktails in patients undergoing UKA. Following propensity score-matching, the ropivacaine-ketorolac-epinephrine regimen provided better analgesia, anti-inflammatory effects, and functional recovery, with comparable safety.

Abstract

Unicompartmental knee arthroplasty (UKA) serves as the primary surgical treatment for isolated unicompartmental knee osteoarthritis. Clinical data of 108 patients who underwent UKA at Yueyang People’s Hospital from January 2020 to December 2024 were retrospectively screened. After strict case exclusion, 102 patients were categorized into Group A (ropivacaine combined with morphine and compound betamethasone, n = 52) and Group B (ropivacaine combined with ketorolac tromethamine and epinephrine, n = 50). Propensity score matching (PSM) was subsequently performed to balance baseline characteristics, resulting in 46 patients per group after matching. Primary outcomes consisted of resting and active visual analog scale (VAS) scores, 48 h postoperative opioid consumption, and inflammatory biomarkers, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell (WBC), and neutrophil (NEUT) levels. Secondary outcomes covered knee range of motion (ROM), time to initial postoperative ambulation, Knee Injury and Osteoarthritis Outcome Score (KOOS), Barthel Index (BI), and postoperative adverse events. Baseline parameters were well balanced between the two groups following PSM (all P > 0.05). At 48 h postoperatively, Group B presented significantly decreased resting and active VAS scores, as well as lower 48 h opioid consumption (all P < 0.001). Milder elevations of CRP, ESR, WBC, and NEUT were observed in Group B (all P < 0.001). Additionally, Group B demonstrated superior knee functional recovery reflected by better ROM, higher KOOS and BI scores, and shorter time to first ambulation (all P < 0.001). No significant intergroup difference was detected in the incidence of adverse events (P = 0.503). In this single-center retrospective cohort, the ropivacaine–ketorolac–epinephrine cocktail demonstrates superior analgesic and anti-inflammatory properties with a noninferior safety profile. Limited by the single-center, retrospective design, this regimen is preliminarily considered a promising analgesic alternative for UKA patients, and further large-sample, multicenter, prospective studies are required for validation.

Introduction

The escalating global aging trend has driven a steady increase in the incidence of knee osteoarthritis (KOA), with the prevalence exceeding 10 % in individuals aged ≥ 60 years¹. Among these, approximately 30 % of patients present with isolated unicompartmental lesions, for which unicompartmental knee arthroplasty (UKA) has emerged as an ideal alternative to total knee arthroplasty², offering minimal invasiveness, reduced blood loss, near-physiological knee range of motion (ROM), and accelerated rehabilitation³.

However, postoperative pain remains a critical barrie....

Protocol

This study was reviewed and approved by the Medical Ethics Committee of Yueyang People’s Hospital (Ethical Approval No.: ky2025012), and all procedures were performed in strict accordance with the Declaration of Helsinki¹⁴.

1. Patients and methods

1. Retrieve medical records of 108 patients who underwent UKA at Yueyang People’s Hospital from January 2020 to December 2024.
2. Enroll 102 patients after exclusions.
   1. Divide them into Group A (ropivacaine + morphine + compound betamethasone, n = 52) and Group B (ropivacaine + ketorolac tromethamine + epinephrine, n =....

Results

Baseline characteristics of patients

Table 1 shows baseline characteristics before and after PSM. Before matching, Group A included 52 patients and Group B 50 patients. PSM was performed using a logistic regression model with age, gender, BMI, ASA classification, lesion site, K-L grading, hypertension, diabetes, and CHD as covariates; only main effects were included without interaction or nonlinear terms. Prior to PSM, gender, BMI, and hypertension differed si.......

Discussion

UKA represents a precision surgical procedure for the treatment of unicompartmental knee osteoarthritis. Currently, multimodal analgesia regimens based on ropivacaine are widely adopted in clinical practice, achieving synergistic analgesic effects through the combination of drugs with distinct mechanisms of action. However, differences in postoperative analgesic intensity, anti-inflammatory efficacy, and safety persist among analgesic cocktails with varying drug combinations²⁸. This retrospective .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
1% ropivacaine hydrochloride injection	AstraZeneca Pharmaceuticals LP	H20140763	drug
morphine sulfate injection	Shenyang No.1 Pharmaceutical Co., Ltd.	H21022436	drug
compound betamethasone injection	Merck Sharp & Dohme Corp.	H20180023	drug
ketorolac tromethamine injection	Shandong New Times Pharmaceutical Co., Ltd.	H20052634	drug
epinephrine hydrochloride injection	Shanghai Hefeng Pharmaceutical Co., Ltd.	H31021170	drug
VAS ruler	Shanghai Medical Devices Co., Ltd.	SY-VAS-01	scale
patient-controlled intravenous analgesia pump	Zhuhai Funia Medical Equipment Co., Ltd.	FCS-6000	Instrument
automatic biochemical analyzer	Roche Diagnostics	Cobas 8000	Instrument
automatic Erythrocyte sedimentation rate analyzer	Beijing Succeeder Technology Co., Ltd.	ESR-600	Instrument
automatic hematology analyzer	Mindray	BC-6800	Instrument
standard goniometer	Guilin Guanglu Digital Measurement & Control Co., Ltd.	GL-100	Instrument
G*Power	Heinrich - Heine - Universität Düsseldorf	3.1.9.7	software
SPSS software	IBM	SPSS 27.0	software
Doppler ultrasonography	Philips Healthcare	EPIQ 7	Instrument
20 mL disposable syringe	Becton, Dickinson and Company	300613	syringe
22G long needle of 38 mm in length	Terumo Medical Corporation	NN-2238R	syringe
0.9% sodium chloride injection	China National Biotec Group	S20053046	drug