sACB vs cACB in TKA

Comparison of Single-shot vs. Continuous Adductor Canal Block Analgesic Effects With Catheter Positioning Confirmation in Total Knee Arthroplasty: a Double-blinded Prospective Randomized Controlled Trial

This study compares the analgesic efficacy of single-dose adductor canal block (sACB) versus continuous-dose adductor canal block (cACB) for postoperative pain management in total knee replacement patients. To ensure a high level of clinical accuracy, the investigation specifically focuses on a cACB cohort where ultrasound confirmation ensures the catheter remains correctly positioned for a full 48 hours. Participants are assigned to groups using a 1:1 randomization protocol via computer-generated tables to eliminate selection bias. Clinical consistency is maintained by using identical pharmacological agents across both groups: 0.5% Heavy Bupivacaine for spinal anesthesia and 0.5% ropivacaine with 1:200,000 epinephrine for the nerve block itself. Furthermore, both groups adhere to a standardized multimodal analgesic schedule to control for external variables. In the cACB group, intravenous patient-controlled analgesia (IV PCA) serves as a designated rescue therapy should the catheter fail. The primary technical evaluation occurs 48 hours post-surgery, utilizing ultrasound to verify catheter placement and quantify pain levels. Beyond immediate recovery, the study evaluates long-term success through Patient-Reported Outcome Measures (PROMs) at a 12-week follow-up, focusing on functional restoration and the patient's overall quality of life. By isolating the variable of catheter stability, the research aims to provide a definitive comparison of whether the continuous delivery of local anesthetic offers a statistically significant clinical advantage over a single-dose administration in the context of modern orthopedic recovery protocols.

Study Overview

• Status: Not yet recruiting
• Conditions: Arthroplasty; Knee; Replacement
• Intervention / Treatment: Procedure: Continuous ACB; Procedure: Single-shot ACB

• Study Type: Interventional
• Enrollment (Estimated): 78
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: eunjung Kim; Email: natlis@yuhs.ac

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 40-80 yrs
• Scheduled for unilateral total knee arthroplatsy
• ASA I-III
• BMI 18-35 kg/㎡
• Able to read and understand consent form

Exclusion Criteria:

• Allergy to local anesthetics
• Infection at the block site
• History of neuropathy or peripheral nerve disease
• Coagulation disorders or use of anticoagulants (if discontinuation is not possible)
• Communication disorders or cognitive impairment
• Chronic opioid use (≥30 MME/day, 3 months or more)
• Severe chronic pain (NRS ≥7/10, 3 months or more)
• Renal impairment (eGFR <30 mL/min/1.73m²)
• Hepatic impairment (Child-Pugh C)
• Blood coagulation disorders
• Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Continuous ACB	Procedure: Continuous ACB; Adductor canal block, a lower extremity nerve block technique for postoperative pain control, is performed under ultrasound guidance for patients undergoing total knee arthroplasty, and is carried out by inserting a catheter. The catheter is connected to a PCA pump following insertion, with a continuous infusion rate for two days post-surgery.
Sham Comparator: Single-shot ACB	Procedure: Single-shot ACB; Adductor canal block, a lower extremity nerve block technique for postoperative pain control, is performed under ultrasound guidance for patients undergoing total knee arthroplasty, and is carried out by a single-shot local anesthetic administration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
postoperative pain score at rest (Area Under Curve, AUC)	48-hour postoperative pain score at rest (Area Under Curve, AUC) using NRS.	postoperative 48 hours

Collaborators and Investigators

• Sponsor: Yonsei University

Study record dates

Study Major Dates

• Study Start (Estimated): May 18, 2026
• Primary Completion (Estimated): January 10, 2028
• Study Completion (Estimated): January 31, 2028

Study Registration Dates

• First Submitted: May 6, 2026
• First Submitted That Met QC Criteria: May 6, 2026
• First Posted (Actual): May 12, 2026

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 4-2026-0299

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No