Continuous Versus Single Injection Adductor Canal Blocks for Outpatient Total Knee Arthroplasty

NCT ID: NCT06784882

Last Updated: 2025-06-17

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE4
• Total Enrollment: 40 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-06-01
• Study Completion Date: 2025-12-01

Brief Summary

This is a single-center pilot study to determine if an adductor canal continuous nerve block is superior to single injection nerve block following total knee arthroplasty. Investigators will randomize participants to either continuous nerve block or single injection nerve block for the adductor canal preoperatively. They will assess differences in pain (measured in numeric rating scale), opioid consumption, and physical therapy milestones from postoperative day 0 to 7.

Detailed Description

Adductor canal blocks are standard care for postoperative analgesia following total knee arthroplasty. Adductor canal blocks involve depositing local anesthetic (ropivacaine) around the saphenous nerve at the location of the adductor canal on the ipsilateral thigh. At UCSD, the standard care is to perform single injection adductor canal blocks for research participants undergoing total knee arthroplasty prior to surgery in the preoperative waiting area.

Participants will be randomized to either: (1) single injection with ropivacaine (0.5%) of the adductor canal block AND a 5-day continuous perineural infusion of ropivacaine (0.2%) (experimental group); versus (2) single injection with ropivacaine (0.5%) of the adductor canal block and no continuous nerve block added.

Conditions

Acute Postoperative Pain; Surgery

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Continuous adductor canal block

single injection with ropivacaine (0.5%) of the adductor canal block and a 5-day continuous perineural infusion of ropivacaine (0.2%) (experimental group)

Group Type: EXPERIMENTAL

continuous peripheral nerve block with OnQ pump

Intervention Type: DEVICE

For continuous nerve blocks, the infusion pump that will be used are OnQ pumps (Avanos, Alpharetta, GA) and pre-filled with ropivacaine 0.2% and provided by UCSD's Investigational Drug Services.

single injection adductor canal block

single injection with ropivacaine (0.5%) of the adductor canal block and no continuous nerve block added

Group Type: ACTIVE_COMPARATOR

single injection nerve block

Intervention Type: DRUG

An adductor canal single injection nerve block will be performed per standard of care. The adductor canal will be identified by ultrasound in the short-axis view. The distal aspect of the femoral triangle (and beginning of the adductor canal) will be identified distal to the mid-thigh in the ipsilateral limb. Using ultrasound guidance, a standard Tuohy block needle will be advanced through a skin wheal of lidocaine until its tip is in the hypoechoic area immediately distal saphenous nerve adjacent to the femoral artery. Twenty milliliters of ropivacaine 0.5% will be injected in divided doses with repeated negative aspiration.

Interventions

continuous peripheral nerve block with OnQ pump

For continuous nerve blocks, the infusion pump that will be used are OnQ pumps (Avanos, Alpharetta, GA) and pre-filled with ropivacaine 0.2% and provided by UCSD's Investigational Drug Services.

Intervention Type: DEVICE

single injection nerve block

An adductor canal single injection nerve block will be performed per standard of care. The adductor canal will be identified by ultrasound in the short-axis view. The distal aspect of the femoral triangle (and beginning of the adductor canal) will be identified distal to the mid-thigh in the ipsilateral limb. Using ultrasound guidance, a standard Tuohy block needle will be advanced through a skin wheal of lidocaine until its tip is in the hypoechoic area immediately distal saphenous nerve adjacent to the femoral artery. Twenty milliliters of ropivacaine 0.5% will be injected in divided doses with repeated negative aspiration.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

1. Adult participants of at least 18 years of age

2. Undergoing a primary, unilateral, total knee arthroplasty

3. Planned single-injection adductor canal nerve block

4. Weight > 50 kg (to minimize the risk of local anesthetic toxicity)

Exclusion Criteria

1. chronic opioid or tramadol use: daily oxycodone equivalents > 20 mg for > 4 weeks

2. neuro-muscular deficit of the surgical limb

3. moderate pain (NRS > 3) in an anatomic location other than the surgical site

4. planned hospital admission following surgery

5. history of opioid misuse

6. those who lack capacity to complete informed consent

7. inability to contact the investigators during the treatment period, and vice versa (e.g., lack of telephone access)

8. incarceration

9. pregnancy

10. allergy to amide local anesthetics

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of California, San Diego

OTHER

Sponsor Role: lead

Responsible Party

Rodney Gabriel

Associate Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

University of California, San Diego

La Jolla, California, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Rodney A Gabriel, MD

Role: CONTACT

ragabriel@health.ucsd.edu

858-663-7747

Facility Contacts

Rodney Gabriel

Role: primary

ragabriel@health.ucsd.edu

8586637747

References

Chou R, Gordon DB, de Leon-Casasola OA, Rosenberg JM, Bickler S, Brennan T, Carter T, Cassidy CL, Chittenden EH, Degenhardt E, Griffith S, Manworren R, McCarberg B, Montgomery R, Murphy J, Perkal MF, Suresh S, Sluka K, Strassels S, Thirlby R, Viscusi E, Walco GA, Warner L, Weisman SJ, Wu CL. Management of Postoperative Pain: A Clinical Practice Guideline From the American Pain Society, the American Society of Regional Anesthesia and Pain Medicine, and the American Society of Anesthesiologists' Committee on Regional Anesthesia, Executive Committee, and Administrative Council. J Pain. 2016 Feb;17(2):131-57. doi: 10.1016/j.jpain.2015.12.008.

Reference Type: BACKGROUND

PMID: 26827847 (View on PubMed)

Other Identifiers

811228

Identifier Type: -

Identifier Source: org_study_id