Skip to main content
OpenTrials
Recruiting

NCT Number: NCT06784882

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

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.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Acute Postoperative Pain Neurologic Manifestations Pain Pain, Postoperative Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Complications Signs and Symptoms Surgery

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

University of California, San Diego

La Jolla, California, 92037, United States

Location status: Recruiting

Location contact

Rodney Gabriel

CONTACT

[email protected]

8586637747

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult participants of at least 18 years of age
  • Undergoing a primary, unilateral, total knee arthroplasty
  • Planned single-injection adductor canal nerve block
  • Weight > 50 kg (to minimize the risk of local anesthetic toxicity)

Exclusion criteria

  • chronic opioid or tramadol use: daily oxycodone equivalents > 20 mg for > 4 weeks
  • neuro-muscular deficit of the surgical limb
  • moderate pain (NRS > 3) in an anatomic location other than the surgical site
  • planned hospital admission following surgery
  • history of opioid misuse
  • those who lack capacity to complete informed consent
  • inability to contact the investigators during the treatment period, and vice versa (e.g., lack of telephone access)
  • incarceration
  • pregnancy
  • allergy to amide local anesthetics

Treatment and study plan

continuous peripheral nerve block with OnQ pump

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 nerve block

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.

Primary outcomes

  1. analgesic effect of 5-day continuous nerve block of the adductor canal relative to a single inection nerve block with ropivacaine.

    Time frame: 7 days

    Numeric Rating Scale (NRS) for pain will be superior daily with continuous adductor canal blocks on postoperative days 1-7 following total ankle arthroplasty as compared with single-injection adductor canal blocks (as measured by the "average" daily NRS within the Brief Pain Inventory)

  2. opioid consumption of 5-day continuous nerve block of the adductor canal relative to a single inection nerve block with ropivacaine.

    Time frame: 7 days

    Opioid consumption will be superior daily with continuous adductor canal blocks on postoperative days 1-7 following total ankle arthroplasty as compared with single-injection adductor canal blocks (measured in oxycodone equivalents)

Secondary outcomes

  1. physical and emotional functioning of 5-day continuous nerve blocks relative to a single injection nerve blocks with ropivacaine

    Time frame: 7 days

    The physical and emotional functioning of research participants will be superior daily with continuous adductor canal blocks on postoperative days 1-7 following total ankle arthroplasty as compared with single-injection adductor canal blocks (as measured with the Brief Pain Inventory Interference Subscale)

  2. improvement in physical therapy milestones of 5-day continuous nerve blocks relative to a single injection nerve blocks with ropivacaine

    Time frame: 30 days

    Knee injury and osteoarthritis outcome score for joint replacement (KOOS JR)

  3. 30-day pain score measured in Numeric Rating Scale

    Time frame: 30 days

    At around 30 days postoperatively, the patients average pain score measured in the numeric rating scale (0-10) will be assessed.

  4. 30-day postoperative opioid consumption

    Time frame: 30 days

    Around 30 days postoperatively, the average opioid consumption will be assessed. This will be based on the average opioid consumption over the preceding week at 30 days.

Study contacts

Contact information is provided by the study sponsor or research team.

Rodney A Gabriel, MD

CONTACT

[email protected]

858-663-7747

Sponsors and collaborators

Lead sponsor

University of California, San Diego

Other

Registry information

Official study title

A Pilot Randomized Controlled Trial Assessing Pain and Opioid Outcomes Among Patients Undergoing Total Knee Arthroplasty Receiving 5-Day Outpatient Adductor Canal Continuous Versus Single Injection Blocks

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Jan 20, 2025
Registry last updated
Jun 17, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.