NCT06784882 · University of California, San Diego
Continuous Versus Single Injection Adductor Canal Blocks for Outpatient Total Knee Arthroplasty
What this study is about
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.
View original scientific description
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.
Interventions
DEVICE
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.
DRUG
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.
Primary outcome measures
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)
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)
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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
- allergy to amide local anesthetics
Where
- La Jolla, California
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 17, 2025 · Source of record for eligibility and locations