Continuous versus single adductor canal nerve block for outpatient total knee replacement

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

Phase 4 Interventional University of California, San Diego · NCT06784882

This test checks whether adding a 5-day continuous adductor canal nerve block to the usual single injection lowers pain and opioid use after outpatient total knee replacement.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment40 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of California, San Diego Academic / other
Locations1 site (La Jolla, California)
Trial IDNCT06784882 on ClinicalTrials.gov

What this trial studies

This single-center, randomized pilot at UC San Diego will enroll adults having primary, unilateral outpatient total knee arthroplasty and randomize them to either a single‑injection adductor canal block alone or the same single injection plus a 5‑day continuous perineural infusion of ropivacaine via an OnQ pump. Pain scores (numeric rating scale), opioid consumption, and physical therapy milestones will be recorded from postoperative day 0 through day 7. Eligibility excludes chronic opioid users above a modest threshold, patients with neuromuscular deficits of the surgical limb, planned admission after surgery, pregnancy, and allergy to amide local anesthetics. The goal is to see if the continuous infusion provides better early analgesia and functional progress than a single injection alone.

Who should consider this trial

Good fit: Adults (≥18 years) undergoing a primary, unilateral outpatient total knee arthroplasty who are planned for a single‑injection adductor canal block, weigh more than 50 kg, and do not have exclusion criteria such as chronic high‑dose opioid use or local anesthetic allergy.

Not a fit: Patients with chronic opioid dependence, neuromuscular deficits in the surgical limb, planned inpatient admission, allergy to amide local anesthetics, or those unable to be contacted during the treatment period are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, adding a continuous adductor canal block could reduce postoperative pain, decrease opioid requirements, and help patients reach physical therapy goals sooner after knee replacement.

How similar studies have performed: Prior studies of continuous peripheral nerve infusions for knee arthroplasty have shown improved short‑term pain control and reduced opioid use in some reports, but results are mixed and outpatient‑specific evidence remains limited.

Eligibility criteria

Show full inclusion / exclusion 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

Where this trial is running

La Jolla, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Acute Postoperative PainSurgeryregional anesthesiatotal knee arthroplastynerve block
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.