Skip to main content
OpenTrials
Recruiting

NCT Number: NCT07775248

Novel Extended-Release Bupivacaine Polymer for Sustained Pain Relief Following Total Knee Arthroplasty

Participants are being invited to take part in a research study about pain control after total knee replacement surgery (also called total knee arthroplasty or TKA). The goal of this study is to see if a new long-acting medication, called Zynrelef, can control pain after surgery as well as or better than two other common pain treatments - a nerve block or a standard injection into the knee during surgery.

Knee replacement is done to reduce pain and improve movement in people with severe knee arthritis. While the surgery can be very successful, pain during the first few days after surgery can make recovery harder. Many patients need strong opioid pain medicines, but these medicines can have side effects and may lead to dependence. The investigators want to find ways to control pain that reduce or even remove the need for opioids.

If participants join this study, they will be randomly placed (like flipping a coin) into one of three groups:

Standard injection (PAI) - a mix of medicines injected into the knee during surgery.

Zynrelef - a new long-acting medicine put directly into the knee during surgery, along with a smaller dose of the standard injection.

Nerve block (ACB) - medicine given near a nerve in the leg before surgery to block pain.

All participants will get the same medicines before and after surgery, follow the same physical therapy program, and have the same follow-up visits. Participants will be asked to record their pain scores and the pain medicines they take for several weeks after surgery.

The risks of joining are small and similar to those of routine care. All three pain control methods are already used in regular knee replacement surgery. Possible side effects may include temporary numbness, weakness, or soreness from the injections, and the usual surgical risks such as infection.

Participants may benefit from better pain control, less need for opioids, and a smoother recovery. The results from this study may also help future patients have safer and more comfortable knee replacements.

Taking part is voluntary. Participants can leave the study at any time without affecting their medical care.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Osteoarthritis (OA) of the Knee Arthritis Joint Diseases Musculoskeletal Diseases Osteoarthritis Rheumatic Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Henry Ford Medical Center - Grosse Pointe Cottage

Grosse Pointe Farms, Michigan, 48236, United States

Location status: Recruiting

Location contact

Trevor North, MD

CONTACT

[email protected]

313 916 9388

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Adult patients age 18 and older undergoing primary total knee replacement by fellowship trained Orthopedic Surgeons in Henry Ford Health System with planned outpatient same-day discharge.

Exclusion criteria

  • Incomplete data in medical records
  • Non-English speakers
  • Chronic opioid use in the last 3 months
  • Ipsilateral joint surgery in the last year
  • Undergoing bilateral knee arthroplasty
  • Cannot tolerate oral medications
  • Swallowing difficulties
  • Intolerance to acetaminophen, anti-inflammatories, muscle relaxants, gabapentinoids, or opioids/tramadol
  • History of alcohol abuse
  • Drug abuse
  • Renal impairment
  • Peptic ulcer disease
  • GI bleeding
  • Illicit narcotic usage in the past 6 months
  • Chronic liver disease
  • Chronic pain syndromes

Treatment and study plan

Periarticular Injection

Drug

Study group I (standard PAI) will receive an intraoperative periarticular injection consisting of 300mg of 0.5% ropivacaine with 1mg epinephrine and 30mg ketorolac in sodium chloride 0.9% diluted to a volume of 120ml.

Other names: Periarticular Injection (PAI)

Adductor Canal Block

Drug

Patients randomized to the adductor canal block (ACB) arm will receive a preoperative ACB administered by an anesthesia provider prior to total knee arthroplasty, with additional ropivacaine administered to the posterior capsule per standard protocol.

Other names: Saphenous Nerve Block, Subsartorial Block

Bupivacaine-Meloxicam

Drug

will receive the extended-release bupivacaine injected into the effective knee joint space prior to closure, combined with an abbreviated PAI of half dose (150mg ropivacaine) to act as a bridge per standard recommendation.

Other names: Zynrelef

Primary outcomes

  1. Postoperative Pain Score Assessed Using the Numeric Rating Scale (NRS)

    Time frame: Postoperative Day 0-Postoperative Day 5

    Postoperative pain will be assessed using the Numeric Rating Scale (NRS), an 11-point scale ranging from 0 (no pain) to 10 (worst pain imaginable). Higher scores indicate worse pain outcomes. Pain scores will be recorded daily by participants from postoperative day 0 through postoperative day 5.

Secondary outcomes

  1. Emergency Department Visits

    Time frame: 90 days post-op

    Any unplanned emergency department visit occurring within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.

  2. Mortality

    Time frame: 90 days post-op

    Any cause of death occurring within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.

  3. Postoperative Unplanned Readmission

    Time frame: 90 days post-op

    Any unplanned hospital readmission occurring within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.

  4. Return to Operating Room

    Time frame: 90 days post-op

    Any unplanned return to the operating room for any reason within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.

  5. Number of Participants with Hardware Failure of Implanted Prosthetic Components

    Time frame: 90 days post-op

    Any mechanical failure of implanted prosthetic components, including loosening, breakage, or malposition, occurring within 90 days of total knee arthroplasty, as identified through chart review and imaging.

  6. Number of Participants with Periprosthetic or Perioperative Fracture

    Time frame: 90 days post-op

    Any periprosthetic or perioperative fracture occurring within 90 days of total knee arthroplasty, as identified through chart review and imaging.

  7. Number of Participants with Postoperative Dislocation of the Prosthetic Joint

    Time frame: 90 days post-op

    Any dislocation of the prosthetic joint occurring within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.

  8. Number of Participants with Periprosthetic Joint Infection (PJI)

    Time frame: 90 days post-op

    Any prosthetic joint infection diagnosed within 90 days of total knee arthroplasty per established diagnostic criteria, as identified through chart review, laboratory findings, and the electronic medical record.

  9. Number of Participants with Postoperative Hematoma

    Time frame: 90 days post-op

    Any hematoma formation at the surgical site requiring clinical intervention or documentation within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.

Sponsors and collaborators

Lead sponsor

Henry Ford Health System

Other

Registry information

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Aug 20, 2026
Registry last updated
Aug 20, 2026

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.