Recruiting

Zynrelef, ACB & PAI

Sponsor:

Henry Ford Health System

Code:

NCT07775248

Conditions

Osteoarthritis (OA) of the Knee

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Periarticular Injection

Adductor Canal Block

Bupivacaine-Meloxicam

Study Details

Brief summary:

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.

Conditions

Osteoarthritis (OA) of the Knee

Study ID

NCT07775248

Start date

Feb 11, 2025

Status verified date

Aug, 2026

Completion date

Oct 20, 2026

Anticipated

Primary completion date

Oct 20, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

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

Study Design

Enrollment

150 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: Periarticular Injection

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.

active comparator: Adductor Canal Block

(adductor canal block) will receive an adductor canal block in the preoperative bay.

active comparator: Bupivacaine-Meloxicam

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.

Interventions

Periarticular Injection

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.

Adductor Canal Block

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.

Bupivacaine-Meloxicam

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.

Primary outcome measure

  • Postoperative Pain Score Assessed Using the Numeric Rating Scale (NRS) [ Time Frame: Postoperative Day 0-Postoperative Day 5 ]

Central Contacts and Locations

Locations

Henry Ford Medical Center - Grosse Pointe Cottage

Recruiting

Grosse Pointe Farms, Michigan, United States, 48236

Contacts

Trevor North, MD

313 916 9388tnorth1@hfhs.org

More Information

Sponsor

Henry Ford Health System

Last update posted

Aug 20, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Henry Ford Health System on 2026-08-20.