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

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

Status
Recruiting
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07775248
Enrollment
150
Registered
2026-08-20
Start date
2025-02-11
Completion date
2026-10-20
Last updated
2026-08-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Osteoarthritis (OA) of the Knee

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.

Interventions

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.

DRUGAdductor 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.

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.

Sponsors

Henry Ford Health System
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frameDescription
Postoperative Pain Score Assessed Using the Numeric Rating Scale (NRS)Postoperative Day 0-Postoperative Day 5Postoperative 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

MeasureTime frameDescription
Emergency Department Visits90 days post-opAny unplanned emergency department visit occurring within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.
Mortality90 days post-opAny cause of death occurring within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.
Postoperative Unplanned Readmission90 days post-opAny unplanned hospital readmission occurring within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.
Return to Operating Room90 days post-opAny 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.
Number of Participants with Hardware Failure of Implanted Prosthetic Components90 days post-opAny 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.
Number of Participants with Periprosthetic or Perioperative Fracture90 days post-opAny periprosthetic or perioperative fracture occurring within 90 days of total knee arthroplasty, as identified through chart review and imaging.
Number of Participants with Postoperative Dislocation of the Prosthetic Joint90 days post-opAny dislocation of the prosthetic joint occurring within 90 days of total knee arthroplasty, as identified through chart review and the electronic medical record.
Number of Participants with Periprosthetic Joint Infection (PJI)90 days post-opAny 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.
Number of Participants with Postoperative Hematoma90 days post-opAny 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.

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 21, 2026