Pilot Study on EXPAREL as an Intra-articular Posteromedial Surgeon Administered (IPSA) Block vs. Local Infiltration Analgesia in Knee Replacement Surgery (CRS-121)

May 7, 2026 updated by: Andrew Spitzer, Cedars-Sinai Medical Center

A Prospective, Single-Center, Randomized, Pilot Study to Assess the Clinical Effectiveness of EXPAREL as an Intra-articular Posteromedial Surgeon Administered (IPSA) Block Compared to Local Infiltration Analgesia in Subjects Undergoing Primary Unilateral Total Knee Arthroplasty

The study aims to test the safety and effectiveness of two different surgeon-administered methods of the anesthesia medication EXPAREL during knee replacement surgery. This study will not determine whether one method is better than the other, but will instead help the study investigator decide if both methods can provide an equal amount of pain relief.

The main question this study aims to answer is:

Will EXPAREL provide an equal amount of pain relief for patients who receive EXPAREL via Intra-articular Posteromedial Surgeon Administered (IPSA) Block and patients that receive EXPAREL via Local Infiltration Analgesia (LIA)?

Following their surgery, participants will be asked to report their pain level on their treated knee using a numerical rating scale (NRS) between 0 to 10. In addition to their pain level, participants will report any medications used for pain relief and will mark specific regions on an image to indicate where they experience pain.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Los Angeles, California, United States, 90048
        • Cedars-Sinai Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 18 years of age or older
  • Scheduled to undergo total knee arthroplasty (TKA) under spinal anesthesia
  • Primary indication for TKA is degenerative osteoarthritis of the knee
  • Able to provide informed consent, adhere to the study schedule, and complete all study assessments
  • Body Mass Index (BMI) ≥18 and <40 kg/m2

Exclusion Criteria:

  • Allergy, hypersensitivity, intolerance, or contraindication to any of the study medications for which an alternative is not named in the protocol (e.g., amide-type local anesthetics, opioids, bupivacaine HCl, NSAIDs)
  • Planned concurrent surgical procedure
  • Undergoing knee surgery for a single area of the knee or a revision surgery
  • History of knee replacement surgery within the past 6 months
  • History of, suspected, or known addiction to or abuse of illicit drug(s), prescription medicine(s), or alcohol within the past 2 years
  • Previous participation in an EXPAREL study
  • Uncontrolled anxiety, schizophrenia, or other psychiatric disorder that, in the opinion of the Investigator, could interfere with study assessments or compliance
  • Currently pregnant, nursing, or planning to become pregnant during the study
  • Any individual who, per standard of care, is excluded from the surgery due to possibility of pregnancy.
  • Male participant in a sexually active relation with pregnant or breastfeeding partner
  • Clinically significant medical disease that, in the opinion of the Investigator, would make participation in a clinical study inappropriate.
  • Any use of marijuana [including Tetrahydrocannabinol (THC) and Cannabidiol (CBD)] within 30 days prior to randomization, or planned use during the course of the study
  • Chronic opioid use within 30 days prior to surgery

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group 1 - Study Group
Group 1 will be assigned to receive the IPSA Block which is an innovative surgeon technique to administer anesthesia to a treated knee joint and will include the standard technique known as Local Infiltration Analgesia (LIA).
Procedure: Intra-articular Posteromedial Surgeon Administered (IPSA) Block with LIA
The IPSA block is a specific surgeon technique which involves providing an injection of EXPAREL to the back of the knee, reaching into the joint space to provide pain relief. This arm will also receive the LIA procedure.
Drug: Bupivacaine liposome injectable suspension (IPSA block)
Group 1 will be given an IPSA block using 10 mL of EXPAREL mixed with 10 mL of bupivacaine HCl 0.5%. An injection around the knee joint will be given as well utilizing a cocktail of: 10 mL of EXPAREL, 10 mL of bupivacaine HCl 0.5%, and 40 mL normal saline.
Active Comparator: Group 2 - Control Group
Group 2 will be assigned to receive Local Infiltration Analgesia (LIA) which is the standard anesthesia administration technique used for patients undergoing knee replacement surgery.
Procedure: Local Infiltration Analgesia (LIA)
The local infiltration analgesia (LIA) procedure involves the administration of anesthesia with the use of several needle sticks to areas surrounding the knee joint.
Drug: Bupivacaine liposome injectable suspension (LIA)
Group 2 will be given LIA with EXPAREL 20 mL (266 mg) mixed with 20 mL bupivacaine HCL 0.5% and 80 mL normal saline (total volume of 120 mL).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Post-Operative Pain Scores
Time Frame: Study participants will report Numerical Rating Scale (NRS) pain intensity scores throughout various timepoints between 0 to 72 hours post-surgery.
The primary outcome measure will be the Numerical Rating Scale (NRS) pain intensity scores reported by study participants. These results will be compared between both treatment groups.
Study participants will report Numerical Rating Scale (NRS) pain intensity scores throughout various timepoints between 0 to 72 hours post-surgery.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Cedars-Sinai Medical Center

Collaborators

Pacira Pharmaceuticals, Inc

Investigators

  • Principal Investigator: Andrew I Spitzer, MD, Cedars-Sinai Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 1, 2026

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

August 1, 2026

Study Registration Dates

First Submitted

May 7, 2026

First Submitted That Met QC Criteria

May 7, 2026

First Posted (Actual)

May 13, 2026

Study Record Updates

Last Update Posted (Actual)

May 13, 2026

Last Update Submitted That Met QC Criteria

May 7, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Pro00003735

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All de-identified IPD related to the study protocol will be shared.

IPD Sharing Time Frame

IPD will be available between April 1, 2026 until the end of the study.

IPD Sharing Access Criteria

Access to individual participant data will be limited to collaborators (ie, Pacira) collaborating as defined in the collaborative agreement. De-identified or coded data will be shared solely for analyses related to the objectives of the study. Data will not be made publicly available or shared with external third parties.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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