Trigger Point Injection in Reducing Pain Following Total Knee Arthroplasty

This study will evaluate the ability of trigger point injections completed immediately following a total knee arthroplasty decrease pain scores and opioid use compared to sham injections. Given the current state of opioid dependency in the United States there needs to be a more focused attempt at treating post-operative pain without use of opioids. Given the manipulation of soft tissue during a total knee arthroplasty there seems to be a high correlation with pain and myofascial pain syndrome. This study will include an experimental (trigger point injection) and control (sham injection) group who are all undergoing a total knee arthroplasty. This is a pilot study that will include a maximum of 100 total patients (although it is planned for the study to be much smaller with a planned 10-15 patients per group). The procedure that will be completed is a trigger point injection with use of 1% lidocaine without epinephrine along the distal aspect of the vastus medialis and lateralis, proximal aspect of the medial and lateral gastrocnemius muscle bellies. The sham injection will be completed by pressing the needle against the skin without injecting any fluid. There will be a "blind" between the patient and the needle with both arms of the study. These patients will be followed up on POD1, and during weeks 2 and 6 follow-up where they will be given questionnaires to assess pain (visual analogue scale) and opioid use, and asked to bring their opioid medications to the clinic to assess the morphine milligrams equivalent (MME).

Study Overview

• Status: Completed
• Conditions: Trigger Point Pain, Myofascial
• Intervention / Treatment: Drug: Trigger point injection (lidocaine); Other: Sham Comparator

• Study Type: Interventional
• Enrollment (Actual): 11
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • California
    • Fairfield, California, United States, 94535
      • David Grant Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged 45 years or older
• Planned to undergo primary total knee arthroplasty
• Able to speak, read, and understand English
• Willing to complete a study questionnaires
• Willing to bring in their medications to be counted
• DoD beneficiaries
• No allergy to lidocaine
• Not fearful of needles.

Exclusion Criteria:

• Chronic opioid users (daily use of prescribed opioids for at least 90 days)
• Diagnosed with Fibromyalgia
• Non-English speaking
• Unable to read English
• Unable to understand English
• Pregnant
• Allergy to lidocaine
• Not willing to complete study questionnaires
• Not willing to bring in their medications to be counted
• Not a DoD beneficiary
• Fearful of needles

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental group - participants receiving trigger point injections; The participant will receive trigger point injections with 1% lidocaine without epinephrine in two muscles in the thigh and two muscles in the calf immediately after having knee replacement surgery.	Drug: Trigger point injection (lidocaine); A trigger point injection utilizing lidocaine 1% without epinephrine will be injected into several muscles bellies immediately following surgery to halt a trigger point from forming. One group will receive this type of intervention and the sham group will not receive any type of injection.
Sham Comparator: Sham comparator - Participants not receiving trigger point injections; The patient will not receive an injection, but instead a façade of an injection by having the same physical set-up to prepare for an injection (the same as for the experimental group), but there will be a barrier between the patient's view and the syringe so that he/she will not know an injection was not given.	Other: Sham Comparator; This arm of the study will not receive any injection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain Scores on the Visual Analog Scale	1. Change in Visual Analog Scale (VAS) pain scores The VAS is a numbered scale assessing pain severity using a number which describes the average level of pain since being discharged. Participants are to put a hash mark "/" on a numbered scale ranging from 0-100. Zero (0) is no pain and 100 is severe intolerable pain	From enrollment to the end of treatment at 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Opioid Use	1. Compare the total opioid use between study groups (experimental, sham comparator). Opioid use will be measured during their inpatient stay using the Medication Administration Record (MAR) Summary in the electronic medical record; and completing an Opioid Use questionnaire and counting the number of pills remaining during post-operative/follow-up study visits. Inpatient opioid use will be calculated by using the morphine dosage and number of doses per day. Outpatient opioid use will be obtained by reviewing responses to the Opioid Use questionnaire and counting the number of pills remaining from the prescription given at the time of discharge. Participants will be asked to bring their medication (opioids) to their post-operative/follow-up study visits. This method will allow the investigator to measure total opioid use (injectable and pill) during their inpatient and outpatient course.	From enrollment to the end of treatment at 6 weeks

Collaborators and Investigators

• Sponsor: David Grant U.S. Air Force Medical Center
• Investigators: Principal Investigator: Dustin L Bennett, David Grant

Study record dates

Study Major Dates

• Study Start (Actual): May 30, 2025
• Primary Completion (Actual): August 25, 2025
• Study Completion (Actual): August 26, 2025

Study Registration Dates

• First Submitted: April 25, 2025
• First Submitted That Met QC Criteria: April 25, 2025
• First Posted (Actual): May 2, 2025

Study Record Updates

• Last Update Posted (Actual): February 12, 2026
• Last Update Submitted That Met QC Criteria: January 26, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Muscular Diseases; Myofascial Pain Syndromes; Organic Chemicals; Anilides; Amides; Aniline Compounds; Amines; Acetanilides; Lidocaine
• Other Study ID Numbers: FDG20240079H

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No