Trial Outcomes & Findings for Trigger Point Injection in Reducing Pain Following Total Knee Arthroplasty (NCT NCT06955923)

Last Updated: 2026-02-12

Results Overview

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

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

11 participants

Primary outcome timeframe

From enrollment to the end of treatment at 6 weeks

Results posted on

2026-02-12

Participant Flow

Participant milestones

Participant milestones
Measure	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.	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.
Overall Study STARTED	6	5
Overall Study Post Operative Day (POD) 1	6	5
Overall Study Week 2	6	5
Overall Study Week 6	3	3
Overall Study COMPLETED	3	3
Overall Study NOT COMPLETED	3	2

Reasons for withdrawal

Reasons for withdrawal
Measure	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.	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.
Overall Study Limited timeline for follow-up restricted total number of participants for the last follow-up interv	3	2

Baseline Characteristics

Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Experimental Group - Participants Receiving Trigger Point Injections n=6 Participants 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.	Sham Comparator - Participants Not Receiving Trigger Point Injections n=5 Participants 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.	Total n=11 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=6 Participants • Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research	0 Participants n=5 Participants • Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research	0 Participants n=11 Participants • Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research
Age, Categorical Between 18 and 65 years	2 Participants n=6 Participants • Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research	1 Participants n=5 Participants • Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research	3 Participants n=11 Participants • Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research
Age, Categorical >=65 years	4 Participants n=6 Participants • Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research	4 Participants n=5 Participants • Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research	8 Participants n=11 Participants • Due to the total knee replacements not being conducted on 18 year olds or younger this demographic was not considered in our research
Sex: Female, Male Female	1 Participants n=6 Participants	2 Participants n=5 Participants	3 Participants n=11 Participants
Sex: Female, Male Male	5 Participants n=6 Participants	3 Participants n=5 Participants	8 Participants n=11 Participants
BMI	28.07 kg/m^2 STANDARD_DEVIATION 2.15 • n=6 Participants	33.84 kg/m^2 STANDARD_DEVIATION 4.29 • n=5 Participants	30.96 kg/m^2 STANDARD_DEVIATION 3.22 • n=11 Participants
Number of Participants who are Military Retired or Military Dependents Dependents	1 Participants n=6 Participants	2 Participants n=5 Participants	3 Participants n=11 Participants
Number of Participants who are Military Retired or Military Dependents Retired	5 Participants n=6 Participants	3 Participants n=5 Participants	8 Participants n=11 Participants
Race and Ethnicity Not Collected	—	—	0 Participants Race and Ethnicity were not collected from any participant.

PRIMARY outcome

Timeframe: From enrollment to the end of treatment at 6 weeks

Population: Limited timeline for follow-up restricted total number of participants for the last follow-up interval (6 week)

Outcome measures

Outcome measures
Measure	Experimental Group - Participants Receiving Trigger Point Injections n=6 Participants 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.	Sham Comparator - Participants Not Receiving Trigger Point Injections n=5 Participants 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.
Pain Scores on the Visual Analog Scale Change from Baseline to Post Operative Day (POD) 1	51 Pain Scores on the Visual Analog Scale Standard Deviation 29.51	55 Pain Scores on the Visual Analog Scale Standard Deviation 22.64
Pain Scores on the Visual Analog Scale Change from POD1 to week 2 follow-up	40 Pain Scores on the Visual Analog Scale Standard Deviation 14.49	42 Pain Scores on the Visual Analog Scale Standard Deviation 24.9
Pain Scores on the Visual Analog Scale Change from week 2 to week 6 follow-up	30 Pain Scores on the Visual Analog Scale Standard Deviation 32.79	28.33 Pain Scores on the Visual Analog Scale Standard Deviation 18.93

SECONDARY outcome

Timeframe: From enrollment to the end of treatment at 6 weeks

Population: Due to time constraints our study was only able to evaluate 3 participants in each arm of the study on the 6 week post-operative appointment.

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.

Outcome measures

Outcome measures
Measure	Experimental Group - Participants Receiving Trigger Point Injections n=6 Participants 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.	Sham Comparator - Participants Not Receiving Trigger Point Injections n=5 Participants 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.
Opioid Use POD1	50.08 MME Standard Deviation 36.89	68.60 MME Standard Deviation 33.8
Opioid Use week 2	23.09 MME Standard Deviation 12.21	19.09 MME Standard Deviation 16.69
Opioid Use week 6	1.33 MME Standard Deviation 2.1	0 MME Standard Deviation 0

Adverse Events

Experimental Group - Participants Receiving Trigger Point Injections

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Sham Comparator - Participants Not Receiving Trigger Point Injections

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dustin Bennett

U.S. Air Force

Phone: 707-423-3568

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place