Trial Outcomes & Findings for C-RFA of Residual Limb Neuroma (NCT NCT04538417)

Last Updated: 2025-01-08

Results Overview

Presented here is the proportion of participants reporting ≥50% improvement in Numeric Rating Scale pain score at 6 months after their cooled radiofrequency ablation procedure. The Numeric Rating Scale was used to quantify neuroma-associated residual limb pain by asking patients to rate their pain intensity on an 11-point scale ranging from 0 to 10, with 0 representing "no pain at all" and 10 representing "the worst pain imaginable".

Recruitment status

COMPLETED

Study phase

Target enrollment

8 participants

Primary outcome timeframe

6 months

Results posted on

2025-01-08

Participant Flow

Participant milestones

Participant milestones
Measure	Residual Limb Pain in Affected Amputated Limb Patient has residual limb pain in amputated limb and is scheduled to receive standard of care treatment of cooled radiofrequency ablation. Cooled Radiofrequency Ablation: RFA procedures will be performed with modification accounting for appropriate C-RFA technique. Participant will be positioned prone and skin prepped with chloroprep. Ultrasound probe will be placed on residual limb at a transverse angle in order to view the nerve and associated neuroma in long-axis. The probe will be advanced to the site of the stump neuroma. C-RFA electrode will be placed adjacent to neuroma. Needle will be connected via wire to a cooled radiofrequency generator. Motor and sensory testing will be performed to reproduce or exacerbate the RLP and / or PLP. At the site of the neuroma, 2 mL of local anesthetic will be injected through the needle. C-RFA lesions will be created by using the typical C-RFA protocol. Upon completion needle will be removed. Following ablation, 0.5 mL of 0.5% bupivacaine will be injected at the site of the ablated neuroma to provide post procedure analgesia.
Overall Study STARTED	8
Overall Study Withdrew to Have Phenol Ablation	1
Overall Study Withdrew to Have Targeted Muscle Reinnervation Therapy	1
Overall Study COMPLETED	6
Overall Study NOT COMPLETED	2

Reasons for withdrawal

Reasons for withdrawal
Measure	Residual Limb Pain in Affected Amputated Limb Patient has residual limb pain in amputated limb and is scheduled to receive standard of care treatment of cooled radiofrequency ablation. Cooled Radiofrequency Ablation: RFA procedures will be performed with modification accounting for appropriate C-RFA technique. Participant will be positioned prone and skin prepped with chloroprep. Ultrasound probe will be placed on residual limb at a transverse angle in order to view the nerve and associated neuroma in long-axis. The probe will be advanced to the site of the stump neuroma. C-RFA electrode will be placed adjacent to neuroma. Needle will be connected via wire to a cooled radiofrequency generator. Motor and sensory testing will be performed to reproduce or exacerbate the RLP and / or PLP. At the site of the neuroma, 2 mL of local anesthetic will be injected through the needle. C-RFA lesions will be created by using the typical C-RFA protocol. Upon completion needle will be removed. Following ablation, 0.5 mL of 0.5% bupivacaine will be injected at the site of the ablated neuroma to provide post procedure analgesia.
Overall Study Withdrawal by Subject	2

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Residual Limb Pain in Affected Amputated Limb n=7 Participants Patient has residual limb pain in amputated limb and is scheduled to receive standard of care treatment of cooled radiofrequency ablation. Cooled Radiofrequency Ablation: RFA procedures will be performed with modification accounting for appropriate C-RFA technique. Participant will be positioned prone and skin prepped with chloroprep. Ultrasound probe will be placed on residual limb at a transverse angle in order to view the nerve and associated neuroma in long-axis. The probe will be advanced to the site of the stump neuroma. C-RFA electrode will be placed adjacent to neuroma. Needle will be connected via wire to a cooled radiofrequency generator. Motor and sensory testing will be performed to reproduce or exacerbate the RLP and / or PLP. At the site of the neuroma, 2 mL of local anesthetic will be injected through the needle. C-RFA lesions will be created by using the typical C-RFA protocol. Upon completion needle will be removed. Following ablation, 0.5 mL of 0.5% bupivacaine will be injected at the site of the ablated neuroma to provide post procedure analgesia.
Age, Categorical <=18 years	0 Participants n=7 Participants
Age, Categorical Between 18 and 65 years	4 Participants n=7 Participants
Age, Categorical >=65 years	3 Participants n=7 Participants
Age, Continuous	60.3 years n=7 Participants
Sex: Female, Male Female	1 Participants n=7 Participants
Sex: Female, Male Male	6 Participants n=7 Participants
Region of Enrollment United States	7 participants n=7 Participants
Height	166.2 Centimeters STANDARD_DEVIATION 16.17 • n=7 Participants
Weight	86.8 Kilograms STANDARD_DEVIATION 19.17 • n=7 Participants
Duration of Pain < 1 Year	1 Participants n=7 Participants
Duration of Pain 1 to 5 Years	4 Participants n=7 Participants
Duration of Pain > 5 Years	2 Participants n=7 Participants

PRIMARY outcome

Timeframe: 6 months

Outcome measures

Outcome measures
Measure	Residual Limb Pain in Affected Amputated Limb n=7 Participants Patient has residual limb pain in amputated limb and is scheduled to receive standard of care treatment of cooled radiofrequency ablation. Cooled Radiofrequency Ablation: RFA procedures will be performed with modification accounting for appropriate C-RFA technique. Participant will be positioned prone and skin prepped with chloroprep. Ultrasound probe will be placed on residual limb at a transverse angle in order to view the nerve and associated neuroma in long-axis. The probe will be advanced to the site of the stump neuroma. C-RFA electrode will be placed adjacent to neuroma. Needle will be connected via wire to a cooled radiofrequency generator. Motor and sensory testing will be performed to reproduce or exacerbate the RLP and / or PLP. At the site of the neuroma, 2 mL of local anesthetic will be injected through the needle. C-RFA lesions will be created by using the typical C-RFA protocol. Upon completion needle will be removed. Following ablation, 0.5 mL of 0.5% bupivacaine will be injected at the site of the ablated neuroma to provide post procedure analgesia.
Numeric Rating Scale (NRS) for Pain at 6 Months	4 Participants

SECONDARY outcome

Timeframe: 1, 3, 6, and 12 months

Population: Of the 7 participants included in the analyses, one participant withdrew from the study after outcome data were collected at 6-month follow-up to pursue alternative treatment.

Patients rated their residual limb pain intensity at baseline and the designated follow-up timepoints using an 11-point Numeric Rating Scale (NRS) ranging from 0 to 10, with 0 representing "no pain at all" and 10 representing "the worst pain imaginable". Change scores were calculated by subtracting follow-up scores from baseline scores. Median change scores and their interquartile ranges are reported here. Positive median change scores indicate pain improvement from baseline, with greater values corresponding to greater pain relief. Similarly, negative change scores indicate worsening pain from baseline.

Outcome measures

Outcome measures
Measure	Residual Limb Pain in Affected Amputated Limb n=7 Participants Patient has residual limb pain in amputated limb and is scheduled to receive standard of care treatment of cooled radiofrequency ablation. Cooled Radiofrequency Ablation: RFA procedures will be performed with modification accounting for appropriate C-RFA technique. Participant will be positioned prone and skin prepped with chloroprep. Ultrasound probe will be placed on residual limb at a transverse angle in order to view the nerve and associated neuroma in long-axis. The probe will be advanced to the site of the stump neuroma. C-RFA electrode will be placed adjacent to neuroma. Needle will be connected via wire to a cooled radiofrequency generator. Motor and sensory testing will be performed to reproduce or exacerbate the RLP and / or PLP. At the site of the neuroma, 2 mL of local anesthetic will be injected through the needle. C-RFA lesions will be created by using the typical C-RFA protocol. Upon completion needle will be removed. Following ablation, 0.5 mL of 0.5% bupivacaine will be injected at the site of the ablated neuroma to provide post procedure analgesia.
Median Change in Numeric Rating Scale (NRS) Scores for Pain 1 month	1.0 units on a scale Interval 0.5 to 3.0
Median Change in Numeric Rating Scale (NRS) Scores for Pain 3 months	2.0 units on a scale Interval 1.5 to 2.5
Median Change in Numeric Rating Scale (NRS) Scores for Pain 6 months	1.0 units on a scale Interval -1.5 to 3.0
Median Change in Numeric Rating Scale (NRS) Scores for Pain 12 months	3.0 units on a scale Interval 1.3 to 4.0

SECONDARY outcome

Timeframe: 1, 3, 6 and 12 Months

Population: Of the 7 participants included in the analyses, one participant withdrew from the study after outcome data were collected at 6-month follow-up to pursue alternative treatment.

The Medication Quantification Scale (MQS) is calculated using a pain-related medication detriment score based on drug class, which ranges from 1.1 to 4.5, and multiplying it by a usage score: 1 = subtherapeutic or occasional dose/2 = lower 50% of a therapeutic dose/ 3 = upper 50% of a therapeutic dose/ 4 = supratherapeutic dose. The higher the score, the more pain-related medication the participant takes to control their pain. The resulting score is useful in research for tracking individual or group pain medication use over time.

Outcome measures

Outcome measures
Measure	Residual Limb Pain in Affected Amputated Limb n=7 Participants Patient has residual limb pain in amputated limb and is scheduled to receive standard of care treatment of cooled radiofrequency ablation. Cooled Radiofrequency Ablation: RFA procedures will be performed with modification accounting for appropriate C-RFA technique. Participant will be positioned prone and skin prepped with chloroprep. Ultrasound probe will be placed on residual limb at a transverse angle in order to view the nerve and associated neuroma in long-axis. The probe will be advanced to the site of the stump neuroma. C-RFA electrode will be placed adjacent to neuroma. Needle will be connected via wire to a cooled radiofrequency generator. Motor and sensory testing will be performed to reproduce or exacerbate the RLP and / or PLP. At the site of the neuroma, 2 mL of local anesthetic will be injected through the needle. C-RFA lesions will be created by using the typical C-RFA protocol. Upon completion needle will be removed. Following ablation, 0.5 mL of 0.5% bupivacaine will be injected at the site of the ablated neuroma to provide post procedure analgesia.
Medication Quantification Scale III Mean Score 1 Month	8.3 Score on a scale Interval 6.1 to 10.0
Medication Quantification Scale III Mean Score 3 Months	6.9 Score on a scale Interval 4.6 to 8.1
Medication Quantification Scale III Mean Score 6 Months	7.1 Score on a scale Interval 3.6 to 8.5
Medication Quantification Scale III Mean Score 12 Months	7.1 Score on a scale Interval 2.4 to 9.7

SECONDARY outcome

Timeframe: 1, 3, 6, and 12 months

Population: Of the 7 participants included in the analyses, one participant withdrew from the study after outcome data were collected at 6-month follow-up to pursue alternative treatment.

Patient Global Impression of Change is a scale which measures participant reported satisfaction after an intervention. The outcome was measured as the percent of patients reporting a PGIC score of 6-7 (indicating "much improved" and "very much improved").

Outcome measures

Outcome measures
Measure	Residual Limb Pain in Affected Amputated Limb n=7 Participants Patient has residual limb pain in amputated limb and is scheduled to receive standard of care treatment of cooled radiofrequency ablation. Cooled Radiofrequency Ablation: RFA procedures will be performed with modification accounting for appropriate C-RFA technique. Participant will be positioned prone and skin prepped with chloroprep. Ultrasound probe will be placed on residual limb at a transverse angle in order to view the nerve and associated neuroma in long-axis. The probe will be advanced to the site of the stump neuroma. C-RFA electrode will be placed adjacent to neuroma. Needle will be connected via wire to a cooled radiofrequency generator. Motor and sensory testing will be performed to reproduce or exacerbate the RLP and / or PLP. At the site of the neuroma, 2 mL of local anesthetic will be injected through the needle. C-RFA lesions will be created by using the typical C-RFA protocol. Upon completion needle will be removed. Following ablation, 0.5 mL of 0.5% bupivacaine will be injected at the site of the ablated neuroma to provide post procedure analgesia.
Proportion of Patients With a ≥6 Score on Patient Global Impression of Change (PGIC) 1 month	3 Participants
Proportion of Patients With a ≥6 Score on Patient Global Impression of Change (PGIC) 3 months	3 Participants
Proportion of Patients With a ≥6 Score on Patient Global Impression of Change (PGIC) 6 months	1 Participants
Proportion of Patients With a ≥6 Score on Patient Global Impression of Change (PGIC) 12 months	1 Participants

Adverse Events

Residual Limb Pain in Affected Amputated Limb

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

Zachary McCormick, MD

University of Utah Orthopaedic Center/ Physical Medicine & Rehabilitation

Phone: 801-587-1493

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place