Results of Nerve Surgery to Treat PostAmputation Pain (TreatPAP)

May 18, 2026 updated by: jlgroen, Leiden University Medical Center

Results of Nerve Surgery to Treat PostAmputation Pain (TreatPAP): a Prospective Study

Rationale: Postamputation pain (PAP) is frequently seen after amputations and is a severe lifelong disabling condition affecting quality of life (QoL). Different nerve surgical techniques are available to treat PAP if non-surgical treatment options are not sufficient. Multiple techniques have been described for treatment of symptomatic neuromas with varying results. Techniques described include traction neurectomy with/without implantation, nerve grafting, nerve capping, regenerative peripheral nerve interface, and targeted muscle reinnervation (TMR). In the Leiden University Medical Center (LUMC), the most common techniques to treat painful neuromas include TMR and fascicular split (FS). TMR involves coaptating the transected mixed nerve to functional motor nerves, showing promising results in recent studies. FS is a technique closely related to neurectomy with implantation in a functional muscle. The difference is that with FS, the nerve is split into fascicles before implantation to allow for better distribution of nerve fibers. These techniques have not yet been compared. In this study, the investigators will compare both these techniques in a prospective setting for the treatment of PAP. The hypothesis is, that after 12 months, pain will be diminished and QoL will be increased in all patients versus the pre-operative status. There will be little to no difference in outcome between the surgical techniques used.

Objective: To evaluate limb pain in patients with intractable postamputation pain (residual limb pain and phantom limb pain) one year after nerve embedding surgery following the standardized workup of the LUMC.

Study design: Prospective study Study population: Patients 18 years of age or older, with a history of more than 6 months of intractable postamputation neuropathic limb pain, with no history of previous surgical intervention for pain treatment, referred to the Leiden Nerve Center.

Main study parameters/endpoints: The mean difference in pain scores for phantom limb pain and residual limb pain one year postoperatively. An average pain score from the past 7 days is used for PLP and RLP individually, on the 11-point (0-10) numerical rating scale (NRS). Additionally, the Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Behavior and Interference Questionnaire Short Forms (7a and 8a, respectively) are used one year postoperatively.

Nature and extent of the burden and risks associated with participation, benefit, and group relatedness: Both techniques are currently used in the Leiden University Medical Center (LUMC) and considered standard of care. The decision to perform either technique is solely dependent on the personal preference of the treating nerve surgeon. The results of this trial will improve the understanding of the treatment effect of both surgical techniques with a minimal patient burden. Participation requires patients to complete 3-4 non-invasive questionnaires about pain, quality of life, depression and anxiety, and mobility over a period of 2 years. The pre-operative (if applicable) and 12-month postoperative questionnaire will each take approximately 15 minutes to complete. The other two questionnaires at 18 and 24 months postoperative will take approximately 3-4 minutes to complete. Additionally, participants will fill out a daily questionnaire consisting of one to three questions about pain for 7 consecutive days at 12 months.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Postamputation pain (PAP) is a common sequela after major lower limb amputation, with an estimated incidence of 61%. PAP can be divided into two major categories: phantom limb pain (PLP) and residual limb pain (RLP, 'stump pain'). Both RLP and PLP are predominantly driven by the cut nerve endings during the amputation, that form terminal-neuromas. PAP is known to compromise prosthetic rehabilitation and profoundly diminishes the quality of life after amputation. When PAP develops, it is extremely difficult to treat. When non-surgical treatment fails, or side effects of medication dominate patients' lives, surgery for PAP is occasionally undertaken. Nerve surgical techniques that are then applied differ widely and lack any solid scientific base. In general, secondary surgery for PAP includes resection of the neuroma and transposition of the freshened nerve into a more favorable environment, such as muscle, bone, vessels, or fat. This nerve implantation technique has been described since 1918 to treat painful neuromas, showing good results ranging from 64 to 82% of pain relief. Based on the vast experience gained over a 25-year period in the Leiden Nerve Center in treating painful neuromas, an adaptation of the nerve implantation method was developed called the Fascicular Split (FS) technique to treat PAP. In the FS technique, after transecting the neuroma, the nerve is first split into multiple fascicles before implanting the nerve in the muscle. This allows for better distribution of the nerve in the muscle, resulting in less neuroma formation. The strength of FS is its relative simplicity, which is crucial for the wider implementation in routine care. Promising results were observed applying this technique in a small series (n=8) of patients with PAP yielding a long-lasting, life-changing effect in all but one patient. In some cases, FS was performed years after the initial amputation and after previous failed neuroma surgeries. Other nerve handling techniques to treat symptomatic neuroma include centro-central neurorrhaphy, End-to-Side neurorrhaphy, Graft to Nowhere, Targeted Muscle Reinnervation (TMR), and Regenerative Peripheral Nerve Interface. TMR is, after simply embedding the nerve in healthy tissue, the best studied and most promising technique to treat PAP. Several cohort studies and a recent randomized trial in secondary surgery for PAP show that a nerve surgical technique called Targeted Muscle Reinnervation (TMR) is effective in treating PAP. However, the main disadvantage of TMR is that it is a time-consuming procedure.

To date, there are no studies that compare both techniques for the treatment of PAP. The investigators believe that the treatment FS yields similar results to TMR. Moreover, in terms of clinical applicability, the FS technique is easier to learn, does not require extensive nerve surgical skills, and does not take much time to perform.

Few papers have been published on TMR as a treatment for postamputation pain. Despite issues with the validity of the articles, results of PLP and RLP were consistently in favor of TMR as a technique regarding all outcome measures, including intensity and interference with daily activities. FS, although not mentioned in the literature, has many similarities with nerve implantation, which showed similarly good results for the treatment of painful neuromas. However, there have been no studies to date that directly compare the two techniques.

PAP is a lifelong disabling condition profoundly affecting quality of life. Nerve embedding surgical techniques (simple, FS, and TMR) have proven to be effective to treat postamputation pain. Preliminary results show that simple embedding, TMR, and FS are potentially good techniques to treat invalidating PAP. However, no comparative studies have been performed.

The investigators hypothesize that FS will show equally good results compared to TMR in the surgical treatment of intractable PAP, reducing pain, and improving quality-of-life (QoL) and mobility.

The investigators propose a prospective observational cohort study evaluating outcomes after various nerve embedding techniques following a standardized selection protocol in patients with intractable post-amputation pain after a major limb amputation.

Study Type

Observational

Enrollment (Estimated)

98

Contacts and Locations

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

Study Contact

Study Locations

  • Netherlands
    • South Holland
      • Leiden, South Holland, Netherlands, 2333 ZA
        • Recruiting
        • Leiden University 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

Sampling Method

Non-Probability Sample

Study Population

Patients with intractable postamputation pain after a major extremity amputation (trans humeral, elbow disarticulation, forearm, transfemoral, knee disarticulation, and transtibial) undergoing surgical postamputation pain treatment in our center.

Description

Inclusion Criteria:

  • Age older than or equal to 18 years
  • Intractable postamputation pain

Exclusion Criteria:

  • Cognitive impairment or delirium at the time of inclusion
  • Having received previous radiotherapy on the affected limb
  • Patients who are unable to comprehend the informed consent form or the questionnaires used in the current study
  • Unfit for general anesthesia

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Control: Targeted Muscle Reinnervation (TMR)
Patients with a symptomatic neuroma requiring surgical intervention
Procedure: Targeted Muscle Reinnervation

Targeted Muscle Reinnervation surgical technique

  1. Painful nerve is identified and the neuroma is resected.
  2. A nerve stimulator is used to identify functional motor nerve branches. Near the point where the motor branch enters the muscle, the motor nerve branch is transected
  3. End-to-end nerve coaptation is performed between the amputated nerve and the transected motor nerve branch.
Intervention: Fascicular split
Patients with a symptomatic neuroma requiring surgical intervention
Procedure: Fascicular split

Fasicular split surgical technique:

  1. Painful nerve is identified and the neuroma is resected.
  2. Split the nerve into its constituent multiple nerve fascicles
  3. Create a deep muscle pocket for each individual fascicle
  4. Plant each fascicle into a separate muscle compartment and fixate the fascicle in place with tissue glue.
Other Names:
  • nerve embedding

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Phantom limb pain measured on the 11-point (0-10) numeric rating scale.
Time Frame: 1 year postoperatively
A primary endpoint is the mean phantom limb pain experience one year postoperatively. This will be measured on the 11-point (0-10) numeric rating scale over 7 consecutive days. A higher score indicates worse pain.
1 year postoperatively
Residual limb pain measured on the 11-point numeric rating scale
Time Frame: 1 year postoperatively
A primary endpoint is the mean residual limb pain experience one year postoperatively. This will be measured on the 11-point (0-10) numeric rating scale over 7 consecutive days. A higher score indicates worse pain.
1 year postoperatively
PROMIS pain behavior short form 7a
Time Frame: 1 year postoperatively
PROMIS pain behavior short form 7a in Dutch-Flemish
1 year postoperatively
PROMIS pain interference short form 8a
Time Frame: 1 year postoperatively
PROMIS pain interference short form 8a in Dutch-Flemish
1 year postoperatively

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Phantom limb pain using the 11-point (0-10) numeric rating scale
Time Frame: From enrolment until 24 months post-operatively
From enrolment until 24 months post-operatively
Residual limb pain using the 11-point (0-10) numeric rating scale
Time Frame: From enrolment until 24 months postoperatively
From enrolment until 24 months postoperatively
PROMIS pain behavior 7a short form in Dutch-Flemish
Time Frame: From enrolment until 24 months postoperatively
From enrolment until 24 months postoperatively
PROMIS pain interference 8a short form in Dutch-Flemish
Time Frame: From enrolment until 24 months postoperatively
From enrolment until 24 months postoperatively
Quality of life (EQ-5D-5L)
Time Frame: From enrolment until 24 months postoperatively
From enrolment until 24 months postoperatively
Pain type using the ICAN localization map
Time Frame: From enrolment until 12 months postoperatively
From enrolment until 12 months postoperatively
Neuropathic pain using the PainDetect
Time Frame: From enrolment until 12 months postoperatively
From enrolment until 12 months postoperatively
Hospital anxiety and depression using the HADS
Time Frame: From enrolment until 12 months postoperatively
From enrolment until 12 months postoperatively
Perceived treatment effect using the GPE-DV
Time Frame: at 12 months postoperativley
at 12 months postoperativley
Prosthetic rehabilitation using the PLUS-M
Time Frame: From enrolment until 12 months postoperatively
From enrolment until 12 months postoperatively
Changes in sensory quality in the amputated stump using quantitative sensory testing (QST)
Time Frame: at enrolment until 12 months postoperative
at enrolment until 12 months postoperative
Quantified neuroma perfusion using near-infrared fluorescence using indocyanine green
Time Frame: Peri-operatively
Patients will receive near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) during the surgery. ICG is a fluorescent dye that binds to plasma proteins and emits light when excited by near-infrared wavelengths. After intravenous injection, the dye circulates rapidly, allowing surgeons to assess blood flow to tissue of interest. This method has very good safety profile and has been used extensively in gastro-intestinal, reconstructive, vascular and neurosurgery. This study aims to use quantified ICG NIR fluorescence imaging to evaluate perfusion patterns of symptomatic and asymptomatic neuromas after amputation.
Peri-operatively
Surgery duration
Time Frame: Perioperatively
in minutes
Perioperatively
Length of hospital stay
Time Frame: From the date of surgery to the date of discharge from the hospital, up to 1 year post surgery
Amount of days patients spent in hospital post surgery
From the date of surgery to the date of discharge from the hospital, up to 1 year post surgery
Adverse events
Time Frame: until 30 days postoperatively
i.e., infection, rebleed, with Clavien-Dindo scores
until 30 days postoperatively
Medication Quantification Scale
Time Frame: until 24 months postoperatively
Phantom limb pain, residual limb pain, the PROMIS pain behavior 7a short form, and the PROMIS interference 8a short form will be corrected for pain medication use, using the medication quantification scale. A higher score indicates more pain medication use.
until 24 months postoperatively

Collaborators and Investigators

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

Sponsor

Leiden University Medical Center

Investigators

  • Principal Investigator: Justus L. Groen, MD, PhD, Leiden University 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 (Actual)

August 14, 2025

Primary Completion (Estimated)

August 20, 2028

Study Completion (Estimated)

August 20, 2029

Study Registration Dates

First Submitted

September 15, 2025

First Submitted That Met QC Criteria

May 18, 2026

First Posted (Actual)

May 26, 2026

Study Record Updates

Last Update Posted (Actual)

May 26, 2026

Last Update Submitted That Met QC Criteria

May 18, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 25-3058

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Undecided

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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