Altius Peripheral Nerve Stimulation in Amputees After TMR/RPNI

A Single-Center, Prospective, Within-Subject Study of Altius® Direct Electrical Nerve Stimulation System in Lower Extremity Amputees With Persistent Pain After Targeted Muscle Reinnervation (TMR) and/or Regenerative Peripheral Nerve Interface (RPNI)

This is a single-center, prospective, within-subject study. This study seeks to enroll a total of 32 prospective subjects who will undergo surgical implantation of the FDA-approved Altius® system. Subjects will be followed longitudinally and will complete a series of patient-reported outcome measure questionnaires, a study intake questionnaire which assesses demographics, amputation and prosthesis history, and medical/medication history.

Study Overview

• Status: Not yet recruiting
• Conditions: Amputation; Lower Extremity; Pain, Persistent Postsurgical
• Intervention / Treatment: Device: Surgical Implantation

• Study Type: Interventional
• Enrollment (Estimated): 32
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Anne Genzelev; Phone Number: 617-835-8018; Email: Anne.genzelev@nyulangone.org
• Study Contact Backup: Name: Jacques Hacquebord, MD; Phone Number: 646-413-9861; Email: Jacques.Hacquebord@nyulangone.org

Study Locations

• United States
  • New York
    • New York, New York, United States, 10016
      • NYU Langone Health

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Adults (≥18 years old)
• Lower extremity amputees with prior TMR, RPNI at least 9 months prior to enrollment, or similar nerve-targeted surgery who have persistent neuropathic pain
• Persistent chronic/intractable neuropathic pain that is moderate to severe (VAS ≥4)
• 50% or greater pain reduction after receiving SOC ultrasound-guided lidocaine injection
• Able and willing to provide consent

Exclusion Criteria:

• Non-LE amputees
• LE amputees without moderate to significant pain
• LE amputees who have not undergone TMR, RPNI, or similar nerve targeted surgeries, amputees who have undergone these surgeries less than 9 months prior to enrollment, or amputees who have undergone these surgeries and do not have persistent pain

• Patients with contraindications to implant surgery

  • Presence of any active implantable device (e.g, pacemaker, implantable cardioverter-defibrillator, other neurostimulator or drug pump)
  • Anticipated need for MRI or diathermy after implantation
  • Uncontrolled diabetes, defined as HbA1c > 8.0 at screening due to increased risk of surgical complications and delayed wound healing
  • Pregnant, breastfeeding, intending pregnancy during the study period, or unwilling to use effective contraception
  • Suspected or known allergy to any component of the Altius system or to lidocaine used for the diagnostic lidocaine block.
  • Severe scarring, skin grafting, or other anatomic constraints over the planned implant site that would prevent safe placement of the cuff electrode(s), lead(s), or IPG
  • Spasticity of the residual limb preventing comfortable full range of motion, which may interfere with stability or comfort of the implanted leads.
  • Other significant pain syndromes that, in the investigator's judgment, would likely confound assessment of phantom limb or residual limb neuropathic pain outcomes.
  • Active substance abuse; severe psychiatric illness that may interfere with study participation (e.g., recent psychiatric hospitalization or other condition that impairs ability to comply with study procedures); or inability to comply with follow up visits or operation of the Altius Direct Electrical Nerve Stimulation System.
  • Uncontrolled infection at the amputation site or bleeding disorders
  • Unable to operate the Altius® Direct Electrical Nerve Stimulation System
  • Unsuitable for the Altius implant surgery
• Unable to participate in follow-ups according to study schedule (1 month, 3 months, and 6 months post-op)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Adult Lower Extremity (LE) Amputees; Adult LE amputees with chronic/intractable pain despite previous TMR and/or RPNI surgery.	Device: Surgical Implantation; The Altius system will be surgically implanted into the patient on one occasion. The Altius system is then used on an 'as needed' basis by patient.; Other Names: Altius® Direct Electrical Nerve Stimulation System

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Hours Per Day of Prosthesis Use	Participants provide their average hours per day of prosthesis use over the past 7 days.	Baseline, Month 1, Month 3, Month 6
Change in Days Per Week of Prosthesis Use	Participants provide their average number of days of prosthesis use over the past 7 days.	Baseline, Month 1, Month 3, Month 6
Change in Prosthesis Function Level	Participants rate their current level of function with their prosthesis on a scale from 1 (extremely low) to 10 (extremely high).	Baseline, Month 1, Month 3, Month 6
Change in Prosthesis Satisfaction Level	Participants rate their current level of satisfaction with their prosthesis on a scale from 1 (extremely dissatisfied) to 10 (extremely satisfied).	Baseline, Month 1, Month 3, Month 6
Change in Locomotor Capabilities Index (LCI-5) Score	14-item assessment of locomotor capabilities; each item is rated on a 5-point scale from 0 to 4; the total score is the sum of responses and ranges from 0-56; higher scores indicate greater locomotor capabilities.	Baseline, Month 1, Month 3, Month 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Patient Health Questionnaire-9 (PHQ-9) Score	9-item assessment of depressive symptoms; each item is rated on a scale from 0-3; the total score is the sum of responses and ranges from 0-27; higher scores indicate greater severity of depressive symptoms.	Baseline, Month 1, Month 3, Month 6
Change in Visual Analogue Score (VAS) - Residual Pain	Residual pain will be rated on a VAS scale ranging from 0 (no pain) to 10 (worst possible pain).	Baseline, Month 1, Month 3, Month 6
Change in Visual Analogue Score (VAS) - Phantom Pain	Phantom pain will be rated on a VAS scale ranging from 0 (no pain) to 10 (worst possible pain).	Baseline, Month 1, Month 3, Month 6
Change in PROMIS Pain Intensity Short Form 8a Score	The Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Intensity Short Form 8a is an 8-item assessment of pain interference in daily life. Each item is rated on a scale from 1 (not at all) to 5 (very much). The raw score is the sum of responses; the raw score is converted to a standardized score ranging from 0-100 with a mean of 50; higher scores indicate more pain interference.	Baseline, Month 1, Month 3, Month 6
Number of Participants Taking Opioids/Narcotics for Pain		Baseline, Month 1, Month 3, Month 6
Number of Participants Taking Medication for Nerve Pain		Baseline, Month 1, Month 3, Month 6
Number of Participants Taking Nonsteroidal Anti-inflammatory Drugs (NSAIDs) for Pain		Baseline, Month 1, Month 3, Month 6

Collaborators and Investigators

• Sponsor: NYU Langone Health
• Investigators: Principal Investigator: Jacques Hacquebord, MD, NYU Langone Health

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): July 1, 2028
• Study Completion (Estimated): July 1, 2028

Study Registration Dates

• First Submitted: April 30, 2026
• First Submitted That Met QC Criteria: April 30, 2026
• First Posted (Actual): May 6, 2026

Study Record Updates

• Last Update Posted (Actual): May 6, 2026
• Last Update Submitted That Met QC Criteria: April 30, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative
• Other Study ID Numbers: 26-00331

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No