Short-term Implanted Electrodes Following Regenerative Peripheral Nerve Surgery for Improving Prosthetic Limb Control Signals

NCT03260400 | Recruiting FDA Device

• 2 other identifiers: HUM001248395R01NS105132-05
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

The device, a bipolar percutaneous intramuscular electromyography electrode, is intended for use in upper-limb amputation patients who have received the regenerative peripheral nerve interface surgical procedure, in order to enable the use of advanced prosthetic arms and hands.

Conditions

Amputation Neuroma; Amputation

Keywords

RPNI; Regenerative Peripheral Nerve Interface

Outcome Measures

Primary Outcomes (5)

• Change in Pain Level as measured by SF-36

  Pain will be assessed using the SF-36 survey instrument, to be filled out by the participant before and after each surgical procedure performed and at a minimum of once per month while electrodes remain implanted. Two questions related to pain with a score closer to 0 means a pain increase

  Baseline and monthly for up to 7 years postoperatively

• Change in Pain Level as measured by LANSS survey

  Pain will be assessed using the LANSS survey instrument, to be filled out by the participant before and after each surgical procedure performed and at a minimum of once per month while electrodes remain implanted. A score greater than 12 indicates neuropathic pain.

  Baseline and monthly for up to 7 years postoperatively

• Change in Pain Level as measured by Phantom Limb Questionnaire

  Phantom pain will be assessed using the Phantom Limb Questionnaire, to be filled out by the participant before and after each surgical procedure performed and at a minimum of once per month while electrodes remain implanted. This 9-item instrument measures phantom pain on a scale of 0-4, where 0-no pain at all and 4=very severe pain.

  Baseline and monthly for up to 7 years postoperatively

• RPNI tissue degeneration measured by pain scores

  RPNI tissue degeneration will be assessed by changes in pain scores (see above) and measurements of recording efficacy. Recording efficacy will be assessed using two signal quality measures: 1. Peak-to-peak signal amplitude during maximum voluntary contraction 2. Signal-to-noise ratio during maximum voluntary contraction

  Baseline and once per month after surgery following a 3-month postoperative recovery period, while electrodes remain implanted.

• RPNI electrode migration assessed by changes recording in efficacy and ultrasound

  Electrode migration outside of the implanted RPNI graft or muscle will be assessed by changes in recording efficacy, as described above, and by ultrasound examination as necessary. Electrode extrusion and implantation complications will be assessed by adverse events reported by both the participant and the study physicians. At each study visit, the participant will be asked to report any issues, and will have a basic examination of the affected limb performed by study physicians and/or trained staff.

  Baseline and once per month after surgery following a 3-month postoperative recovery period, while electrodes remain implanted.

Secondary Outcomes (2)

• EMG signal quality from RPNI grafts

  Baseline and monthly for up to 7 years postoperatively

• Stimulation Threshold of RPNI grafts

  Baseline and monthly for up to 7 years postoperatively

Study Arms (2)

New Grafts

EXPERIMENTAL

In this arm, participants will have an initial surgery to place partial muscle grafts on the amputated nerves. After a healing period, the participant will have a shorter surgical procedure to implant the electrodes onto the muscle grafts and in residual muscles. After another healing period, experiments with prosthetic control and sensory feedback will begin.

Device: a bipolar percutaneous intramuscular electromyography electrode

Existing Grafts

EXPERIMENTAL

In this arm, participants have already had partial muscle grafts placed on the amputated nerves to control neuroma growth. The participant will have a short surgical procedure to implant the electrodes onto the muscle grafts and in residual muscles. After a healing period, experiments with prosthetic control and sensory feedback will begin.

Device: a bipolar percutaneous intramuscular electromyography electrode

Interventions

a bipolar percutaneous intramuscular electromyography electrode DEVICE

The device, a bipolar percutaneous intramuscular electromyography electrode, is intended for use in upper-limb amputation patients who have received the regenerative peripheral nerve interface surgical procedure, in order to enable the use of advanced prosthetic arms and hands.

Existing Grafts; New Grafts

Eligibility Criteria

• Age: 22 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Participants must be 22 years of age or older.
• Participants must have previously undergone an upper limb amputation proximal to the wrist.
• Participants must be in good health and American Society of Anesthesiologists (ASA) Class I or II (low surgical risk).
• Participants must have reliable transportation.
• Participants must be able to attend at minimum 2 visits per month while electrodes remain implanted.
• Participants must be at least 6 months post-amputation.

You may not qualify if:

• Participants may not be suffering from any severe pain syndrome including complex regional pain syndrome or severe phantom pain. All of these conditions would suggest pathological activity of the nerve and would exclude the participant from participation.
• Participants must not be suffering from any untreated mental health disorders and if they have any DSM-5 diagnoses, they must receive approval to participate from their mental health professional.
• Participants must not have any medical conditions that, in the opinion of the Principal Investigator, would place them at high risk for a surgical procedure including recent myocardial infarction, cerebrovascular accidents, deep venous thrombosis, pulmonary embolus, uncontrolled diabetes, or end stage renal disease.
• Participants must not have used tobacco for at least one month prior to enrollment in the study.
• Participants must agree to not use tobacco for the duration of the study.
• Participants cannot have sustained bilateral upper extremity amputation.
• Participants cannot be pregnant.
• Participants must not have other indwelling electronic implants like pacemakers, implantable cardioverter defibrillators, implantable neurostimulators, body worn insulin pumps, or body worn patient monitoring devices.
• Participants must not have severe peripheral vascular occlusive disease, venous hypertension of the extremity, or severe lymphedema of the extremity.
• Participants must not have an autoimmune condition which is not well controlled by medication.
• Participants will not be considered for enrollment in Primary Upper Limb Amputation with RPNI Grafts and Electrode Implantation if their amputation is a traumatic injury or cancer related

Sponsors & Collaborators

• University of Michigan: lead
• National Institute of Neurological Disorders and Stroke (NINDS): collaborator

Study Sites (1)

University of Michigan

Ann Arbor, Michigan, 48109, United States

RECRUITING

Related Publications (1)

• Lee C, Vaskov AK, Gonzalez MA, Vu PP, Davis AJ, Cederna PS, Chestek CA, Gates DH. Use of regenerative peripheral nerve interfaces and intramuscular electrodes to improve prosthetic grasp selection: a case study. J Neural Eng. 2022 Nov 14;19(6):10.1088/1741-2552/ac9e1c. doi: 10.1088/1741-2552/ac9e1c.

  PMID: 36317254 DERIVED

Study Officials

• Paul Cederna, M.D.

  University of Michigan

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Paul Cederna, M.D.

CONTACT

734-936-5885; cederna@umich.edu

Jenni Hamill, MPH

CONTACT

734-936-5885; jenberry@med.umich.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: DEVICE FEASIBILITY
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Robert Oneal Professor and Chief of Plastic Surgery; Professor, Biomedical Engineering

Study Record Dates

• First Submitted: July 25, 2017
• First Posted: August 24, 2017
• Study Start: December 11, 2017
• Primary Completion (Estimated): May 5, 2029
• Study Completion (Estimated): May 5, 2029
• Last Updated: August 26, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)