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Somatotopic Configuration of Distal Residual Limb Tissues in Lower Extremity Amputations

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ClinicalTrials.gov Identifier: NCT03374319
Recruitment Status : Recruiting
First Posted : December 15, 2017
Last Update Posted : May 4, 2021
Massachusetts Institute of Technology
University of Michigan
Northwestern University
Information provided by (Responsible Party):
Matthew Carty, Brigham and Women's Hospital

Brief Summary:

The hypothesis of this research protocol is that we will be able to redesign the manner in which lower limb amputations are performed so as to include biological actuators that will enable the successful employment of next generation lower extremity prostheses. The specific aims of the project are as follows:

  1. To define a standardized approach to the performance of a novel operative procedure for both below knee (BKA) and above knee (AKA) amputations
  2. To measure the degree of volitional motor activation and excursion achievable in the residual limb constructs, and to determine the optimal configuration and design of such constructs
  3. To describe the extent of proprioceptive and other sensory feedback achievable through the employment of these modified surgical techniques
  4. To validate the functional and somatosensory superiority of the proposed amputation technique over standard approaches to BKA and AKA
  5. To develop a modified acute postoperative rehabilitation strategy suited to this new surgical approach

Condition or disease Intervention/treatment Phase
Amputation Procedure: Modified amputation procedure Procedure: Amputation procedure with TMR and/or RPNI construction Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 40 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Somatotopic Configuration of Distal Residual Limb Tissues in Lower Extremity Amputations
Actual Study Start Date : September 15, 2017
Estimated Primary Completion Date : September 15, 2021
Estimated Study Completion Date : September 15, 2021

Arm Intervention/treatment
Experimental: Intervention group
Modified amputation procedure
Procedure: Modified amputation procedure
A stair-step (BKA) or fishmouth (AKA) incision will be made. Tibial and fibular or femoral osteotomies will be performed. Segments of the tibialis anterior (TA), peroneus longus (PL), lateral gastrocnemius (LG) and tibialis posterior (TP) muscles will be isolated, as well as the quadriceps (Q) and hamstring (H) groups in the AKA model; if it is not possible to preserve native innervation to these muscles, functional motor units will be constructed from muscle coapted to the appropriate motor nerve endings. The distal tibial and peroneal nerves will be redirected to skin patches in the distal or proximal thigh. Coaptation of the TA/LG, PL/TP and Q/H muscles will then be performed to promote dynamic coupling of these agonist/antagonist pairs. The skin envelope will then be closed in layers over percutaneous drains.
Other Names:
  • Ewing
  • AMI
  • agonist-antagonist myoneural interface

Active Comparator: Control group
Amputation procedure with TMR and/or RPNI construction
Procedure: Amputation procedure with TMR and/or RPNI construction
Amputation is performed via standard techniques at either the BKA or AKA level, incorporating either targeted muscle reinnervation or the construction of regenerative peripheral nerve interfaces, or both. No construction of agonist-antagonist muscle pairs will be performed.
Other Names:
  • targeted muscle reinnervation
  • regenerative peripheral nerve interface

Primary Outcome Measures :
  1. Motor Unit Innervation [ Time Frame: 0-48 months ]
    Intact volitional activation of motor constructs, as assessed by electromyographic evidence of activation (muscle potentials measured in mV)

  2. Motor Unit Excursion [ Time Frame: 0-48 months ]
    Intact volitional activation of motor constructs with measurable excursion, as assessed by ultrasound (excursion measured in mm)

  3. Proprioception Recovery [ Time Frame: 0-48 months ]
    Manifestation of functional proprioception with motor unit activation, as evidenced by spatial limb position testing using a modified lower limb prosthesis (accurate limb positioning relative to target measured in mm)

Secondary Outcome Measures :
  1. Infection Rate [ Time Frame: 0-48 months ]
    Postoperative infection rate

  2. Delayed Wound Healing Rate [ Time Frame: 0-48 months ]
    Postoperative delayed wound healing rate

  3. Operative Revision Rate [ Time Frame: 0-48 months ]
    Subsequent rate of reoperation

  4. Seroma Rate [ Time Frame: 0-48 months ]
    Postoperative seroma rate

  5. Deep Vein Thrombosis Rate [ Time Frame: 0-48 months ]
    Postoperative deep vein thrombosis rate

  6. 30-Day Mortality Rate [ Time Frame: 0-48 months ]
    Postoperative 30-day mortality rate

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Males or females between the ages of 18 and 65
  • Candidates for elective unilateral or bilateral lower extremity amputation at either the above knee or below knee level due to traumatic injury, congenital limb deformities or progressive arthritis
  • Must demonstrate sufficiently sound health to undergo the operative procedure, including adequate cardiopulmonary stability to undergo general anesthesia (specifically, American Society of Anesthesiology Class I or II)
  • Must have intact inherent wound healing capacity
  • Must demonstrate adequate communication skills to convey the status of their sensorimotor recovery throughout the postoperative phase,
  • Must exhibit proper level of motivation to comply with postoperative follow up requirements.
  • Must be willing to also consent to protocol #1801183130 at Massachusetts Institute of Technology (approved by the Committee on the Use of Humans as Experimental Subjects) as some outcome measures will be assessed under this affiliated study

Exclusion Criteria:

  • Patients beyond the stated age restrictions
  • Those with severe illness rendering them unable to undergo the operative procedure safely (e.g., unresolved sepsis or cardiopulmonary instability manifest as documented coronary artery disease and/or chronic obstructive pulmonary disease).
  • Patients with impairment in inherent wound healing pathways, such as those with primary connective tissue disorders or those on chronic steroid therapy
  • Patients with extensive peripheral neuropathies (diabetic or otherwise) that would potentially inhibit appropriate reinnervation of the surgical constructs
  • Active smokers; those patients willing to undergo tobacco cessation will need to be completely abstinent from tobacco use for at least 6 weeks preoperatively
  • Patients who are unable to provide informed consent and those with a demonstrated history of poor compliance
  • Pregnant women will not be considered due to the potential risks of general anesthesia.

Patients will not be excluded from participation in the study on the grounds of minority status, religious status, race or gender. Non-English speaking patients will not be excluded from the study; interpreters will be made available to them for translation of both verbal interactions and written documents.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03374319

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Contact: Matthew J Carty, MD 6179834555 mcarty@partners.org

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United States, Illinois
Northwestern University Not yet recruiting
Evanston, Illinois, United States, 60208
Contact: Greg Dumanian, MD    312-695-6022    gdumania@nm.org   
Principal Investigator: Greg Dumanian, MD         
Sub-Investigator: Jason Ko, MD         
United States, Massachusetts
Brigham & Women's Hospital Recruiting
Boston, Massachusetts, United States, 02114
Contact: Matthew J Carty, MD    617-983-4555    mcarty@partners.org   
Principal Investigator: Matthew J Carty, MD         
Massachusetts Institute of Technology Media Lab Recruiting
Cambridge, Massachusetts, United States, 02139
Contact: Hugh Herr, PhD    617-314-3661    hherr@media.mit.edu   
Principal Investigator: Hugh Herr, PhD         
United States, Michigan
University of Michigan Recruiting
Ann Arbor, Michigan, United States, 48109
Contact: Paul Cederna, MD    734-998-6022    cederna@med.umich.edu   
Principal Investigator: Paul Cederna, MD         
Sponsors and Collaborators
Brigham and Women's Hospital
Massachusetts Institute of Technology
University of Michigan
Northwestern University
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Principal Investigator: Matthew J Carty, MD Brigham and Women's Hospital

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Matthew Carty, Staff Surgeon, Brigham and Women's Hospital
ClinicalTrials.gov Identifier: NCT03374319    
Other Study ID Numbers: 2014p001379
CDMRP-160165 ( Other Grant/Funding Number: Department of Defense )
First Posted: December 15, 2017    Key Record Dates
Last Update Posted: May 4, 2021
Last Verified: April 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Plan Description: No plan for individual participant data sharing

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No