Magnetic Bead Tracking System and eOPRA Implant System With Bionic Prosthesis for Transtibial Amputees

NCT06391697 | Active Not Recruiting DMC FDA Device

• 1 other identifier: 2024P00006
• Study Type: interventional
• Target: 7
• Locations: 1 country
• Sites: 2

Brief Summary

The e-OPRA Implant System, is a further development of the OPRA (Osseointegrated Prostheses for the Rehabilitation of Amputees) Implant System. The e-OPRA Implant system is an implant system for direct skeletal anchorage of amputation prostheses. The added feature in the e-OPRA Implant system, is a bidirectional interface into the human body that allows permanent and reliable communication using implanted electrodes. These electrodes will provide long-term stable bioelectric signals for an improved control of the prosthetic limb. The Magnetic Bead Tracking System, which will be implanted and used in combination with the e-OPRA Implant system, is an investigational device that consists of pairs of magnetic beads, and a set of magnetic field sensors that measure and track the length of muscles and the speed at which they move in real-time. When the beads are implanted in muscle in the residual limb of an amputee, the muscle length signal is communicated to an investigational, robotic ankle-foot prosthesis. The purpose of the study is to evaluate the feasibility of a transtibial amputee with the e-OPRA Implant System and Magnetic Bead Tracking System exhibiting full neural control over a neuro-mechanical prosthetic system. A maximum of seven subjects will be enrolled. Each subject will undergo one or more surgeries where the e-OPRA Implant System and Magnetic Bead Tracking System will be implanted. The subjects will participate in follow-up sessions the last of which occurs approximately 24 months after the surgery. This is a prospective, non-randomized, uncontrolled study.

Conditions

Amputation

Keywords

prosthesis; osseointegration; neural transmission; magnetic beads

Outcome Measures

Primary Outcomes (2)

• number of participants out of total who undergo device implantation (aim: 7 participants) who can complete robotics testing activities

  testing activities include subject stability assessments, free space control activities using EMG, bead migration assessments, walking gait assessments and single-leg balance assessments

  3 - 24 months postop for all study participants

• number of participants out of total who undergo device implantation (aim: 7 participants) who still have device successfully implanted at 24 months postop

  successful implantation at 24 months is defined as having both eOPRA Implant System and Magnetic Beads Tracking System intact with no plans for removal due to device-related safety concern

  24 months postop for all study participants

Study Arms (1)

eOPRA Implant System for Transtibial Amputees and Magnetic Bead Tracking System

EXPERIMENTAL

Implantation of e-OPRA Implant System and Magnetic Bead Tracking System in lower limb.

Device: eOPRA Implant System for Transtibial Amputees and Magnetic Bead Tracking System

Interventions

eOPRA Implant System for Transtibial Amputees and Magnetic Bead Tracking System DEVICE

The Magnetic Bead Tracking System is an investigational device that consists of pairs of magnetic beads, and a set of magnetic field sensors that measure and track the length of muscles and the speed at which they move in real-time. When the beads are implanted in muscle in the residual limb of an amputee, the muscle length signal is communicated to an investigational, robotic ankle-foot prosthesis. The e-OPRA is an investigational implant system that lets a lower leg prosthesis attach securely to the remaining tibia bone. The e-OPRA device has been designed so that it can be implanted with an electrode set that consists of an electrical connector and electrodes to allow it to be used with both a neuro-mechanical (powered) prosthesis system, in addition to the standard prosthesis. The operation to implant these devices will represent a modification of the surgical technique currently employed for standard below knee amputation.

Also known as: eOPRA, e-Osseointegrated Prosthesis for the Rehabilitation of Amputees

eOPRA Implant System for Transtibial Amputees and Magnetic Bead Tracking System

Eligibility Criteria

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

You may qualify if:

• Male or Female age 22-65 at the time of surgery.
• The subject must already have been implanted with the e-OPRA Implant System at the transtibial level or must have an existing unilateral or bilateral transtibial amputation or a medical condition requiring performance of a unilateral or bilateral transtibial amputation with a minimum of 8 cm of residual tibia after amputation, such that the subject will be implanted with the e-OPRA Implant System. (OPTION 1)
• If the subject does not already have the e-OPRA Implant System, the subject must have undergone independent consultation with at least two lower extremity surgical specialists to ensure they have exhausted all limb salvage options prior to undergoing amputation, as well as a psychiatric evaluation to ensure appropriate capacity and volition. (OPTION 2)
• The patient must have the ability to ambulate at variable cadence (an expected lower extremity prosthesis functional level of K3 or above, as confirmed by study investigators).
• The patient must have adequate soft tissue bulk and muscle mass present in the operative limb to support appropriate wound healing.
• In the opinion of the investigator, normal cognitive function and absence of any physical limitations, addictive diseases or underlying medical conditions that may preclude the patient from being a good study candidate.
• Willingness, ability and commitment to participate in baseline and follow-up evaluations for the full length of the study.
• Willingness and ability to provide informed consent to participate in the study.

You may not qualify if:

• Subjects with any active skin disease in the tested limb.
• Subjects with severe co morbidity, atypical skeletal anatomy, or poor general physical/mental health that, in the opinion of the Investigator, will not allow the subject to be a good study candidate (i.e. other disease processes, mental capacity, substance abuse, shortened life. expectancy, vulnerable patient population, BMI \>40, etc.).
• For subjects who have not yet been implanted with the e-OPRA Implant System, subjects who would have less than 2 mm of remaining cortex bone available around the implant, if implanted.
• Subjects with advanced atrophic muscle and/or compromised soft tissue coverage in the operative limb.
• Subjects with evidence of or a documented history of severe peripheral vascular disease, diabetes mellitus (type I or type II), skin diseases, neuropathy or neuropathic disease and severe phantom pain, or osteoporosis, such that, in the opinion of the investigator, will not allow the subject to be a good study candidate.
• Subjects with a history of systemically administered corticosteroids, immune-suppressive therapy or chemotherapy drugs within six (6) months of implant surgery.
• Subjects with a known need of future MRIs.
• Subjects currently involved in another clinical study where that participation may conflict or interfere with the treatment, follow-up or results of this clinical study.
• Active smokers will be excluded from candidacy; those patients willing to undergo tobacco cessation will need to be completely abstinent from tobacco use for at least 6 weeks preoperatively.
• Women who are pregnant, lactating or planning a pregnancy during the first twelve (12) months of the post-surgical follow-up.
• Subject has an allergy to any component of the device.
• Concurrent illness, disability or geographical residence would hamper attendance at required study visits.

Sponsors & Collaborators

• Brigham and Women's Hospital: lead
• Massachusetts Institute of Technology (MIT): collaborator
• Integrum: collaborator

Study Sites (2)

Brigham and Women's Hospital

Boston, Massachusetts, 02115, United States

Location

MIT Media Lab

Cambridge, Massachusetts, 02139, United States

Location

Study Officials

• Matthew J Carty, MD

  Brigham and Women's Hospital

  PRINCIPAL INVESTIGATOR

• Hugh Herr, PhD

  Massachusetts Institute of Technology

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DEVICE FEASIBILITY
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Roberta and Stephen R. Weiner Distinguished Chair in Surgery, Staff Surgeon BWH

Study Record Dates

• First Submitted: April 23, 2024
• First Posted: April 30, 2024
• Study Start: May 1, 2024
• Primary Completion: May 2, 2026
• Study Completion (Estimated): May 2, 2027
• Last Updated: October 20, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

US (2)