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

Running, not enrolling · Not applicable

Conditions studied: Amputation

In brief

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.

Key facts

Study ID: NCT06391697
Run by: Brigham and Women's Hospital
People needed: 7
Starts: 2024-05-01
Expected to finish: 2027-05-02
Last updated by the study team: 2026-07-09

Who can join

Age: 22 and older, up to 65. Sex: any. Healthy volunteers: not accepted.

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.

Where it is running

Brigham and Women's Hospital — Boston, Massachusetts, United States
MIT Media Lab — Cambridge, Massachusetts, United States

Full record on ClinicalTrials.gov

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