Osseointegrated Transtibial Prosthesis With Neural Interface — TTeOPRA  

Amputation Clinical Trial

Official title: An Osseointegrated Transtibial Prosthesis Offering Long-Term Bi-Directional Efferent-Afferent Neural Transmission

Status Recruiting

Clinical Trial 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 purpose of the study is to evaluate the feasibility of a transtibial amputee with the e-OPRA Implant System exhibiting full neural control over a neuro-mechanical prosthetic system.

A maximum of two subjects will be enrolled. Each subject will undergo a surgery where the e-OPRA Implant System will be implanted. The subjects will participate in follow-up sessions of which the last one occurs approximately 24 months after the surgery. This is a prospective, non-randomized, uncontrolled study.

Clinical Trial Description

Normalization of function for individuals with limb amputation is within reach, and will be achieved by smart implants capable of bi-directional communication between brain and machine via bone-anchored, interactive, powered prosthetic components. Rehabilitation of patients with expected high physical activity level, such as after amputation due to trauma or cancer, is currently limited by dependence on an external socket for the mechanical attachment of the prosthesis to the residuum. Despite the use of advanced materials and fabrication methods, socket interfaces routinely cause sores, chafing, pain, increased energy expenditure, and a decreased quality of life. Novel surgical techniques using osseointegrated transdermal titanium implants, now validated in Europe for 25 years, obviate the need for painful sockets by establishing a direct, load-bearing link between skeleton and prosthesis. This system also promises a transformative breakthrough in neuroprosthetics, because it allows for fully internal, high bandwidth, stable neural connections. In a paper recently published in Science Translational Medicine, implanted muscle and nerve cuff electrodes were added to the osseointegrated device, creating a bi-directional efferent-afferent interface utilizing a safe and immune-sealed osseo-conduit. Commenting on this work, the editor stated, "Osseointegration could revolutionize the field of neuroprosthetics, giving patients more intuitive control and more freedom of movement."

Investigators have sought to advance bionic prostheses with sufficient degrees of freedom for performing natural tasks, such as manipulating objects in the case of upper-extremity prostheses, or walking and running for lower-extremity systems. Nonetheless, afferent feedback has not played a major role in any clinically-viable amputation prostheses, despite being critical for biomimetic control. This deficiency can, in large part, be attributed to a lack of clinically-available methodologies for sustained communication with the peripheral nervous system. There is no existing platform capable of invasive, robust, and permanent communication with the peripheral nervous system in a high-demand clinical setting. Only by bringing together critical technologies and expertise will it be possible to create a bionic limb replacement system with adequate suspension, load transmission, motor control, proprioceptive feedback, and external mechatronics that resemble the mass, volume and dynamics of the missing biological limb.

To achieve such an unprecedented integration of prosthetic technology, a broad scientific team has been assembled with members from Massachusetts Institute of Technology (MIT: Carty, Herr, Riso, Braanemark), Brigham and Women's Hospital (BWH: Carty), University of California, San Francisco (UCSF: O'Donnell), University of Michigan (U-M: Cederna), and Walter Reed National Military Medical Center (WRNMMC: Forsberg, Potter). With this combination of leading technologists and clinicians in the fields of biomechanics, osseointegration, prosthetics, implantable electrodes, sensory feedback, proprioception, reconstructive surgery, and mechatronics, we seek to develop the most advanced clinically-viable artificial limb. With proprioceptive afferent feedback, we seek to demonstrate that a person with transtibial amputation can exhibit full volitional control over a neuro-mechanical prosthetic system where key walking metrics are normalized, including preferred speed, metabolism and joint dynamics. It is the view of the proposers that the scope of this research is fundamental wherein the results will be shared broadly within the scientific community. ;

Related Conditions & MeSH terms

• Amputation

• NCT number: NCT05249049
• Study type: Interventional
• Source: Massachusetts Institute of Technology
• Contact: Hugh M Herr, PhD
• Phone: 617-314-3661
• Email: hherr@media.mit.edu
• Status: Recruiting
• Phase: N/A
• Start date: November 3, 2021
• Completion date: April 15, 2023