An Osseointegrated Transfemoral Prosthesis Offering Long-Term Bi-Directional Efferent-Afferent Neural Transmission
1 other identifier
interventional
2
1 country
1
Brief Summary
The purpose of the study is to investigate the clinical and functional outcomes of a transfemoral amputation with osseointegrated titanium implant, AMI muscle constructs, and implanted electrodes in the domain of gait, free space control, and embodiment.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for not_applicable
Started Apr 2017
Longer than P75 for not_applicable
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
April 15, 2017
CompletedPrimary Completion
Last participant's last visit for primary outcome
July 18, 2025
CompletedFirst Submitted
Initial submission to the registry
October 10, 2025
CompletedFirst Posted
Study publicly available on registry
May 29, 2026
CompletedStudy Completion
Last participant's last visit for all outcomes
July 17, 2026
CompletedMay 29, 2026
May 1, 2026
8.3 years
October 10, 2025
May 22, 2026
Conditions
Outcome Measures
Primary Outcomes (6)
Kinematic Measures of Lower-Limb Biomechanics
Quantitative analysis of joint angles, during level-ground walking, stair negotiation, and other functional tasks. Outcomes will be assessed using a motion capture system (e.g., Vicon) and embedded prosthesis sensors.
An average of 2 sessions in the span of 1 week
Spatiotemporal Gait Parameters
Evaluation of stance-to-swing ratio during ambulation. Parameters will be obtained using a motion capture system (e.g., Vicon) and an instrumented walkway. Data will be analyzed to assess functional walking ability and compared to normative or baseline values.
An average of 2 sessions in the span of 1 week
Assessment of Patient Ability to Control each Joint of the Prosthesis
Assessment of volitional control of the powered knee and ankle joints via neural signals from the residual limb. Participants will perform isolated joint control trials in seated positions. Outcomes include joint command accuracy evaluated using surface electromyography (EMG) and motion capture. These measures will quantify the participant's ability to intentionally control each prosthetic joint.
An average of 2 sessions in the span of 1 week
Ground Reaction Forces
Quantitative analysis of ground reaction forces during level-ground walking, stair negotiation, and other functional tasks. Outcomes will be assessed using instrumented force plates.
An average of 2 sessions in the span of 1 week
Joint Torques
Quantitative analysis of joint torques during level-ground walking, stair negotiation, and other functional tasks. Outcomes will be assessed using a motion capture system (e.g., Vicon), instrumented force plates, and embedded prosthesis sensors.
An average of 2 sessions in the span of 1 week
Walking speed
Evaluation of walking speed during ambulation. Parameters will be obtained using a motion capture system (e.g., Vicon) and an instrumented walkway. Data will be analyzed to assess functional walking ability and compared to normative or baseline values.
An average of 2 sessions in the span of 1 week
Study Arms (1)
Osseointegration surgery
EXPERIMENTALTransfemoral amputation with osseointegrated titanium implant, AMI muscle constructs, and implanted electrodes
Interventions
MIT powered knee prosthesis developed by the MIT Biomechatronics Group.
Eligibility Criteria
You may qualify if:
- Male or Female age 22-65 at the time of surgery.
- The patient must have a medical condition requiring performance of a unilateral transfemoral amputation with a minimum of 13 cm of residual femur after amputation, and: A. At a minimum level of amputation of 20 cm or greater above the knee joint line if physical therapy and prosthetist evaluation is commensurate with a standard K3 ambulatory status; or, B. At a minimum level of amputation of 16 cm above the knee joint line as part of a single- stage procedure if physical therapy and prosthetist evaluation is commensurate with a more active K3 or less active K4 postoperative ambulatory status.
- 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.
- The patient must have the ability to ambulate at variable cadence (an expected lower extremity prosthesis functional level of K3 or above).
- The patient must have adequate bone stock to support the implanted device.
- In the opinion of the investigators, normal cognitive function and absence of any physical limitations, addictive diseases or underlying medical conditions that may preclude patient from being a good surgical and/or study candidate.
- Willingness, ability and commitment to participate in baseline and follow-up evaluations for the full length of the study including the prescribed rehabilitation program.
- Written informed consent to participate in the study provided by the patient or legal representative.
You may not qualify if:
- Women who are pregnant, lactating or planning a pregnancy during the first twelve (12) months of the post-surgical follow- up.
- Subjects who have not been completely abstinent from tobacco use for at least 6 weeks preoperatively.
- Active infection or dormant bacteria.
- Subjects would have less than 2 mm of remaining cortex bone available around the implant, if implanted.
- 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.
- Evidence of any active skin disease involving the proposed surgical limb.
- History of systemically administered corticosteroids, immune- suppressive therapy or chemotherapy drugs within six (6) months of implant surgery.
- 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.).
- The patient is currently involved in another clinical study where that participation may conflict or interfere with the treatment, follow-up or results of this clinical study.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Integrumcollaborator
- Massachusetts Institute of Technologylead
Study Sites (1)
MIT Media Lab
Cambridge, Massachusetts, 02139, United States
Study Officials
- PRINCIPAL INVESTIGATOR
Hugh Herr, PhD
Massachusetts Institute of Technology
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- NA
- Masking
- NONE
- Purpose
- BASIC SCIENCE
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
October 10, 2025
First Posted
May 29, 2026
Study Start
April 15, 2017
Primary Completion
July 18, 2025
Study Completion
July 17, 2026
Last Updated
May 29, 2026
Record last verified: 2026-05
Data Sharing
- IPD Sharing
- Will not share
Individual participant data (IPD) will not be shared. This study involves a small cohort and a particular surgical procedure. Even with direct identifiers removed, the combination of clinical timelines and outcomes could increase the risk of re-identification. Summary/aggregate results (and selected analyses) have been reported in a peer-reviewed publication.