An Osseoanchored Percutaneous Prosthesis Study Evaluating Stable Neural Signal Transmission in Subjects With Transhumeral Amputations

An Osseoanchored Percutaneous Prosthesis Study Evaluating Stable Neural Signal Transmission in Subjects With Transhumeral Amputations

This early feasibility study proposes to evaluate use of the electronic-Osseoanchored Prostheses for the Rehabilitation of Amputees (e-OPRA) device, a transhumeral implant system for direct skeletal anchorage of amputation prostheses, with a test prosthesis. The e-OPRA System is being investigated to better understand the ability to improve the functionality of the prosthesis and enhance the sense of embodiment of the prosthesis itself. This will be a 10 subject Early Feasibility Study in which the primary objective is to capture preliminary safety and effectiveness information on the implanted e-OPRA system. With the addition of electrodes to the muscle segments, this biological interface allows for both the extraction of fine motor control signals from the nerve fascicles and the generation of sensory percepts via electrical stimulation of the muscles. In addition, electrodes placed on muscles within the residuum with native vascularization and innervation also allow the extraction of critical motor control signals and the generation of sensory feedback through muscle stimulation. The electrical activity recorded from these muscle segments (called electromyography or EMG) is specific to certain movements and can be used to determine precisely how a person wants to move their arm and hand. Use of the e-OPRA device with the well-documented neuro-electronic capabilities of EMG control systems provides an alternative to traditional socket prostheses by establishing a direct, loadbearing link between the patient's skeleton and prosthesis.

Inclusion Criteria:

• Male or female age 22-65 at the time of surgery.

• The patient must have one of the following medical conditions:

  • A condition requiring performance of a unilateral transhumeral amputation;
  • An existing transhumeral OPRA device implanted under IDE G150155;
  • An existing unilateral transhumeral amputation; or
  • An existing unilateral transhumeral amputation with previous nerve reinnervation surgery.

• The patient must have a residual humerus of greater than or equal to 10 cm.

• The patient must have a cortical thickness of at least 1.5 mm.

• The patient must have at least a portion of biceps and triceps muscles present.

• The subject must have undergone consultation with at least two upper extremity surgical specialists to ensure they have exhausted all limb salvage options prior to undergoing amputation.

• 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.

Exclusion Criteria:

• Women who are pregnant, lactating, or planning a pregnancy during the first twelve (12) months of the post-surgical follow-up.
• Arthrosis of the ipsilateral glenohumeral joint by radiographs.
• Subjects who have not been completely abstinent from tobacco use for at least 6 weeks preoperatively.
• Active or dormant infection.
• Evidence of or a documented history of severe peripheral vascular disease, diabetes mellitus (type I or type II), skin diseases, neuropathy, neuropathic disease, severe phantom pain, or osteoporosis, such that, in the opinion of the Investigator, the subject will not be a good study candidate.
• History of systemically administered corticosteroids, immunosuppressive therapy, or chemotherapeutic drugs within six (6) months of implant surgery.
• Severe medical 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, other indwelling electronic implants, mental incapacity, substance abuse, shortened life expectancy, and vulnerable patient population).
• Current involvement in another clinical study where that participation may conflict or interfere with the treatment, follow-up or results of this clinical study.