Cutting Edge Bionics in Highly Impaired Individuals: A Case of Challenges and Opportunities.

Highly impaired individuals stand to benefit greatly from cutting-edge bionic technology, however concurrent functional deficits may complicate the adaptation of such technology. Here, we present a case in which a visually impaired individual with bilateral burn injury amputation was provided with a novel transradial neuromusculoskeletal prosthesis comprising skeletal attachment via osseointegration and implanted electrodes in nerves and muscles for control and sensory feedback. Difficulties maintaining implant hygiene and donning and doffing the prosthesis arose due to his contralateral amputation, ipsilateral eye loss, and contralateral impaired vision necessitating continuous adaptations to the electromechanical interface. Despite these setbacks, the participant still demonstrated improvements in functional outcomes and the ability to control the prosthesis in various limb positions using the implanted electrodes. Our results demonstrate the importance of a multidisciplinary, iterative, and patient-centered approach to making cutting-edge technology accessible to patients with high levels of impairment.

A highly integrated bionic hand with neural control and feedback for use in daily life.

Restoration of sensorimotor function after amputation has remained challenging because of the lack of human-machine interfaces that provide reliable control, feedback, and attachment. Here, we present the clinical implementation of a transradial neuromusculoskeletal prosthesis-a bionic hand connected directly to the user's nervous and skeletal systems. In one person with unilateral below-elbow amputation, titanium implants were placed intramedullary in the radius and ulna bones, and electromuscular constructs were created surgically by transferring the severed nerves to free muscle grafts. The native muscles, free muscle grafts, and ulnar nerve were implanted with electrodes. Percutaneous extensions from the titanium implants provided direct skeletal attachment and bidirectional communication between the implanted electrodes and a prosthetic hand. Operation of the bionic hand in daily life resulted in improved prosthetic function, reduced postamputation, and increased quality of life. Sensations elicited via direct neural stimulation were consistently perceived on the phantom hand throughout the study. To date, the patient continues using the prosthesis in daily life. The functionality of conventional artificial limbs is hindered by discomfort and limited and unreliable control. Neuromusculoskeletal interfaces can overcome these hurdles and provide the means for the everyday use of a prosthesis with reliable neural control fixated into the skeleton.

Loads on Transhumeral Amputees Using Osseointegrated Prostheses.

The treatment of the upper extremities is not as prevalent as that of the lower limbs, but it is nonetheless equally important. Today, there are no load data relating to upper extremity bone-anchored prosthesis users in the literature, but they are important in order to improve the rehabilitation protocol, design aspects and confidence of the user when it comes to loading the prosthesis in daily life. The aim of the present study was to investigate, in a population of eleven transhumeral amputees with osseointegrated implants, the load levels reached during specific prosthetic movements at maximum voluntary effort and during daily activities. The data showed a wide range of maximum load levels throughout the different activities. Furthermore, the data indicate that some test subjects felt apprehensive about loading the prosthesis, resulting in relatively low loads compared with the group as a whole. Within the limits of the present study, it was concluded that loading the implant system was subject specific, which resulted in large subject-to-subject variability. Moreover, some subjects exhibited uncertainty about the levels that could damage the fixation or the implant system. The study illustrates the diversity and uncertainty that exist in a population of transhumeral amputees treated with bone-anchored prostheses in terms of loading in daily life.

Osseointegration amputation prostheses on the upper limbs: methods, prosthetics and rehabilitation.

BACKGROUND: The osseointegration programme for upper extremity amputation started in Sweden in 1990, when a titanium fixture was first implanted into a thumb. This method has since been used for transhumeral and below-elbow amputation. The treatment involves two surgical procedures. During the first a titanium fixture is surgically attached to the skeleton, and a second procedure six months later involves a skin penetrating abutment to which the prosthesis is attached. OBJECTIVES: To describe the osseointegration procedure for surgery, prosthetics and rehabilitation. METHODS: Patients with short stumps and previous problems with prosthetic fitting were selected. From 1990 to April 2010, 37 upper limb cases were treated and fitted with prosthesis: 10 thumbs, 1 partial hand, 10 transradial and 16 transhumeral amputations. Of these, 7 patients are currently not prosthetic users. RESULTS: Patients indicated that function and quality of life had improved since osseointegration. CONCLUSION: Osseointegration is an important platform for present and future prosthetic technology. The prosthetic situation is improved due to the stable fixation, freedom of motion and functionality. CLINICAL RELEVANCE: The two-stage osseointegration procedure has the potential to change the rehabilitation strategy for selected upper limb amputees. The method eliminates the need for a socket and the prosthesis will always fit. The stable prosthetic fixation and increased freedom of motion generates improved function. Specially designed components and rehabilitation procedures have been developed.