Updates in Targeted Sensory Reinnervation for Upper Limb Amputation

Current Surgery Reports, Mar 2014

Advanced robotic devices capable of simulating the dexterous ability of the upper limb with an array of internal sensors have raised the enticing prospect of replacing the lost intricate functions of the arm following upper limb amputation. However, a large gap still exists in the application of this technology to the human user. In particular, the ability to provide physiologically relevant sensory feedback—to have the amputee feel the prosthetic hand as their own—has not yet been achieved. Although a number of different approaches are being investigated, targeted sensory reinnervation, a refinement of the original targeted muscle reinnervation procedure, is the most recent and promising development in the effort to create a functional human–machine interface with a closed loop sensory feedback system. This technique aims to re-establish hand sensation on the skin so that it can be readily accessed non-invasively during functional tasks. Recent efforts are being directed towards distributing hand maps widely on the stump without interference of sensations from the native area. In this article, we will review the surgical approaches that have been used for sensory reinnervation in upper arm amputation and compare the resultant outcomes and potential functional utility of the techniques.

A PDF file should load here. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser.

Alternatively, you can download the file locally and open with any standalone PDF reader:

https://link.springer.com/content/pdf/10.1007%2Fs40137-013-0045-7.pdf

Updates in Targeted Sensory Reinnervation for Upper Limb Amputation

Jacqueline S. Hebert 0 1 2 3 4 Kate Elzinga 0 1 2 3 4 K. Ming Chan 0 1 2 3 4 Jaret Olson 0 1 2 3 4 Michael Morhart 0 1 2 3 4 0 K. M. Chan Division of Physical Medicine and Rehabilitation, Centre for Neuroscience, 5005 Katz Group Centre, University of Alberta , Edmonton , AB T5R 2E1, Canada 1 K. Elzinga Division of Plastic Surgery, University of Alberta , 2207-8210 111 St NW, Edmonton , AB T6G 2C7, Canada 2 J. S. Hebert (&) Division of Physical Medicine and Rehabilitation, Glenrose Rehabilitation Hospital, University of Alberta , Rm 1239, 10230-111 Ave, Edmonton , AB T5G 0B7, Canada 3 M. Morhart Division of Plastic Surgery, University of Alberta , 303 East Tower, 14310 111 Ave NW, Edmonton , AB T5M 3Z7, Canada 4 J. Olson Division of Plastic Surgery, University of Alberta , 82-8440 112 St NW, 2D3 WMC, Edmonton , AB T6G 2B7, Canada Advanced robotic devices capable of simulating the dexterous ability of the upper limb with an array of internal sensors have raised the enticing prospect of replacing the lost intricate functions of the arm following upper limb amputation. However, a large gap still exists in the application of this technology to the human user. In particular, the ability to provide physiologically relevant sensory feedbackto have the amputee feel the prosthetic hand as their ownhas not yet been achieved. Although a number of different approaches are being investigated, targeted sensory reinnervation, a refinement of the original targeted muscle reinnervation procedure, is the most recent and promising development in the effort to create a functional human-machine interface with a closed loop sensory feedback system. This technique aims to reestablish hand sensation on the skin so that it can be readily accessed non-invasively during functional tasks. Recent efforts are being directed towards distributing hand maps widely on the stump without interference of sensations from the native area. In this article, we will review the surgical approaches that have been used for sensory reinnervation in upper arm amputation and compare the resultant outcomes and potential functional utility of the techniques. - Despite major advances in engineered technology, proximal upper limb amputation remains one of the most difficult challenges for prosthetic replacement. Individuals with proximal levels of arm amputation have a higher rate of rejection of prostheses in comparison to more distal levels of amputation [1, 2]. Reasons for rejection are widely varied. The main concerns from myoelectric users that limit use of the prosthesis include poor durability, poor dexterity, and lack of sensory feedback [3]. In response to these concerns, artificial limbs with up to 22 degrees of freedom have been developed in an attempt to design a natural limb replacement device with greater function [46]. However, despite the existence of multifunctional prosthetic limbs and efforts to deploy these into clinical practice, challenges with implementation include difficulties attaching the device to the patient, insufficient motor control strategies to control the additional degrees of freedom, and lack of sensory feedback from the device to the human operator. Advances are being made with novel socket designs to improve comfort and suspension [7], and there is ongoing research into percutaneous skeletal attachment to allow direct connection of the prosthesis to the skeletal system [8]. Emerging motor control strategies such as pattern recognition algorithms are promising in the potential ability to control multiple actions of the prosthetic limb [9]. However, designing a method to restore natural sensation from the prosthetic limb is still an unsolved challenge in the effort to restore dexterous hand function following upper limb loss. Developing a neural humanmachine interface that receives and decodes sensory information is a difficult task. The importance of natural, physiologic sensation cannot be overlooked when attempting to restore sensory function to an artificial limb. Various types of sensory feedback from prosthetic devices have been trialed in the past [10, 11] but with no success in clinical translation or long-term usage. This is likely because substitution methods had to be usedthat is, the amputee would have to be trained to understand that an unnatural (or non-physiologic) stimulus meant that something of importance was happening to the prosthesis. This form of sensory substitution can work in controlled settings; however, it has not lead to long-term adoption. The basis for rejection of the feedback device may be that it does not tap into natural sensory mechanisms or provide a percept that enhances the feeling that the prosthesis belongs to the individual as their own hand. Neural interfaces in both the peripheral and central nervous system have been developed as a method to provide sensory feedback. Peripheral nerve stimulation, as a mechanism for restoring sensory information from the prosthetic device to (...truncated)


This is a preview of a remote PDF: https://link.springer.com/content/pdf/10.1007%2Fs40137-013-0045-7.pdf

Jacqueline S. Hebert, Kate Elzinga, K. Ming Chan, Jaret Olson, Michael Morhart. Updates in Targeted Sensory Reinnervation for Upper Limb Amputation, Current Surgery Reports, 2014, pp. 45, Volume 2, Issue 3, DOI: 10.1007/s40137-013-0045-7