Functional and Psychosocial Outcomes of Hand Transplantation Compared with Prosthetic Fitting in Below-Elbow Amputees:A Multicenter Cohort Study

BACKGROUND:Hand-transplantation and improvements in the field of prostheses opened new frontiers in restoring hand function in below-elbow amputees. Both concepts aim at restoring reliable hand function, however, the indications, advantages and limitations for each treatment must be carefully considered depending on level and extent of amputation. Here we report our findings of a multi-center cohort study comparing hand function and quality-of-life of people with transplanted versus prosthetic hands. METHODS:Hand function in amputees with either transplant or prostheses was tested with Action Research Arm Test (ARAT), Southampton Hand Assessment Procedure (SHAP) and the Disabilities of the Arm, Shoulder and Hand measure (DASH). Quality-of-life was compared with the Short-Form 36 (SF-36). RESULTS:Transplanted patients (n = 5) achieved a mean ARAT score of 40.86 ± 8.07 and an average SHAP score of 75.00 ± 11.06. Prosthetic patients (n = 7) achieved a mean ARAT score of 39.00 ± 3.61 and an average SHAP score of 75.43 ± 10.81. There was no significant difference between transplanted and prosthetic hands in ARAT, SHAP or DASH. While quality-of-life metrics were equivocal for four scales of the SF-36, transplanted patients reported significantly higher scores in "role-physical" (p = 0.006), "vitality" (p = 0.008), "role-emotional" (p = 0.035) and "mental-health" (p = 0.003). CONCLUSIONS:The indications for hand transplantation or prosthetic fitting in below-elbow amputees require careful consideration. As functional outcomes were not significantly different between groups, patient's best interests and the route of least harm should guide treatment. Due to the immunosuppressive side-effects, the indication for allotransplantation must still be restrictive, the best being bilateral amputees

Prosthetic hand and arm replacement in upper limb amputees

Die Amputation oder der Funktionsverlust der oberen Extremität stellt ein einschneidendes Erlebnis für betroffene Patienten dar. Der prothetische Arm- bzw. Handersatz hat aufgrund Verbesserungen der Steuerungsmöglichkeiten deutlich an Beachtung gewonnen. Die Prothesensteuerung konnte mittels kognitiver Nerventransfers im Stumpfbereich sowie neuen rehabilitativen Konzepten deutlich verbessert werden. Dadurch konnte auch die Indikation zum prothetischen Hand- bzw. Armersatz bei Patienten mit Funktionsverlust erweitert werden. Die biotechnologische Schnittstelle konnte durch die Multiplizierung der verfügbaren Muskelsignale im Stumpfbereich verbessert werden. Dies wird mittels kognitiver Nerventransfers erreicht, welche die Information der amputierten Armnerven des Plexus brachialis im Bereich der Stumpfmuskulatur wieder verfügbar machen. Mit diesen Signalen wird eine intuitive und simultane Prothesensteuerung der verschiedenen artifiziellen Gelenke ermöglicht, ohne der Notwendigkeit, permanent zwischen den verschiedenen prothetischen Funktionen zu wechseln. Das Ziel dieser Arbeit war es, die Ergebnisse der prothetischen Rekonstruktion im Bereich der oberen Extremität zu evaluieren und diese mit Patienten nach Handtransplantation zu vergleichen. Im Rahmen einer Multicenterstudie konnte erstmals ein direkter Vergleich von prothetischen und transplantierten Händen auf ähnlicher Amputationshöhe mittels objektiver Handfunktionstests durchgeführt werden. Die Ergebnisse dieser Studie zeigten keine signifikanten Unterschiede zwischen den beiden Patientenpopulationen wodurch die Schlussfolgerung gezogen wurde, dass die Handtransplantation nur bei beidseitig Hand-Amputierten indiziert sein sollte, da bei diesen Patienten durch die zusätzliche Rekonstruktion einer Sensibilität der Greiforgane die Handtransplantation den Prothesen klar überlegen ist. Weiters wird in dieser Arbeit das Konzept der bionischen Rekonstruktion vorgestellt. Dieser neue Therapieansatz ermöglicht die Rekonstruktion sinnvoller Handfunktion bei Patienten mit funktionsloser Hand bzw. Arm z.B. nach schwerwiegenden Verletzungen des Plexus brachialis. In diesen Patienten wird nach nervenchirurgischer Vorbereitung und intensivem neurophysiologischem Training eine elektive Amputation durchgeführt, um eine prothetische Rekonstruktion zu ermöglichen. Die verschiedenen Therapieansätze dieser Arbeit sollen die Funktionalität und dadurch auch die Akzeptanz myoelektrischer Hand-/Armprothesen in den verschiedenen Patientenpopulationen verbessern.Amputation or loss of functional capacity of the upper extremity represents a decisive event for affected patients. The prosthetic hand and arm replacement gained attention as a therapeutic option due to refinements in prosthetic control mechanisms. The use of cognitive nerve transfers together with new concepts of prosthetic rehabilitation expanded the indication for prosthetic limb replacement. The biotechnological interface is improved by increasing the number of available myosignals at the stump region. This is achieved using cognitive nerve transfers, thus, amplifying the information of the amputated nerves for hand and arm function to the residual muscles. With these, intuitive and simultaneous prosthetic control of the different artificial joints is made possible which leads to a more natural control of the replaced limb without the necessity to alter between the various prosthetic functions. The goal of this thesis was to evaluate the results of prosthetic hand or limb replacement and compare these with the functional outcome after hand allograft. Within a multicenter study we could perform a unique direct comparison of prosthetic and transplanted hands at similar level of amputation with objective hand function outcome measures. The results of this study could not show any significant difference between both patient populations. Therefore we concluded that hand transplantation should only be indicated in bilateral hand loss as the possible reconstruction of sensory capacity outweighs the risks in these patients and the overall results can be far superior to prosthetic substitution. Furthermore, the concept of bionic reconstruction is presented within this thesis. This new treatment modality enables reconstruction of meaningful hand function in patients with functionless hand or arm after e.g. severe damage of the brachial plexus. In these patients an elective amputation is performed after nerve-surgical preparation and intensive neurophysiological training in order to enable a prosthetic reconstruction. The different therapeutic approaches of this thesis are intended to improve the functionality and thus also the acceptance of myoelectric hand and arm prostheses in the different patient populations.submitted by Dr. med. univ. Stefan Amadeus SalmingerZusammenfassung in deutscher SpracheAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersMedizinische Universität Wien, Dissertation, 2017OeB

Prothetischer Ersatz an der oberen Extremität bei Amputation oder Funktionsverlust

Hintergrund Die Indikation zum prothetischen Ersatz der oberen Extremität wurde in den letzten Jahren von der klassischen Amputation auch auf Patienten mit Verlust oder angeborenen Defiziten der Hand- und Armfunktion ausgeweitet. Des Weiteren wurde die Steuerung myoelektrischer Hand- und Armprothesen mittels selektiver Nerventransfers im Stumpfbereich deutlich verbessert. Fragestellung Übersicht über die chirurgischen, therapeutischen und prothetischen Möglichkeiten bei Amputationen oder Funktionsverlust der oberen Extremität. Material und Methode Es erfolgte eine selektive Literaturrecherche unter Berücksichtigung eigener Erfahrungen des klinischen Alltags und Durchsicht von Patientenakten. Ergebnisse Die elektive Amputation mit prothetischem Ersatz führt bei Patienten mit funktionsloser Hand zu einer deutlichen Verbesserung der Hand- und Armfunktion und zeigt dadurch auch substanzielle Verbesserungen der Lebensqualität in diesem speziellen Patientengut. Im Falle einer hohen Amputation ermöglichen selektive Transfers der Nerven des Plexus brachialis auf die verbliebene Stumpfmuskulatur die Etablierung von bis zu 6 Signalgebern, wodurch intuitiv und simultan die verschiedenen prothetischen Gelenke gesteuert werden können. Auf diese Weise ist eine deutlich effizientere Steuerung möglich, ohne zwischen den verschiedenen Steuerungsebenen der Prothese wechseln zu müssen. Schlussfolgerung Der prothetische Ersatz der oberen Extremität stellt nicht nur den Goldstandard nach Amputationen dar, sondern ermöglicht auch für Patienten mit funktionsloser Hand aufgrund massiver Weichteil- oder Nervenverletzung sowie angeborener Defekte eine funktionelle Wiederherstellung.Background The indication for prosthetic replacement of the upper extremity could be extended in recent years from classic amputation to patients suffering loss or congenital deficits of hand and arm function. Additionally, the control of myoelectric hand and arm prostheses could be improved by the use of selective nerve transfers. Objectives Overview regarding surgical, therapeutical and prosthetic options after amputations or loss of function of the upper extremity. Methods Selective literature search including the authors own experience in everyday clinical practice as well as a review of medical records. Results Elective amputation in combination with prosthetic replacement in patients after loss of hand function can achieve remarkable improvements in hand and arm function, as well as quality of life in this special patient cohort. In cases of high-level amputations selective nerve transfers of the brachial plexus to remaining stump muscles can establish up to six myosignals to achieve intuitive and simultaneous control of the different prosthetic functions. In this way, more efficient control of the prosthetic device is possible without the need to change between the different artificial joints. Conclusion The prosthetic replacement of the upper extremity does not only represent the gold standard for amputees, but also offers useful reconstruction for patients suffering loss of hand and arm function after massive soft tissue or nerve trauma as well as congenital deficiencies.(VLID)365887

Noninvasive, accurate assessment of the behavior of representative populations of motor units in targeted reinnervated muscles

Targeted muscle reinnervation (TMR) redirects nerves that have lost their target, due to amputation, to remaining muscles in the region of the stump with the intent of establishing intuitive myosignals to control a complex prosthetic device. In order to directly recover the neural code underlying an attempted limb movement, in this paper, we present the decomposition of high-density surface electromyographic (EMG) signals detected from three TMR patients into the individual motor unit spike trains. The aim was to prove, for the first time, the feasibility of decoding the neural drive that would reach muscles of the missing limb in TMR patients, to show the accuracy of the decoding, and to demonstrate the representativeness of the pool of extracted motor units. Six to seven flexible EMG electrode grids of 64 electrodes each were mounted over the reinnervated muscles of each patient, resulting in up to 448 EMG signals. The subjects were asked to attempt elbow extension and flexion, hand open and close, wrist extension and flexion, wrist pronation and supination, of their missing limb. The EMG signals were decomposed using the Convolution Kernel Compensation technique and the decomposition accuracy was evaluated with a signal-based index of accuracy, called pulse-to-noise ratio (PNR). The results showed that the spike trains of 3 to 27 motor units could be identified for each task, with a sensitivity of the decomposition > 90%, as revealed by PNR. The motor unit discharge rates were within physiological values of normally innervated muscles. Moreover, the detected motor units showed a high degree of common drive so that the set of extracted units per task was representative of the behavior of the population of active units. The results open a path for a new generation of human-machine interfaces in which the control signals are extracted from noninvasive recordings and the obtained neural information is based directly on the spike trains of motor neurons

Prosthetic Embodiment and Body Image Changes in Patients Undergoing Bionic Reconstruction Following Brachial Plexus Injury

Funding Information: The authors would like to thank Aron Cserveny for the preparation of the illustrations included in the manuscript. Furthermore, we thank Xaver Fuchs, Kristina Staudt, Herta Flor, and Martin Diers from Zentralinstitut f?r Seelische Gesundheit Mannheim (Germany) for their input regarding the formulation of the statements evaluating prosthetic embodiment. Funding. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 810346) and the Academy of Finland under project Hi-Fi BiNDIng (No 333149). Publisher Copyright: © Copyright © 2021 Sturma, Hruby, Boesendorfer, Pittermann, Salminger, Gstoettner, Politikou, Vujaklija, Farina and Aszmann. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.Brachial plexus injuries with multiple-root involvement lead to severe and long-lasting impairments in the functionality and appearance of the affected upper extremity. In cases, where biologic reconstruction of hand and arm function is not possible, bionic reconstruction may be considered as a viable clinical option. Bionic reconstruction, through a careful combination of surgical augmentation, amputation, and prosthetic substitution of the functionless hand, has been shown to achieve substantial improvements in function and quality of life. However, it is known that long-term distortions in the body image are present in patients with severe nerve injury as well as in prosthetic users regardless of the level of function. To date, the body image of patients who voluntarily opted for elective amputation and prosthetic reconstruction has not been investigated. Moreover, the degree of embodiment of the prosthesis in these patients is unknown. We have conducted a longitudinal study evaluating changes of body image using the patient-reported Body Image Questionnaire 20 (BIQ-20) and a structured questionnaire about prosthetic embodiment. Six patients have been included. At follow up 2.5–5 years after intervention, a majority of patients reported better BIQ-20 scores including a less negative body evaluation (5 out of 6 patients) and higher vital body dynamics (4 out of 6 patients). Moreover, patients described a strong to moderate prosthesis embodiment. Interestingly, whether patients reported performing bimanual tasks together with the prosthetic hand or not, did not influence their perception of the prosthesis as a body part. In general, this group of patients undergoing prosthetic substitution after brachial plexus injury shows noticeable inter-individual differences. This indicates that the replacement of human anatomy with technology is not a straight-forward process perceived in the same way by everyone opting for it.Peer reviewe

Distal Nerve Transfers in High Peroneal Nerve Lesions: An Anatomical Feasibility Study

The peroneal nerve is one of the most commonly injured nerves of the lower extremity. Nerve grafting has been shown to result in poor functional outcomes. The aim of this study was to evaluate and compare anatomical feasibility as well as axon count of the tibial nerve motor branches and the tibialis anterior motor branch for a direct nerve transfer to reconstruct ankle dorsiflexion. In an anatomical study on 26 human body donors (52 extremities) the muscular branches to the lateral (GCL) and the medial head (GCM) of the gastrocnemius muscle, the soleus muscle (S) as well as the tibialis anterior muscle (TA) were dissected, and each nerve’s external diameter was measured. Nerve transfers from each of the three donor nerves (GCL, GCM, S) to the recipient nerve (TA) were performed and the distance between the achievable coaptation site and anatomic landmarks was measured. Additionally, nerve samples were taken from eight extremities, and antibody as well immunofluorescence staining were performed, primarily evaluating axon count. The average diameter of the nerve branches to the GCL was 1.49 ± 0.37, to GCM 1.5 ± 0.32, to S 1.94 ± 0.37 and to TA 1.97 ± 0.32 mm, respectively. The distance from the coaptation site to the TA muscle was 43.75 ± 12.1 using the branch to the GCL, 48.31 ± 11.32 for GCM, and 19.12 ± 11.68 mm for S, respectively. The axon count for TA was 1597.14 ± 325.94, while the donor nerves showed 297.5 ± 106.82 (GCL), 418.5 ± 62.44 (GCM), and 1101.86 ± 135.92 (S). Diameter and axon count were significantly higher for S compared to GCL as well as GCM, while regeneration distance was significantly lower. The soleus muscle branch exhibited the most appropriate axon count and nerve diameter in our study, while also reaching closest to the tibialis anterior muscle. These results indicate the soleus nerve transfer to be the favorable option for the reconstruction of ankle dorsiflexion, in comparison to the gastrocnemius muscle branches. This surgical approach can be used to achieve a biomechanically appropriate reconstruction, in contrast to tendon transfers which generally only achieve weak active dorsiflexion

Peripheral nerve transfers change target muscle structure and function

Selective nerve transfers surgically rewire motor neurons and are used in extremity reconstruction to restore muscle function or to facilitate intuitive prosthetic control. We investigated the neurophysiological effects of rewiring motor axons originating from spinal motor neuron pools into target muscles with lower innervation ratio in a rat model. Following reinnervation, the target muscle's force regenerated almost completely, with the motor unit population increasing to 116% in functional and 172% in histological assessments with subsequently smaller muscle units. Muscle fiber type populations transformed into the donor nerve's original muscles. We thus demonstrate that axons of alternative spinal origin can hyper-reinnervate target muscles without loss of muscle force regeneration, but with a donor-specific shift in muscle fiber type. These results explain the excellent clinical outcomes following nerve transfers in neuromuscular reconstruction. They indicate that reinnervated muscles can provide an accurate bioscreen to display neural information of lost body parts for high-fidelity prosthetic control.peerReviewe

Functional outcomes.

<p>Functional outcomes.</p