Hand Transplantation Versus Hand Prosthetics: Pros and Cons

Peripheral neural interfaces: Skeletal muscles are hyper-reinnervated according to the axonal capacity of the surgically rewired nerves

Advances in robotics have outpaced the capabilities of man-machine interfaces to decipher and transfer neural information to and from prosthetic devices. We emulated clinical scenarios where high- (facial) or low-neural capacity (ulnar) donor nerves were surgically rewired to the sternomastoid muscle, which is controlled by a very small number of motor axons. Using retrograde tracing and electrophysiological assessments, we observed a nearly 15-fold functional hyper-reinnervation of the muscle after high-capacity nerve transfer, demonstrating its capability of generating a multifold of neuromuscular junctions. Moreover, the surgically redirected axons influenced the muscle's physiological characteristics, by altering the expression of myosin heavy-chain types in alignment with the donor nerve. These findings highlight the remarkable capacity of skeletal muscles to act as biological amplifiers of neural information from the spinal cord for governing bionic prostheses, with the potential of expressing high-dimensional neural function for high-information transfer interfaces.

Reaching New Heights: A Comprehensive Study of Hand Transplantations in Korea after Institutionalization of Hand Transplantation Law

PURPOSE

With the revision of the Organ and Transplantation Act in 2018, the hand has become legal as an area of transplantable organs in Korea. In January 2021, the first hand allotransplantation since legalization was successfully performed, and we have performed a total of three successful hand transplantation since then. By comparing and incorporating our experiences, this study aimed to provide a comprehensive reconstructive solution for hand amputation in Korea.

MATERIALS AND METHODS

Recipients were selected through a structured preoperative evaluation, and hand transplantations were performed at the distal forearm level. Postoperatively, patients were treated with three-drug immunosuppressive regimen, and functional outcomes were monitored.

RESULTS

The hand transplantations were performed without intraoperative complications. All patients had partial skin necrosis and underwent additional surgical procedures in 2 months after transplantation. After additional operations, no further severe complications were observed. Also, patients developed acute rejection within 3 months of surgery, but all resolved within 2 weeks after steroid pulse therapy. Motor and sensory function improved dramatically, and patients were very satisfied with the appearance and function of their transplanted hands.

CONCLUSION

Hand transplantation is a viable reconstructive option, and patients have shown positive functional and psychological outcomes. Although this study has limitations, such as the small number of patients and short follow-up period, we should focus on continued recovery of hand function, and be careful not to develop side effects from immunosuppressive drugs. Through the present study, we will continue to strive for a bright future regarding hand transplantation in Korea.

[Prosthetic Fitting Concepts after Major Amputation in the Upper Limb - an Overview of Current Possibilities]

BACKGROUND

The upper extremity and particularly the hands are crucial for patients in interacting with their environment, therefore amputations or severe damage with loss of hand function significantly impact their quality of life. In cases where biological reconstruction is not feasible or does not lead to sufficient success, bionic reconstruction plays a key role in patient care. Classical myoelectric prostheses are controlled using two signals derived from surface electrodes in the area of the stump muscles. Prosthesis control, especially in high amputations, is then limited and cumbersome. The surgical technique of Targeted Muscle Reinnervation (TMR) offers an innovative solution: The major arm nerves that have lost their target organs due to amputation are rerouted to muscles in the stump area. This enables the establishment of cognitive control signals that allow significantly improved prosthesis control.

PATIENTS/MATERIALS AND METHODS

A selective literature review on TMR and bionic reconstruction was conducted, incorporating relevant articles and discussing them considering the clinical experience of our research group. Additionally, a clinical case is presented.

RESULTS

Bionic reconstruction combined with Targeted Muscle Reinnervation enables intuitive prosthetic control with simultaneous movement of various prosthetic degrees of freedom and the treatment of neuroma and phantom limb pain. Long-term success requires a high level of patient compliance and intensive signal training during the prosthetic rehabilitation phase. Despite technological advances, challenges persist, especially in enhancing signal transmission and integrating natural sensory feedback into bionic prostheses.

CONCLUSION

TMR surgery represents a significant advancement in the bionic care of amputees. Employing selective nerve transfers for signal multiplication and amplification, opens up possibilities for improving myoelectric prosthesis function and thus enhancing patient care. Advances in the area of external prosthetic components, improvements in the skeletal connection due to osseointegration and more fluid signal transmission using wireless, fully implanted electrode systems will lead to significant progress in bionic reconstruction, both in terms of precision of movement and embodiment.

Orthotopic forelimb transplantation in a Yucatan minipig model: Anatomic and in vivo study

INTRODUCTION

Above elbow transplants represent 19% of the upper extremity transplants. Previous large-animal models have been too distal or heterotopic, did not use immunosuppression and had short survival. We hypothesize that an orthotopic forelimb transplant model, under standard immunosuppression, is feasible and can be used to address questions on peri-transplant ischemia reperfusion injury, and post-transplantation vascular, immunologic, infectious, and functional outcomes.

MATERIALS AND METHODS

Four forelimbs were used for anatomical studies. Four mock transplants were performed to establish technique/level of muscle/tendon repairs. Four donor and four recipient female Yucatan minipigs were utilized for in-vivo transplants (endpoint 90-days). Forelimbs were amputated at the midarm and preserved through ex vivo normothermic perfusion (EVNP) utilizing an RBC-based perfusate. Hourly perfusate fluid-dynamics, gases, electrolytes were recorded. Contractility during EVNLP was graded hourly using the Medical Research Council scale. EVNP termination criteria included systolic arterial pressure ≥115 mmHg, compartment pressure ≥30 mmHg (at EVNP endpoint), oxygen saturation reduction of 20%, and weight change ≥2%. Indocyanine green (ICG) angiography was performed after revascularization. Limb rejection was evaluated clinically (rash, edema, temperature), and histologically (BANFF classification) collecting per cause and protocol biopsies (POD 1, 7, 30, 60 and endpoint). Systemic infections were assessed by blood culture and tissue histology. CT scan was used to confirm bone bridging at endpoint.

RESULTS

Animals 2, 4 reached endpoint with grade 0-I rejection. Limbs 1, 3 presented grade III rejection on days 6, 61. CsA troughs averaged 461 ± 189 ng/mL. EVNLP averaged 4.3 ± 0.52 h. Perfusate lactate, PO2 , and pH were 5.6 ± 0.9 mmol/L, 557 ± 72 mmHg and 7.5 ± 0.1, respectively. Muscle contractions were 4 [1] during EVNLP. Transplants 2, 3, 4 showed bone bridging on CT.

CONCLUSION

We present preliminary evidence supporting the feasibility of an orthotopic, mid-humeral forelimb allotransplantation model under standard immunosuppression regimen. Further research should validate the immunological, infectious, and functional outcomes of this model.

Meat grinder hand injury in children: A report of 5 cases

BACKGROUND

Meat grinder injury is considered one of the leading causes that may result in mutilating hand injury. It is commonly occurred in children due to negligence, limited awareness and inexperience about the machine processing and its possible complications.

CASE PRESENTATION

We reported five cases of grinder-induced hand injuries, presented with their hands yet firmly wedged inside the grinder. Each hand was freed from inside of the grinder by reversed turning of the machine except for one case which needed extrication with the using of a cutting torch. After releasing of the injured hand, we performed amputation at the wrist level in two cases, at metacarpophalangeal levels in one case and we could perform revascularization in two cases.

CONCLUSION

Meat grinder hand injuries in children is challenging, gentle and careful releasing of the hand without causing further damages along with meticulous repair of hand structure to restore hand function. The most important thing is to prevent household meat-grinder-related injuries through keeping it away from the reach of the children's hand.

A Systematic Review of the Reported Complications Related to Facial and Upper Extremity Vascularized Composite Allotransplantation

INTRODUCTION

Twenty three years after the first successful upper extremity transplantation, the role of vascularized composite allotransplantation (VCA) in the world of transplantation remains controversial. Face and upper extremity reconstruction via transplantation have become successful options for highly selected patients with severe tissue and functional deficit when conventional reconstructive options are no longer available. Despite clear benefit in these situations, VCA has a significant potential for complications that are more frequent when compared to visceral organ transplantation. This study intended to perform an updated systematic review on such complications.

MATERIALS AND METHODS

MEDLINE database via PubMed, Embase and Cochrane Library were searched. Face and upper extremity VCA performed between 1998 and 2021 were included in the study. Relevant media and press conferences reports were also included. Complications related to face and upper extremity VCA were recorded and reviewed including their clinical characteristics and complications.

RESULTS

One hundred fifteen patients underwent facial (43%) or upper extremity (57%) transplantation. Overall, the surgical complication rate was 23%. Acute and chronic rejection was identified in 89% and 11% of patients, respectively. Fifty eight percent of patients experienced opportunistic infection. Impaired glucose metabolism was the most common immunosuppression-related complication other than infection. Nineteen percent of patients ultimately experienced partial or complete allograft loss.

CONCLUSIONS

Complications related to VCA are a significant source of morbidity and potential mortality. Incidence of such complications is higher than previously reported and should be strongly emphasized in patient consent process. Strict patient selection criteria, complex preoperative evaluation, consideration of alternatives, and thorough disclosure to patients should be routinely performed prior to VCA indication.

Applying Health Utility Outcome Measures and Quality-Adjusted Life-Years to Compare Hand Allotransplantation and Myoelectric Prostheses for Upper Extremity Amputations

BACKGROUND

An amputation of the upper extremity not only is devastating for the patient's physical, emotional, and social well-being but also constitutes a financial stress for both the patient and the health care system. The objective of this study was to determine the utility and quality-adjusted life-years of hand allotransplantation versus myoelectric prostheses and to compare these measures in patients afflicted with unilateral versus bilateral amputations.

METHODS

A survey was administered on bilateral amputees, unilateral amputees, replantation patients, and healthy controls. Patient demographics, functional patient-reported outcomes, quality-of-life questionnaires, and utility outcome measures were calculated for four different scenarios: hand transplantation and myoelectric prostheses with or without complications.

RESULTS

Five bilateral amputees, 12 unilateral amputees, nine replantation patients, and 45 healthy controls completed the survey. The highest quality-adjusted life-years were obtained in the replantation patient group for the scenario of myoelectric prosthesis without complications (mean, 34.8 years). Altogether, there was no statistically significant difference between hand transplantation and myoelectric prostheses (p = 0.36). On subgroup analysis, unilateral amputees reported significantly higher quality-adjusted life-years for myoelectric prostheses rather than hand transplantation (6.4; p = 0.0015), whereas bilateral amputees did not demonstrate a significant difference (-2.4; p = 0.299).

CONCLUSIONS

Utility and quality-adjusted life-years do not differ significantly between hand transplantation and myoelectric prostheses, except in unilateral amputees with myoelectric prostheses, who had higher quality-of-life scores. Based on trends from this pilot study, myoelectric prostheses may be considered for unilateral amputees, whereas no superiority can be demonstrated between both treatments in bilateral amputees.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Descriptive Study of Patients With Upper Limb Amputation As Possible Candidates for a Hand Transplant in Medellín, Colombia

Introduction

The amputation of the upper limb, especially of the hand, is a serious trauma with significant functional and psychological impact. Treatment options include adaptation to the stump, use of prostheses, and composite tissue transplantation. Unfortunately, in Colombia, to date, there are no epidemiological data that characterize the sociodemographic and clinical variables of patients with upper limb amputation.

Objective

To describe the clinical and epidemiological characteristics of patients with upper limb amputation in two hospital institutions in the city of Medellín during the period 2018-2019 as a basis for developing a hand transplant program in Colombia.

Methods

A descriptive cross-sectional study was carried out where a total of 443 medical records were reviewed, of which eight records that met the inclusion criteria were identified. Variables such as age, etiology of amputation, level of amputation, comorbidities, complications, and rehabilitation process were analyzed. The information was collected in the REDCap program, and a descriptive analysis was carried out with the data obtained.

Results

From a sample of 443 amputee patients, eight were selected that met the inclusion criteria. There were 7/8 men (87%) aged 43 years. A total of 75% came from rural areas. In 3/8 patients, there was amputation of the dominant limb. The most common mechanisms were shear trauma and crushing in the context of an occupational accident. A total of 50% had a complete extra-hospital amputation, and reimplantation was not attempted in any of the cases. The most frequent levels of amputation were the proximal and distal third of the forearm. The longest follow-up time was 12 months. Only two patients mentioned the possibility of using a prosthesis during rehabilitation.

Conclusions

Three young patients were identified, without comorbidities, with amputation of the dominant limb in the context of an occupational accident and without the possibility of rehabilitation with prostheses who benefit from a possible future hand transplant. However, it is necessary to implement a composite tissue transplantation program and public health policies that allow this procedure to be performed in Colombia.

Evaluating Treatment Preferences and Perceptions of a Prosthetic Versus a Transplanted Hand: A Conjoint Analysis-Based Study

INTRODUCTION

This study used a conjoint analysis-based survey to assess which factors are most influential when considering treatment with a prosthesis or transplant after a unilateral hand amputation.

METHODS

Overall, 469 respondents were recruited using Amazon Mechanical Turk and asked to assume that they experienced a hand amputation. To determine preferences for a prosthetic, respondents chose among 11 pairs of alternatives with variations in the following attributes: appearance, function, maintenance, and learning time. Respondents were then presented with descriptions of the risks and outcomes of hand transplantation. The most compelling reasons for and against a transplant were determined and characteristics predictive of support for a transplant were identified.

RESULTS

The most important attributes for a prosthesis were "lifelike appearance" and "myolectric function." For hand transplantation, respondents were most concerned about immunosuppression side effects (n = 323, 69%) and the intense nature of surgery (n = 275, 59%), whereas the most positive benefit was the concept of the transplant being "natural" (n = 339, 72%). When faced with the choice of a hand transplant or a prosthetic, approximately 50% of respondents chose a transplantation. Younger age, previous medical experiences, a perceived "familiarity with medical issues," and the regular attendance of religious services were associated with strong support for a hand transplantation (P < 0.01).

CONCLUSIONS

When considering a hand prosthesis, respondents are motivated most by appearance and function. Meanwhile, with hand transplantation, the risks of immunosuppression and the intense nature of surgery and recovery are predominant concerns. These findings may help inform patient-physician discussions when considering treatment after unilateral hand amputation.

Comparison of health state utility measures and disabilities of arm, shoulder and hand questionnaire scores in bilateral hand amputees

Bilateral hand amputation (BHA) is a life-changing event that can result in a great degree of loss of function. Prosthetic limb replacement and composite tissue allotransplantation are the treatment options. Understanding the BHA in terms of economic utility will help direct future research and upgrading in healthcare delivery. This is a cross-sectional study in 32 BHA who have completed a minimum of six months after wound healing. The primary objective was to assess the convergent validity of three different health utility (HU) derivation methods, namely the time trade-off (TTO), EuroQol questionnaire (EQ-5D-5L), and EuroQol visual analog scale (EQ-VAS) among BHA. The secondary objective was to correlate the disabilities of arm, shoulder and hand (DASH) scores with the HU scores and see whether the DASH score predicts the HU scores derived by different methods. The mean (SD) HU scores for TTO, VAS, and EQ-5D-5L were 0.34 (0.25), 0.61 (0.25), and 0.46 (0.20), respectively. HU derived by the TTO method displayed a weak correlation with EuroQol-based derivatives (EQ-VAS & EQ-5D-5L). But there was a moderate correlation between values by EQ-VAS & EQ-5D-5L. Hence, the EuroQol HU derivative is preferable to TTO. The mean (SD) of the DASH score was 48.4 (22.9). There was a strong correlation between the DASH scores and HU derived by different methods. Also, the DASH score is seen to be a good predictor of HU scores. This study is the first to derive HU and correlate the DASH with HU scores in the BHA scenario .

Pediatric Hand Transplantation: A Decision Analysis

Background: The first successful bilateral pediatric hand transplant was performed in 2015. Previous hand transplant decision analysis models have focused on the adult population. This model principally aimed to determine whether adverse outcomes associated with immunosuppression outweigh the benefits of performing bilateral hand transplant surgery in a pediatric candidate. The model also conceptualized the valuation of losing years of life and sought to determine the impact of that valuation on the surgical decision. Methods: A decision model compared undergoing bilateral hand transplant surgery with using prosthetics for an 8-year-old patient. The outcome measure used was quality adjusted life years (QALYs), and sensitivity analysis was performed on the immunosuppressive risks associated with the surgical decision, as well as the perceived valuation of aversion to life years lost. Results: The decision to perform surgery was marginally optimal compared to the prosthetic decision (50.11 QALY vs. 47.95 QALY). A Monte Carlo simulation revealed that this difference may be too marginal to detect an optimal decision (50.14 ± 8.28 QALY vs. 47.95 ± 2.12 QALY). Sensitivity analysis identified decision thresholds related to immunosuppression risks (P = 29% vs. P = 33% modeled), and a trend of increasing risk as a patient is more averse to losing life years. Conclusions: The marginally optimal treatment strategy currently is bilateral hand transplant, compared to prosthetics for pediatric patients. Key determinants of the future optimal strategy will be whether immunosuppressive regimens become safer, with a reduced risk of losing life years due to immunosuppressive complications, and whether prosthetics become more acceptable and enable higher functioning.

Grinder Injury of the Hand: A Rare but Devastating Occupational Hazard

Food handlers and workers are exposed to several occupational hazards not frequented by the general population. Grinder injuries of the hand present a devastating consequence of industrial food processing that is infrequently described. Herein, we describe two cases that presented to our department with meat grinder injuries of the hand.

Hand Transplantation-Risks and Benefits

Composite tissue allotransplantation (CTA) is the culmination of progress in transplantation, allowing the reconstruction of the hand in amputees. Worldwide, more than 100 procedures have been performed. The aim of this work was to understand the hand allotransplantation approach, making known current aspects, risks, and benefits. A PubMed research was realized between October 2018 and March 2019, including terms like "Hand transplantation" AND "Composite tissue allotransplantation," "Hand transplantation" AND "Functional outcomes," "Hand transplantation" AND "Immunosuppression," "Hand prosthetics," "Hand Transplantation" AND "Ethics." There were included papers between 1995 and 2018, with English language, amputee human adults, systematic reviews, and clinical studies. Seventy-two papers were fully evaluated. There are technical aspects that influence the procedure like team coordination or surgical technique. It requires a long-life treatment, which has risks such as toxicity or infections. However, it allows the recovery of fine movements, and independence, to perform detailed tasks. The indications must be carefully considered, because some patients benefit from the use of prosthesis. CTA has become an option for amputees so it is important to do more research, to determine the benefits of this procedure. It is not considered a life-saving procedure, so there is an ethical debate because of the risks.

A review of technology, materials and R&D challenges of upper limb prosthesis for improved user suitability

Introduction

Hand amputation significantly challenges one's independence in carrying out daily activities. With the UK and Italy recoding circa 5200 and 3500 upper limb (UL) amputations (ULAs) yearly, respectively, and about 541,000 Americans losing ULs in 2005, incidence victims constitute a considerable proportion of our population and should be adequately supported. The use of upper limb prosthesis (ULP) offers amputees a new opportunity of living a quality life - but poses challenges on the physically and psychologically traumatised. With reports that up to 20% of adult UL amputees choose not to use a prosthesis, roughly 26% of adults and 45% of children and adolescents are dissatisfied with their devices and abandon them with reasons of poor solution to basic needs, a review of ULP for suitability has become crucial.

Objectives

These include, to review UL prosthetic technology (PT), the materials used in the manufacturing of ULP, challenges in research and development of ULP, and to advise on the suitability of different devices to the needs of amputees.

Methods

They involve an extensive review of relevant literature and application of statistics to analyse data obtained from literature.

Results

ULAs are characterised to show affected bones in seven types of amputations. The characterisation depicts key causes of incidences that lead to amputations while advising on device suitability. PT is classified in terms of cost, nature, functions/operations of each type of device while providing the design challenges. Users' opinions on PT materials are analysed and used to suggest new materials for the next generation of the devices. R&D challenges hindering future developments of PT is reviewed and results used to identify characteristics for the next generation of the technology.

Conclusions

To increase user satisfaction and reduce device abandonment, amputees need useful information on the trend in PT and engineers need information about device field performance for improvements. The use of better performing ULP will improve users' everyday lives.

Does pediatric hand transplantation undermine a child's right to an open future?

To date, pediatric hand transplantations have only been performed twice. The ethical issue most often discussed in the literature on this surgery concerns the risks of immunosuppression. While these risks are significant, they can be at least partially mitigated by selecting for patients who are already immunocompromised. Nevertheless, as we will argue, pediatric hand transplantation raises ethical issues that go beyond the risks of immunosuppression. In this paper, we focus on three additional ethical issues: the fact that pediatric hand transplantation aims to improve, rather than save life; the fact that it is an experimental surgery; and the fact that it will be performed on non-autonomous patients whose 'right to an open future' may potentially be undermined by the surgery. Taken together, we think that these considerations suggest that transplantation should be postponed until a child is mature enough to make their own decision about it.

Cadaveric Bilateral Proximal Forearm Allotransplantation

Until, sometime ago, microsurgery meant mainly covering a defect or replanting severed parts back to where they belong. Now, restoration of original function and aesthetic consideration is a must in planning reconstructive procedure. Hand transplant combines hand surgery and microsurgery with complex multidisciplinary care.At the anniversary of our first cadaveric bilateral proximal forearm transplantation done in the country's government institute, we would like to share our experience in performing the surgery, outcomes so far, complications, and lessons learned, to contribute to the growing knowledge of vascularized composite allotransplant.

Early recovery of neuronal functioning in the sensory cortex after nerve reconstruction surgery

BACKGROUND

Nerve reconstructive surgery induces a transient loss and a prolonged and a gradual return of sensory inputs to the brain. It is unknown whether, following this massive peripheral denervation, the brain will experience a prolonged period of severe, intrinsic dysfunction.

OBJECTIVE

We aim to investigate the mechanisms of return of processing function in cortical neurons.

METHODS

We used the whisker model in rats to evaluate the functional recovery in the somatosensory cortex after a nerve reconstruction surgery. Multi-unit recording in the barrel cortex was performed in lightly anesthetized rats while their whiskers were stimulated by a whisker stimulator.

RESULTS

We observed a loss of neuronal responses to whisker stimulation 1 week after surgery, which started to recover 2 weeks after surgery. Following the surgery, only 11.8% of units had principle whiskers (PWs) returned to their original status while 17.7% had PWs different from their original status, indicating the effect of aberrant reinnervation on the whisker response map.

CONCLUSIONS

Robust neuronal responses to sensory stimulation even when only sparse sensory inputs are available in the early recovery phase. During this phase, aberrant reinnervation induces disorganized whisker tuning, a finding that might be account for the hypoesthesia and paresthesia during early recovery after nerve reconstruction.

Bionic reconstruction : Restoration of extremity function with osseointegrated and mind-controlled prostheses

Background

Loss of an extremity at any level has a major impact on a patient’s life. Using bionic reconstruction, extremity function can be restored and the patient reintegrated into daily life. Surgical procedures including selective nerve transfer and anchoring of prostheses into bone are combined with structured rehabilitation and modern prosthetic fitting. The patient is thereby able to use the prostheses intuitively and with multiple degrees of freedom.

Methods

This article presents the concept and approach for modern bionic reconstruction in detail and the relevant literature. The nerve transfer matrices for targeted muscle reinnervation (TMR) and the concept of osseointegration to optimally fit a patient with a modern prosthesis are described in detail. As a clinical example, the case of a patient who suffered from traumatic amputation and subsequently received TMR in combination with an osseointegrated implant and structured rehabilitation is presented.

Results

Using bionic reconstruction, basic hand functions can be restored and bimanual dexterity can expand the range of daily activities. Besides this approach to bionic reconstruction, its advantages and disadvantages are compared to hand transplantation. The limitations and perspectives of modern bionic reconstruction are also discussed.

Conclusions

Bionic reconstruction is a sophisticated method for restoring extremity function and nowadays can be considered a standard of care for all levels of upper extremity amputations. An interdisciplinary approach and structured rehabilitation are necessary to master prosthetic function to ultimately reintegrate patients into daily life.

Bionic hand as artificial organ: Current status and future perspectives

Even though the hand comprises only 1% of our body weight, about 30% of our central nervous systems (CNS) capacity is related to its control. The loss of a hand thus presents not only the loss of the most important tool allowing us to interact with our environment, but also leaves a dramatic sensory-motor deficit that challenges our CNS. Reconstruction of hand function is therefore not only an essential part of restoring body integrity and functional wholeness but also closes the loop of our neural circuits diminishing phantom sensation and neural pain. If biology fails to restore meaningful function, today we can resort to complex mechatronic replacement that have functional capabilities that in some respects even outperform biological alternatives, such as hand transplantation. As with replantation and transplantations, the challenge of bionic replacement is connecting the target with the CNS to achieve natural and intuitive control. In recent years, we have developed a number of strategies to improve neural interfacing, signal extraction, interpretation and stable mechanical attachment that are important parts of our current research. This work gives an overview of recent advances in bionic reconstruction, surgical refinements over technological interfacing, skeletal fixation, and modern rehabilitation tools that allow quick integration of prosthetic replacement.

Selective motor fascicle transfer and neural-machine interface: case report

An amputated nerve transferred to a nearby muscle produces a transcutaneously detectable electromyographic signal corresponding to the transferred nerve; this technique is known as targeted muscle reinnervation (TMR). There are 2 issues to overcome to improve this technique: the caliber and the selectivity of the transferred nerve. It is optimal to select and transfer each motor fascicle to achieve highly developed myoelectric arms with multiple degrees-of-freedom motion. The authors report on a case in which they first identified the remnant stumps of the amputated median and radial nerves and then identified the sensory fascicles using somatosensory evoked potentials. Each median nerve fascicle was transferred to the long head branch of the biceps or the brachialis branch, while the short head branch of the biceps was retained for elbow flexion. Each radial nerve fascicle was transferred to the medial or lateral head branch of the triceps, while the long head branch of the triceps was retained for elbow extension. Electrophysiological and functional tests were conducted in the reinnervated muscles. Functional and electrophysiological improvement was noted, with marked improvement in the identification rate for each digit, forearm, and elbow motion after the selective nerve transfers. The authors note that more selective nerve transfers may be required for the development of prostheses with multiple degrees of freedom.

Transplants for non-lethal conditions: a case against hand transplantation in minors

Human allografts for life-threatening organ failure have been demonstrated to be lifesaving and are now considered to be standard of care for many conditions. Transplantation of non-vital anatomic body parts has also been accomplished. Hand transplantation after limb loss in adults has been shown to offer some promising benefits in both functional and psychological measures in preliminary studies. It has been suggested to expand eligibility criteria to include minors, with one such operation having already been performed. With this in mind, we examine the current state of hand transplantation research in the context of available alternatives. We examine the ethics of carrying out these operations in minors, including under the protections of clinical research. We argue that children should not be considered for this surgery due to the substantial risks of immunosuppressive medication, the likelihood that the graft will need to be replaced during the patient's lifetime and the lack of significant compensatory advantages over modern prosthetics.

Innovations in reconstructive microsurgery: Reconstructive transplantation

In the past 20 years, reconstructive transplantation (RT) has emerged as a viable reconstructive option for carefully selected patients. More than 100 upper extremity and 40 face transplants have been performed worldwide to date. Concomitantly, the portfolio of reconstructive transplantation has been extended by additional procedures such as lower extremities, abdominal wall, neck, uterus, genitourinary, and pediatric transplants. In the present review article, we aim to summarize the current state of knowledge about this exciting field.

Ex-vivo flush of the limb allograft reduces inflammatory burden prior to transplantation

BACKGROUND

Passenger leucocytes and inflammatory debris transferred from the donor limb to the recipient can induce allorecognition, which activates the host immune response. This is the first study to evaluate whether the transfer of this inflammatory burden can be reduced via post-preservation flush prior to revascularisation, and whether this is influenced by ischaemia.

METHODS

Bilateral forelimbs from the same pig were procured and infused with preservation flush and stored on ice. Each limb from the same pig underwent a post-preservation intravascular flush with isotonic solution at either 2 or 6 h. Venous effluent underwent flow cytometry to phenotype leucocyte populations, with additional quantification of cytokines and cell-free DNA.

RESULTS

We identified large populations of viable leucocytes in the flush effluent (8.65 × 10⁸ ± 3.10 × 10⁸ cells at 2 h and 1.02 × 10⁹ ± 2.63 × 10⁸ at 6 h). This comprised T cells, B cells, NK cells and monocytes. Post-preservation flush yielded significant concentrations of pro-inflammatory cytokines including IL-6, IL-18, GM-CSF, IL-1β, IL1α and CXCL-8 and mitochondrial DNA. The regulatory cytokine, IL-10 was undetectable.

CONCLUSIONS

This study supports the finding that a post-preservation flush removes leucocytes and inflammatory components that are responsible for direct presentation. This study also gives an indication of how ischaemia impacts on the inflammatory burden transferred to the recipient upon reperfusion.

Outcomes after hand and upper extremity transplantation

Hand and upper extremity transplantation (HUET) has emerged as the most frequently performed reconstructive procedure in the burgeoning field of vascularized composite allotransplantation (VCA). VCA refers to a form of transplant with multiple tissue types that represents a viable treatment option for devastating injuries where conventional reconstruction would be unable to restore form and function. As hand transplantation becomes increasingly more common, discussions on advantages and disadvantages of the procedure seem to intensify. Despite encouraging functional outcomes, current immunosuppressive regimens with their deleterious side-effect profile remain a major concern for a life-changing but not life-saving type of transplant. In addition, a growing number of recipients with progressively longer follow-up prompt the need to investigate potential long-term sequelae, such as chronic rejection. This review will discuss the current state of HUET, summarizing outcome data on graft survival, motor and sensory function, as well as immunosuppressive treatment. The implications of these findings for VCA in terms of achievements and challenges ahead will then be discussed.

What Is New in Trauma-Related Amputations

Traumatic and trauma-related amputations represent unfortunate sequelae of severe injury, but should not be viewed as a treatment failure and may represent the best reconstructive option for some patients. Lessons from recent military conflicts have guided the evolution of modern surgical techniques and rehabilitation management of this challenging patient population, and treatment at a specialty center may improve patient outcomes. Despite appropriate management, however, surgical complications remain common and revision surgery is often necessary. Bridge synostosis procedures remain controversial, and clinical equipoise remains regarding their functional benefits. Based on European experience over the last 3 decades, osseointegration has evolved into a viable clinical alternative for patients unable to achieve acceptable function using conventional sockets, and several devices are being developed or tested in the United States. Targeted muscle reinnervation and advanced pattern recognition may dramatically improve the functional potential of many upper extremity amputees, and the procedure may also relieve neuroma-related pain. Furthermore, exciting new research may eventually facilitate haptic feedback and restore useful sensation for amputees. Natural disasters and global terrorism events, in addition to conventional trauma resulting in limb loss, make a working knowledge of current amputation surgical techniques essential to the practicing orthopaedic trauma surgeon.

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.