Idiopathic Fistula in an Unrepaired Submucous Cleft Palate.

Palatal fistulae are a recognised complication in individuals who have undergone surgical repair of a cleft palate, however, congenital or idiopathic palatal fistulae are rare. This report discusses the presentation and treatment of a 16-year-old female with a submucous cleft palate, who presented with a recent onset change in speech and evidence of a new palatal fistula. There was no history of recent infection or known trauma, and the patient had not undergone any previous palatal surgery. This report discusses the clinical presentation, recommended management and relevant literature for this rare phenomenon.

Chronic Exertional Compartment Syndrome Requiring Bilateral Fasciotomy: An Atypical Complication of Familial Stiff Skin Syndrome in a Father and Son.

ABSTRACT: Stiff skin syndrome (SSS) is a rare cutaneous disorder characterized by cutaneous fibrosis resulting in the early onset of thickened and indurated skin, joint mobility restrictions, and contractures. We describe a father and son with familial SSS who presented with bilateral exertional pain and a confirmed diagnosis of chronic exertional compartment syndrome on 4-compartment pressure testing. Patients experienced restored functionality with bilateral 4-compartment fasciotomy. Chronic exertional compartment syndrome should be considered in the differential diagnosis of patients with SSS and chronic pain of the lower limbs.

Axonal components of nerves innervating the human arm.

OBJECTIVE: Axons traveling within the brachial plexus are responsible for the dexterous control of human arm and hand movements. Despite comprehensive knowledge on the topographical anatomy of nerves innervating the human upper limbs, the definite quantity of sensory and motor axons within this neural network remains elusive. Our aim was to perform a quantitative analysis of the axonal components of human upper limb nerves based on highly specific molecular features from spinal cord level to the terminal nerves at wrist level. METHODS: Nerve specimen harvest at predefined harvesting sites (plexus roots and cords as well as major nerves originating from the brachial plexus innervating the arm and hand) was performed in 9 human heart-beating organ donors. Double immunofluorescence staining using antibodies against choline-acetyltransferase and neurofilament was performed to differentiate motor and sensory axons on nerve cross sections. RESULTS: Three hundred fifty thousand axons emerge from the spinal cord to innervate the human upper limb, of which 10% are motor neurons. In all nerves studied, sensory axons outnumber motor axons by a ratio of at least 9:1. The sensory axon contribution increases when moving distally, whereas only 1,700 motor axons reach the hand to innervate the intrinsic musculature. INTERPRETATION: Our results suggest that upper limb motor execution, and particularly dexterous coordination of hand movement, require an unexpectedly low number of motor neurons, with a large convergence of afferent input for feedback control. Ann Neurol 2017;82:396-408.

Bionic reconstruction to restore hand function after brachial plexus injury: a case series of three patients.

BACKGROUND: Brachial plexus injuries can permanently impair hand function, yet present surgical reconstruction provides only poor results. Here, we present for the first time bionic reconstruction; a combined technique of selective nerve and muscle transfers, elective amputation, and prosthetic rehabilitation to regain hand function. METHODS: Between April 2011, and May 2014, three patients with global brachial plexus injury including lower root avulsions underwent bionic reconstruction. Treatment occurred in two stages; first, to identify and create useful electromyographic signals for prosthetic control, and second, to amputate the hand and replace it with a mechatronic prosthesis. Before amputation, the patients had a specifically tailored rehabilitation programme to enhance electromyographic signals and cognitive control of the prosthesis. Final prosthetic fitting was applied as early as 6 weeks after amputation. FINDINGS: Bionic reconstruction successfully enabled prosthetic hand use in all three patients. After 3 months, mean Action Research Arm Test score increased from 5·3 (SD 4·73) to 30·7 (14·0). Mean Southampton Hand Assessment Procedure score improved from 9·3 (SD 1·5) to 65·3 (SD 19·4). Mean Disabilities of Arm, Shoulder and Hand score improved from 46·5 (SD 18·7) to 11·7 (SD 8·42). INTERPRETATION: For patients with global brachial plexus injury with lower root avulsions, who have no alternative treatment, bionic reconstruction offers a means to restore hand function. FUNDING: Austrian Council for Research and Technology Development, Austrian Federal Ministry of Science, Research & Economy, and European Research Council Advanced Grant DEMOVE.

Targeted Muscle Reinnervation: Surgical Protocol for a Randomized Controlled Trial in Postamputation Pain.

Over the past decade, the field of prosthetics has witnessed significant progress, particularly in the development of surgical techniques to enhance the functionality of prosthetic limbs. Notably, novel surgical interventions have had an additional positive outcome, as individuals with amputations have reported neuropathic pain relief after undergoing such procedures. Subsequently, surgical techniques have gained increased prominence in the treatment of postamputation pain, including one such surgical advancement - targeted muscle reinnervation (TMR). TMR involves a surgical approach that reroutes severed nerves as a type of nerve transfer to "target" motor nerves and their accompanying motor end plates within nearby muscles. This technique originally aimed to create new myoelectric sites for amplified electromyography (EMG) signals to enhance prosthetic intuitive control. Subsequent work showed that TMR also could prevent the formation of painful neuromas as well as reduce postamputation neuropathic pain (e.g., Residual and Phantom Limb Pain). Indeed, multiple studies have demonstrated TMR's effectiveness in mitigating postamputation pain as well as improving prosthetic functional outcomes. However, technical variations in the procedure have been identified as it is adopted by clinics worldwide. The purpose of this article is to provide a detailed step-by-step description of the TMR procedure, serving as the foundation for an international, randomized controlled trial (ClinicalTrials.gov, NCT05009394), including nine clinics in seven countries. In this trial, TMR and two other surgical techniques for managing postamputation pain will be evaluated.

Regenerative Peripheral Nerve Interface: Surgical Protocol for a Randomized Controlled Trial in Postamputation Pain.

Surgical procedures, including nerve reconstruction and end-organ muscle reinnervation, have become more prominent in the prosthetic field over the past decade. Primarily developed to increase the functionality of prosthetic limbs, these surgical procedures have also been found to reduce postamputation neuropathic pain. Today, some of these procedures are performed more frequently for the management and prevention of postamputation pain than for prosthetic fitting, indicating a significant need for effective solutions to postamputation pain. One notable emerging procedure in this context is the Regenerative Peripheral Nerve Interface (RPNI). RPNI surgery involves an operative approach that entails splitting the nerve end longitudinally into its main fascicles and implanting these fascicles within free denervated and devascularized muscle grafts. The RPNI procedure takes a proactive stance in addressing freshly cut nerve endings, facilitating painful neuroma prevention and treatment by enabling the nerve to regenerate and innervate an end organ, i.e., the free muscle graft. Retrospective studies have shown RPNI's effectiveness in alleviating postamputation pain and preventing the formation of painful neuromas. The increasing frequency of utilization of this approach has also given rise to variations in the technique. This article aims to provide a step-by-step description of the RPNI procedure, which will serve as the standardized procedure employed in an international, randomized controlled trial (ClinicalTrials.gov, NCT05009394). In this trial, RPNI is compared to two other surgical procedures for postamputation pain management, specifically, Targeted Muscle Reinnervation (TMR) and neuroma excision coupled with intra-muscular transposition and burying.

Primary prophylaxis for venous thromboembolism in people undergoing major amputation of the lower extremity.

BACKGROUND: Patients undergoing major amputation of the lower limb are at increased risk of venous thromboembolism (VTE). Risk factors for VTE in amputees include advanced age, sedentary lifestyle, longstanding arterial disease and an identifiable hypercoagulable condition. Evidence suggests that pharmacological prophylaxis (for example heparin, factor Xa inhibitors, vitamin K antagonists, direct thrombin inhibitors, antiplatelets) is effective in preventing deep vein thrombosis (DVT) but it is associated with an increased risk of bleeding. Mechanical prophylaxis (for example antiembolism stockings, intermittent pneumatic compression and foot impulse devices), on the other hand, is non-invasive and has no side effects. However, it is not always appropriate in patients with contraindications such as peripheral arterial disease (PAD), arteriosclerosis or bilateral lower limb amputations. It is important to determine the most effective thromboprophylaxis and whether this is one treatment alone or in combination with another. To date, no systematic review has been conducted examining the effectiveness of thromboprophylaxis in preventing VTE in people undergoing amputation. OBJECTIVES: To determine the effectiveness of thromboprophylaxis in preventing VTE in people undergoing major amputation of the lower extremity. SEARCH METHODS: The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2013) and CENTRAL (2013, Issue 4). Clinical trials databases were searched (May 2013). No date or language restrictions were applied. Non-English trials were translated where required and reference lists of identified studies were handsearched. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised controlled trials in which people undergoing a major unilateral or bilateral amputation (for example hip disarticulation, transfemoral, knee disarticulation and transtibial) of the lower extremity were allocated to different types or regimens of thromboprophylaxis (including pharmacological or mechanical prophylaxis) or placebo. DATA COLLECTION AND ANALYSIS: Selection of studies, data extraction and risk of bias were completed independently by two review authors. Any disagreements were resolved by discussion. Meta-analysis could not be completed as the two included studies compared different treatments and therefore the data could not be pooled. MAIN RESULTS: Two studies with a combined total of 288 participants met the inclusion criteria for this review. One study compared low molecular weight heparin with unfractionated heparin and found no difference between the treatments in the prevention of DVT (odds ratio (OR) 1.23, 95% confidence interval (CI) 0.28 to 5.35). No bleeding events or deaths occurred. This study was open label and therefore at a high risk of performance bias. Additionally, the method of randomisation was not reported and therefore the risk of selection bias was unclear. In the second study heparin did not significantly improve prevention of pulmonary embolism (OR 1.02, 95% CI 0.44 to 2.37) when compared to placebo. Furthermore, when the level of amputation was considered, the incidence of pulmonary embolism was similar between the two treatment groups: above knee amputation (OR 0.79, 95% CI 0.31 to 1.97) and below knee amputation (OR 1.53, 95% CI 0.09 to 26.43). Ten participants died during the study; five underwent a post-mortem and three were found to have had a recent pulmonary embolism, all of whom had been on placebo. Bleeding events were reported in less than 10% of participants in both treatment groups but specific data were not presented. This study did not report the methods used to conceal allocation of treatment and therefore it was unclear if selection bias occurred. However, this study appeared to be free from all other sources of bias. No study looked at mechanical prophylaxis. AUTHORS' CONCLUSIONS: As only two studies were included in this review, each comparing different interventions, there is insufficient evidence to make any conclusions regarding the most effective thromboprophylaxis regimen in patients undergoing lower limb amputation. Further large-scale studies that are of good quality are required.

Biomechanical Analysis of Body Movements of Myoelectric Prosthesis Users During Standardized Clinical Tests.

OBJECTIVE: The objective clinical evaluation of user's capabilities to handle their prosthesis is done using various tests which primarily focus on the task completion speed and do not explicitly account for the potential presence of compensatory motions. Given that the excessive body compensation is a common indicator of inadequate prosthesis control, tests which include subjective observations on the quality of performed motions have been introduced. However, these metrics are then influenced by the examiner's opinions, skills, and training making them harder to standardize across patient pools and compare across different prosthetic technologies. Here we aim to objectively quantify the severity of body compensations present in myoelectric prosthetic hand users and evaluate the extent to which traditional objective clinical scores are still able to capture them. METHODS: We have instructed 9 below-elbow prosthesis users and 9 able-bodied participants to complete three established objective clinical tests: Box-and-Blocks-Test, Clothespin-Relocation-Test, and Southampton-Hand-Assessment-Procedure. During all tests, upper-body kinematics has been recorded. RESULTS: While the analysis showed that there are some correlations between the achieved clinical scores and the individual body segment travel distances and average speeds, there were only weak correlations between the clinical scores and the observed ranges of motion. At the same time, the compensations were observed in all prosthesis users and, for the most part, they were substantial across the tests. CONCLUSION: The sole reliance on the currently available objective clinical assessment methods seems inadequate as the compensatory movements are prominent in prosthesis users and yet not sufficiently accounted for.

Upper limb prostheses: bridging the sensory gap.

Replacing human hand function with prostheses goes far beyond only recreating muscle movement with feedforward motor control. Natural sensory feedback is pivotal for fine dexterous control and finding both engineering and surgical solutions to replace this complex biological function is imperative to achieve prosthetic hand function that matches the human hand. This review outlines the nature of the problems underlying sensory restitution, the engineering methods that attempt to address this deficit and the surgical techniques that have been developed to integrate advanced neural interfaces with biological systems. Currently, there is no single solution to restore sensory feedback. Rather, encouraging animal models and early human studies have demonstrated that some elements of sensation can be restored to improve prosthetic control. However, these techniques are limited to highly specialized institutions and much further work is required to reproduce the results achieved, with the goal of increasing availability of advanced closed loop prostheses that allow sensory feedback to inform more precise feedforward control movements and increase functionality.

Surgical treatments for postamputation pain: study protocol for an international, double-blind, randomised controlled trial.

BACKGROUND: Painful conditions such as residual limb pain (RLP) and phantom limb pain (PLP) can manifest after amputation. The mechanisms underlying such postamputation pains are diverse and should be addressed accordingly. Different surgical treatment methods have shown potential for alleviating RLP due to neuroma formation - commonly known as neuroma pain - and to a lesser degree PLP. Two reconstructive surgical interventions, namely targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI), are gaining popularity in postamputation pain treatment with promising results. However, these two methods have not been directly compared in a randomised controlled trial (RCT). Here, we present a study protocol for an international, double-blind, RCT to assess the effectiveness of TMR, RPNI, and a non-reconstructive procedure called neuroma transposition (active control) in alleviating RLP, neuroma pain, and PLP. METHODS: One hundred ten upper and lower limb amputees suffering from RLP will be recruited and assigned randomly to one of the surgical interventions (TMR, RPNI, or neuroma transposition) in an equal allocation ratio. Complete evaluations will be performed during a baseline period prior to the surgical intervention, and follow-ups will be conducted in short term (1, 3, 6, and 12 months post-surgery) and in long term (2 and 4 years post-surgery). After the 12-month follow-up, the study will be unblinded for the evaluator and the participants. If the participant is unsatisfied with the outcome of the treatment at that time, further treatment including one of the other procedures will be discussed in consultation with the clinical investigator at that site. DISCUSSION: A double-blind RCT is necessary for the establishment of evidence-based procedures, hence the motivation for this work. In addition, studies on pain are challenging due to the subjectivity of the experience and the lack of objective evaluation methods. Here, we mitigate this problem by including different pain evaluation methods known to have clinical relevance. We plan to analyse the primary variable, mean change in NRS (0-10) between baseline and the 12-month follow-up, using the intention-to-treat (ITT) approach to minimise bias and keep the advantage of randomisation. The secondary outcomes will be analysed on both ITT and per-protocol (PP). An adherence protocol (PP population) analysis will be used for estimating a more realistic effect of treatment. TRIAL REGISTRATION: ClincialTrials.gov NCT05009394.

A Haptic Sleeve as a Method of Mechanotactile Feedback Restoration for Myoelectric Hand Prosthesis Users.

Current myoelectric upper limb prostheses do not restore sensory feedback, impairing fine motor control. Mechanotactile feedback restoration with a haptic sleeve may rectify this problem. This randomised crossover within-participant controlled study aimed to assess a prototype haptic sleeve's effect on routine grasping tasks performed by eight able-bodied participants. Each participant completed 15 repetitions of the three tasks: Task 1-normal grasp, Task 2-strong grasp and Task 3-weak grasp, using visual, haptic, or combined feedback All data were collected in April 2021 in the Scottish Microelectronics Centre, Edinburgh, UK. Combined feedback correlated with significantly higher grasp success rates compared to the vision alone in Task 1 (p < 0.0001), Task 2 (p = 0.0057), and Task 3 (p = 0.0170). Similarly, haptic feedback was associated with significantly higher grasp success rates compared to vision in Task 1 (p < 0.0001) and Task 2 (p = 0.0015). Combined feedback correlated with significantly lower energy expenditure compared to visual feedback in Task 1 (p < 0.0001) and Task 3 (p = 0.0003). Likewise, haptic feedback was associated with significantly lower energy expenditure compared to the visual feedback in Task 1 (p < 0.0001), Task 2 (p < 0.0001), and Task 3 (p < 0.0001). These results suggest that mechanotactile feedback provided by the haptic sleeve effectively augments grasping and reduces its energy expenditure.

Personalised 3D printed respirators for healthcare workers during the COVID-19 pandemic.

Widespread issues in respirator availability and fit have been rendered acutely apparent by the COVID-19 pandemic. This study sought to determine whether personalized 3D printed respirators provide adequate filtration and function for healthcare workers through a Randomized Controlled Trial (RCT). Fifty healthcare workers recruited within NHS Lothian, Scotland, underwent 3D facial scanning or 3D photographic reconstruction to produce 3D printed personalized respirators. The primary outcome measure was quantitative fit-testing to FFP3 standard. Secondary measures included respirator comfort, wearing experience, and function instrument (R-COMFI) for tolerability, Modified Rhyme Test (MRT) for intelligibility, and viral decontamination on respirator material. Of the 50 participants, 44 passed the fit test with the customized respirator, not significantly different from the 38 with the control (p = 0.21). The customized respirator had significantly improved comfort over the control respirator in both simulated clinical conditions (p < 0.0001) and during longer wear (p < 0.0001). For speech intelligibility, both respirators performed equally. Standard NHS decontamination agents were able to eradicate 99.9% of viral infectivity from the 3D printed plastics tested. Personalized 3D printed respirators performed to the same level as control disposable FFP3 respirators, with clear communication and with increased comfort, wearing experience, and function. The materials used were easily decontaminated of viral infectivity and would be applicable for sustainable and reusable respirators.

Comparison of Patient Satisfaction on a Day-case Mastectomy Pathway for Breast Cancer Versus a Traditional Inpatient Delivery Model, Using a Validated Questionnaire.

BACKGROUND: In 2011, a guidance was issued by the National Health Service (NHS) Improvement a model on how mastectomy could be offered in the day-case setting. The goal of this guidance was to reduce inpatient bed days and cost to the NHS, and demonstrate that it can be performed within an acceptable safety profile. The aim of this study was to assess whether patients find the day-case pathway for mastectomy an acceptable management model. We compared complication rates between the day-case and inpatient delivery model. PATIENTS AND METHODS: This study was a retrospective analysis of patients' experience undergoing day-case (n=26) and inpatient mastectomy (n=60). The primary outcome measure was based on a telephone interview using a validated, standardised questionnaire. RESULTS: No statistically significant difference in the satisfaction levels between the two groups (raw scores 6.76 day-case vs. 6.15 inpatient, p=0.37) was demonstrated. We found no statistically significant difference between the two groups when specifically analysing whether patients found the first night harder as a day-case or inpatient (3.192 vs. 2.80, p=0.59, range 0-10). Our overall complications were 11.4% (day-case) and 18.3% (inpatients). Rates were comparable between the two groups and equivalent to published rates in the literature. CONCLUSION: There was no statistically significant difference in satisfaction scores between patients who had a mastectomy as an inpatient versus those who had their operation as a day-case procedure. In addition, there were no significant differences in the complication rates between the two groups. We conclude then that it is feasible and safe to offer day-case mastectomy, with no loss in patient satisfaction.

Outcomes, Challenges, and Pitfalls after Targeted Muscle Reinnervation in High-Level Amputees: Is It Worth the Effort?

BACKGROUND: Although the distal targets have been lost in proximal upper limb amputees, the neural signals for intuitive hand and arm function are still available and thus can be incorporated into more useful prosthetic function using targeted muscle reinnervation technique. In this article, the authors present their outcomes and range of indications in addition to experiences and pitfalls after 30 targeted muscle reinnervation cases at above-elbow and shoulder disarticulation level of amputation. METHODS: Thirty patients with above-elbow or shoulder disarticulation amputations were enrolled between 2012 and 2017. Indications for targeted muscle reinnervation surgery differed between improvement of prosthetic function (n = 19) and/or pain (n = 11). Functional outcome was evaluated with the Action Research Arm Test, the Southampton Hand Assessment Procedure, and the Clothespin-Relocation Test. Functional evaluation was performed at least at 6 months after final prosthetic fitting. RESULTS: All nerve transfers were successful and provided independent myoelectric signals. The 10 patients available for final functional evaluation showed Action Research Arm Test scores of 20.4 ± 1.9 and Southampton Hand Assessment Procedure scores of 40.5 ± 8.1. The Clothespin-Relocation Test showed a mean time of 34.3 ± 14.4 seconds. CONCLUSIONS: Targeted muscle reinnervation has improved prosthetic control and revolutionized neuroma treatment in upper limb amputees. Still, the rate of abandonment even after targeted muscle reinnervation surgery has been shown high, and several advances within the biotechnological interface will be needed to improve prosthetic function and acceptance in these patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Functional Outcome Scores With Standard Myoelectric Prostheses in Below-Elbow Amputees.

OBJECTIVE: The aim of the study was to report normative outcome data of prosthetic hand function in below-elbow amputees using four different objective measurements closely related to activities of daily living. DESIGN: Seventeen patients who underwent prosthetic fitting after unilateral below-elbow amputation were enrolled in this study. Global upper extremity function was evaluated using the Action Research Arm Test, Southampton Hand Assessment Procedure, the Clothespin-Relocation Test, and the Box and Block Test, which monitor hand and extremity function. RESULTS: The patients achieved a mean ± SD Action Research Arm Test score of 35.06 ± 4.42 of 57. The mean ± SD Southampton Hand Assessment Procedure score was 65.12 ± 13.95 points. The mean ± SD time for the Clothespin-Relocation Test was 22.57 ± 7.50 secs, and the mean ± SD score in the Box and Block Test was 20.90 ± 5.74. CONCLUSIONS: In the current economic situation of health care systems, demonstrating the effectiveness and necessity of rehabilitation interventions is of major importance. This study reports outcome data of below-elbow amputees and provides a useful guide for expected prosthetic user performance.

Attachment of upper arm prostheses with a subcutaneous osseointegrated implant in transhumeral amputees.

BACKGROUND: The stump-socket interface is of utmost importance for prosthetic function in transhumeral amputees. Stability of this connection may be improved using a newly designed subcutaneous implant. OBJECTIVES: The purpose was to determine the effect of the implant together with customized socket designs on the range of motion of the shoulder and the prosthetic function compared to conventional fitting. STUDY DESIGN: Case series. METHODS: The range of motion was measured with scaled metrics and the prosthetic function evaluated with the Southampton Hand Assessment Procedure and the Box and Block Test. Maximal loading was measured in straight and 90° flexion of the elbow. RESULTS: The restriction of range of motion after conventional fitting was decreased from 42.55% ± 6.56% to 9.23% ± 14.89% in Patient I and from 62.18% ± 15.19% to 2.51% ± 2.49% in Patient II using the implant with customized sockets compared to range of motion without prosthesis. Both patients showed improved prosthetic function with the new system compared to conventional fitting. CONCLUSION: The presented subcutaneous humeral implant, together with customized socket designs without straps and harnesses to the contralateral shoulder, can maintain almost complete range of motion of the shoulder. This resulted in improved prosthetic function and comfort for the patient without constant risk of infection. Clinical relevance Discomfort and limited prosthetic function are the main reasons for abandonment especially in transhumeral amputees. Shoulder straps and harnesses within conventional socket designs may not only lead to pain and skin irritations at the contralateral shoulder but also limit the range of motion of the shoulder joint and therefore prosthetic function.

Translating Research on Myoelectric Control into Clinics-Are the Performance Assessment Methods Adequate?

Missing an upper limb dramatically impairs daily-life activities. Efforts in overcoming the issues arising from this disability have been made in both academia and industry, although their clinical outcome is still limited. Translation of prosthetic research into clinics has been challenging because of the difficulties in meeting the necessary requirements of the market. In this perspective article, we suggest that one relevant factor determining the relatively small clinical impact of myocontrol algorithms for upper limb prostheses is the limit of commonly used laboratory performance metrics. The laboratory conditions, in which the majority of the solutions are being evaluated, fail to sufficiently replicate real-life challenges. We qualitatively support this argument with representative data from seven transradial amputees. Their ability to control a myoelectric prosthesis was tested by measuring the accuracy of offline EMG signal classification, as a typical laboratory performance metrics, as well as by clinical scores when performing standard tests of daily living. Despite all subjects reaching relatively high classification accuracy offline, their clinical scores varied greatly and were not strongly predicted by classification accuracy. We therefore support the suggestion to test myocontrol systems using clinical tests on amputees, fully fitted with sockets and prostheses highly resembling the systems they would use in daily living, as evaluation benchmark. Agreement on this level of testing for systems developed in research laboratories would facilitate clinically relevant progresses in this field.

Fascicular shifting: a novel technique to overcome large nerve defects.

OBJECTIVE Over the last decade, a number of authors have investigated the utility of different biological and synthetic matrices as alternatives to conventional nerve grafts. However, the autologous nerve graft remains the gold standard, even though it often involves using a pure sensory nerve to reconstruct a mixed or even a pure motor nerve. Furthermore, limited donor sites often necessitate a significant mismatch of needed nerve tissue, especially for large proximal nerve defects such as brachial plexus lesions. Here, the authors present a new technique that overcomes these problems: the fascicular shift procedure (FSP). A fascicular group of the nerve distal to the injury is harvested in a sufficient length to bridge the nerve defect. METHODS The method of fascicular shifting was tested at the sciatic nerve in 45 Lewis rats. In the experimental group, a 15-mm nerve defect was created and reconstructed with a fascicular group that was harvested directly distal to the gap. This group was compared with 1 negative control group (defect without reconstruction) and 3 positive control groups (sensory, motor, and mixed graft). After 12 weeks of nerve regeneration, outcome was evaluated using retrograde labeling, histomorphometric analysis, and muscle force analysis. RESULTS All reconstructed groups showed successful regeneration with various levels of function. The negative control group showed minimal force measurements that were of no functional value. The fascicular shift provided sufficient guidance to overcome nerve defects, had higher (p < 0.1) motor neuron counts (1958.75 ± 657.21) than the sensory graft (1263.50 ± 538.90), and was equal to motor grafts (1490.43 ± 794.80) and mixed grafts (1720.00 ± 866.421). This tendency of improved motor regeneration was confirmed in all analyses. The mixed graft group was compared with the experimental group to investigate the influence of the potential damage induced by the fascicular shift distal to the repair site. However, none of the analyses revealed an impairment of nerve regeneration for both the tibial and common peroneal index muscles. CONCLUSIONS This study demonstrates that harvesting a transplant from the nerve segment distal to the injury site offers a mixed graft without causing additional donor-site morbidity. These grafts perform statistically better than a standard sensory graft in terms of motor recovery. The fascicular shift presents a novel method to reconstruct large proximal nerve defects, making it immensely attractive in brachial plexus reconstruction.

Context-Dependent Upper Limb Prosthesis Control for Natural and Robust Use.

Pattern recognition and regression methods applied to the surface EMG have been used for estimating the user intended motor tasks across multiple degrees of freedom (DOF), for prosthetic control. While these methods are effective in several conditions, they are still characterized by some shortcomings. In this study we propose a methodology that combines these two approaches for mutually alleviating their limitations. This resulted in a control method capable of context-dependent movement estimation that switched automatically between sequential (one DOF at a time) or simultaneous (multiple DOF) prosthesis control, based on an online estimation of signal dimensionality. The proposed method was evaluated in scenarios close to real-life situations, with the control of a physical prosthesis in applied tasks of varying difficulties. Test prostheses were individually manufactured for both able-bodied and transradial amputee subjects. With these prostheses, two amputees performed the Southampton Hand Assessment Procedure test with scores of 58 and 71 points. The five able-bodied individuals performed standardized tests, such as the box&block and clothes pin test, reducing the completion times by up to 30%, with respect to using a state-of-the-art pure sequential control algorithm. Apart from facilitating fast simultaneous movements, the proposed control scheme was also more intuitive to use, since human movements are predominated by simultaneous activations across joints. The proposed method thus represents a significant step towards intelligent, intuitive and natural control of upper limb prostheses.