Excitation of natural spinal reflex loops in the sensory-motor control of hand prostheses.

Sensory feedback for prosthesis control is typically based on encoding sensory information in specific types of sensory stimuli that the users interpret to adjust the control of the prosthesis. However, in physiological conditions, the afferent feedback received from peripheral nerves is not only processed consciously but also modulates spinal reflex loops that contribute to the neural information driving muscles. Spinal pathways are relevant for sensory-motor integration, but they are commonly not leveraged for prosthesis control. We propose an approach to improve sensory-motor integration for prosthesis control based on modulating the excitability of spinal circuits through the vibration of tendons in a closed loop with muscle activity. We measured muscle signals in healthy participants and amputees during different motor tasks, and we closed the loop by applying vibration on tendons connected to the muscles, which modulated the excitability of motor neurons. The control signals to the prosthesis were thus the combination of voluntary control and additional spinal reflex inputs induced by tendon vibration. Results showed that closed-loop tendon vibration was able to modulate the neural drive to the muscles. When closed-loop tendon vibration was used, participants could achieve similar or better control performance in interfaces using muscle activation than without stimulation. Stimulation could even improve prosthetic grasping in amputees. Overall, our results indicate that closed-loop tendon vibration can integrate spinal reflex pathways in the myocontrol system and open the possibility of incorporating natural feedback loops in prosthesis control.

Long-term functional and clinical outcome of combined targeted muscle reinnervation and osseointegration for functional bionic reconstruction in transhumeral amputees: a case series.

OBJECTIVE: To describe and evaluate the combination of osseointegration and nerve transfers in 3 transhumeral amputees. DESIGN: Case series. PATIENTS: Three male patients with a unilateral traumatic transhumeral amputation. METHODS: Patients received a combination of osseointegration and targeted muscle reinnervation surgery. Rehabilitation included graded weight training, range of motion exercises, biofeedback, table-top prosthesis training, and controlling the actual device. The impairment in daily life, health-related quality of life, and pain before and after the intervention was evaluated in these patients. Their shoulder range of motion, prosthesis embodiment, and function were documented at a 2- to 5-year follow-up. RESULTS: All 3 patients attended rehabilitation and used their myoelectric prosthesis on a daily basis. Two patients had full shoulder range of motion with the prosthesis, while the other patient had 55° of abduction and 45° of anteversion. They became more independent in their daily life activities after the intervention and incorporated their prosthesis into their body scheme to a high extent. CONCLUSION: These results indicate that patients can benefit from the combined procedure. However, the patients' perspective, risks of the surgical procedures, and the relatively long rehabilitation procedure need to be incorporated in the decision-making.

[Prosthetic Fitting Concepts after Major Amputation in the Upper Limb - an Overview of Current Possibilities]. / Prothetische Versorgungskonzepte nach Majoramputation der oberen Extremität ­ eine Übersicht gegenwärtiger Möglichkeiten.

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.

Life outcomes after paediatric kidney transplantation: a qualitative, biographical study in long-term survivors.

OBJECTIVE: The objective of this study was to analyse the narrative life stories of children with end-stage kidney disease (ESKD) and their families to determine how health professionals can effectively support these children to achieve better life outcomes. DESIGN: Qualitative narrative biographic study. SETTING: We invited every long-term survivor of paediatric kidney transplants and their families at the Medical University of Vienna between 2008 and 2013 to participate in this study. PARTICIPANTS: Nineteen patients (women: n=8, 42%) and 34 family members (women: n=22, 65%) were interviewed. The patients had a mean age of 7.6 (SD±5.6) years at the time of transplantation and 22.2 (SD±5.4) at the time of interview. MAIN OUTCOMES MEASURES: A qualitative narrative biographical analysis was combined with computational structured topic models using the Latent Dirichlet Allocation. RESULTS: The overarching finding was the desire for normality in daily life in long-term survivors and their families but with different perceptions of what normality looks like and predominance of this aspect evolving. Different strategies were used by patients (focused on their advancement) and caregivers (normality for all family members). Siblings played a major role in supporting survivors' social inclusion. CONCLUSIONS: The strong desire for normality confirms recent findings of the Standardised Outcomes in Nephrology Group initiative, which proposes survival and life participation as core outcomes in children with chronic kidney disease. Our study should be a starting point for an international effort to identify typologies and stratified interventions for children with ESKD and their families, particularly siblings.

Nerve transfer reversal to treat co-contraction after anatomic brachial plexus reconstruction and Oberlin transfer: A case report.

Distal nerve transfers to restore elbow flexion have become standard of care in brachial plexus reconstruction. The purpose of this report is to draw attention to intractable co-contraction as a rare but significant adverse event of distal nerve transfers. Here we report of treatment of a disabling co-contraction of the brachialis muscle and wrist/finger flexors after median to brachialis fascicular transfer in a 61-year-old male patient. The primary injury was an postganglionic lesion of roots C5/C6 and a preganglionic injury of C7/C8 with intact root Th1 after a motor bicycle accident. After upper brachial plexus reconstruction (C5/C6 to suprascapular nerve and superior trunk) active mobility in the shoulder joint (supraspinatus, deltoid) could be restored. However, due to lacking motor recovery of elbow flexion the patient underwent additional median to brachialis nerve transfer. Shortly after, active elbow flexion commenced with rapid recovery to M4 at 9 months postoperatively. However, despite intensive EMG triggered physiotherapy the patient could not dissociate hand from elbow function and was debilitated by this iatrogenic co-contraction. After preoperative ultrasound-guided block resulted in preserved biceps function, the previously transferred median nerve fascicle was reversed. This was done by dissecting the previous nerve transfer of the median nerve fascicle to the brachialis muscle branch and adapting the fascicles to their original nerve. Postoperatively, the patient was followed up for 10 months without a complication and maintained M4 elbow flexion with independent strong finger flexion. Distal nerve transfers are an excellent option to restore function, however, in some patients cognitive limitations may prevent cortical reorganization and lead to disturbing co-contractions.

Nerve Transfers for Brachial Plexus Reconstruction in Patients over 60 Years.

Negative expectations regarding nerve reconstruction in the elderly prevail in the literature, but little is known about the effectiveness of nerve transfers in patients with brachial plexus injuries aged over 60 years. We present a series of five patients (1 female, 4 male) aged between 60 and 81 years (median 62.0 years) who underwent nerve reconstruction using multiple nerve transfers in brachial plexopathies. The etiology of brachial plexus injury was trauma (n = 2), or iatrogenic, secondary to spinal surgical laminectomy, tumor excision and radiation for breast cancer (n = 3). All but one patient underwent a one-stage reconstruction including neurolysis and extra-anatomical nerve transfer alone (n = 2) or combined with anatomical reconstruction by sural nerve grafts (n = 2). One patient underwent a two-stage reconstruction, which involved a first stage anatomical brachial plexus reconstruction followed by a second stage nerve transfer. Neurotizations were performed as double (n = 3), triple (n = 1) or quadruple (n = 1) nerve or fascicular transfers. Overall, at least one year postoperatively, successful results, characterized by a muscle strength of M3 or more, were restored in all cases, two patients even achieving M4 grading in the elbow flexion. This patient series challenges the widely held dogma that brachial plexus reconstruction in older patients will produce poor outcomes. Distal nerve transfers are advantageous as they shorten the reinnervation distance. Healthy, more elderly patients should be judiciously offered the whole spectrum of reconstructive methods and postoperative rehabilitation concepts to regain useful arm and hand function and thus preserve independence after a traumatic or nontraumatic brachial plexus injury.

Therapy Interventions for Upper Limb Amputees Undergoing Selective Nerve Transfers.

Targeted Muscle Reinnervation (TMR) improves the biological control interface for myoelectric prostheses after above-elbow amputation. Selective activation of muscle units is made possible by surgically re-routing nerves, yielding a high number of independent myoelectric control signals. However, this intervention requires careful patient selection and specific rehabilitation therapy. Here a rehabilitation protocol is presented for high-level upper limb amputees undergoing TMR, based on an expert Delphi study. Interventions before surgery include detailed patient assessment and general measures for pain control, muscle endurance and strength, balance, and range of motion of the remaining joints. After surgery, additional therapeutic interventions focus on edema control and scar treatment and the selective activation of cortical areas responsible for upper limb control. Following successful reinnervation of target muscles, surface electromyographic (sEMG) biofeedback is used to train the activation of the novel muscular units. Later on, a table-top prosthesis may provide the first experience of prosthetic control. After fitting the actual prosthesis, training includes repetitive drills without objects, object manipulation, and finally, activities of daily living. Ultimately, regular patient appointments and functional assessments allow tracking prosthetic function and enabling early interventions if malfunctioning.

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

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.

Case Report: Bionic Reconstruction in an Adult With Obstetric Brachial Plexus Injury.

Introduction: Many adults who had a severe Narakas IV obstetric brachial plexus injury (OBPI) suffer from extensive impairments in daily living due to limited hand-arm function. The dramatic loss of axonal support at this very early age of development often render the entire extremity a biologic wasteland and reconstructive methods and therapies often fail to recover any functional hand use. In this scenario bionic reconstruction, including an elective amputation and a subsequent prosthetic fitting, may enable functional improvement in adults suffering from the consequences of such severe brachial plexus injuries. We here describe our experience in treating such patients and lay out the surgical rational and rehabilitation protocol exemplified in one patient. Case Presentation/Methods: A 27-year-old adult with a unilateral OBPI contacted our center. He presented with globally diminished function of the affected upper extremity with minimal hand activity, resulting in an inability to perform various tasks of daily living. No biological reconstructive efforts were available to restore meaningful hand function. An interdisciplinary evaluation, including a psychosocial assessment, was used to assess eligibility for bionic reconstruction. Before the amputation and after the prosthetic fitting functional assessments and self-reported questionnaires were performed. Results: One month after the amputation and de-rotation osteotomy of the humerus the patient was fitted with a myoelectric prosthesis. At the 1.5 year-follow-up assessment, the patient presented with a distinct improvement of function: the ARAT improved from 12 to 20 points, SHAP score improved from 8 to 29, and the DASH value improved from 50 to 11.7. The average wearing times of the prosthesis were 5 to 6 h per day (on 4-5 days a week). Discussion: The options for adults suffering from the consequences of severe OBPIs to improve function are limited. In selected patients in whom the neurological deficit is so severe that biologic hand function is unsatisfactory, an elective amputation and subsequent restoration of the hand with mechatronic means may be an option. The follow-up results indicate that this concept can indeed lead to solid hand function and independence in daily activities after amputation, subsequent prosthetic fitting, and rehabilitation.

Outcomes research in non-specific low back pain : Knowledge transfer in clinical practice.

OBJECTIVE: The aims of this article are to provide an overview and discuss current concepts and future trends in outcomes research in non-specific low back pain, specifically considering the perspective of patients, patient-reported outcomes and outcome measures as well as to facilitate knowledge transfer into clinical practice. REVIEW STRATEGY: The breadth of this work and the required brevity of this article were not amenable to a formal approach, such as a systematic literature review or a formal scoping review. Literature sources were identified through medical databases but different sources of information and of various methodologies were also included. Furthermore, outcomes meaningful for patients and examples of outcome measures that are applicable in clinical practice were extracted. Areas for future research were identified and discussed. RESULTS: Patient-reported outcomes and outcome measures are essential in patient-centered care. The assessment of the patients' perspective is important to ensure motivation, active involvement, self-management and adherence, especially in non-pharmacological interventions for low back pain. To facilitate the use of outcome measurements for low back pain in clinical practice, future studies should focus on a clinically feasible index, which includes patient-reported as well as clinician-reported or performance-based variables. Relationships between different types of outcomes and outcome measures as well as resource and outcome-based healthcare constitute important topics for future research. New digital technologies can support continuous outcome measurement and might enable new patient-driven models of care. CONCLUSION: Active patient involvement is an essential part of non-pharmacological treatment in low back pain and needs to be considered in terms of outcomes and outcome measurement.