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.

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.

[Spasticity-correcting surgery can have long-lasting effects]. / Spasticitetskorrigerande kirurgi kan ge långvariga förbättringar.

Spasticity is a common secondary complication after injuries to the central nervous system (CNS). Spasticity may severely impair arm and hand function, and consequently, affect an individual's function, resulting in disabilities or limiting activities and participation. Today, there is conflicting evidence regarding the effectiveness of available spasticity treatments. The population of adults with spasticity problems due to a CNS injury is heterogenic. A multidisciplinary approach is essential in customizing treatment to individual needs. The planning of treatment should consider the remaining upper limb functions and the patient's potential to improveme. Spasticity-correcting surgery is an option that seems underutilized. This article describes a structured and standardized program for the preoperative assessment, the surgical technique and the postoperative rehabilitation of patients undergoing upper limb spasticity-correcting surgery.

Feasibility of using fNIRS to explore motor-related regional haemodynamic signal changes in patients with sensorimotor impairment and healthy controls: A pilot study.

BACKGROUND: While functional near-infrared spectroscopy (fNIRS) can provide insight into cortical brain activity during motor tasks in healthy and diseased populations, the feasibility of using fNIRS to assess haemoglobin-evoked responses to reanimated upper limb motor function in patients with tetraplegia remains unknown. OBJECTIVE: The primary objective of this pilot study is to determine the feasibility of using fNIRS to assess cortical signal intensity changes during upper limb motor tasks in individuals with surgically restored grip functions. The secondary objectives are: 1) to collect pilot data on individuals with tetraplegia to determine any trends in the cortical signal intensity changes as measured by fNIRS and 2) to compare cortical signal intensity changes in affected individuals versus age-appropriate healthy volunteers. Specifically, patients presented with tetraplegia, a type of paralysis resulting from a cervical spinal cord injury causing loss of movement and sensation in both lower and upper limbs. All patients have their grip functions restored by surgical tendon transfer, a procedure which constitutes a unique, focused stimulus for brain plasticity. METHOD: fNIRS is used to assess changes in cortical signal intensity during the performance of two motor tasks (isometric elbow and thumb flexion). Six individuals with tetraplegia and six healthy controls participate in the study. A block paradigm is utilized to assess contralateral and ipsilateral haemodynamic responses in the premotor cortex (PMC) and primary motor cortex (M1). We assess the amplitude of the optical signal and spatial features during the paradigms. The accuracy of channel locations is maximized through 3D digitizations of channel locations and co-registering these locations to template atlas brains. A general linear model approach, with short-separation regression, is used to extract haemodynamic response functions at the individual and group levels. RESULTS: Peak oxyhaemoglobin (oxy-Hb) changes in PMC appear to be particularly bilateral in nature in the tetraplegia group during both pinch and elbow trials whereas for controls, a bilateral PMC response is not especially evident. In M1 / primary sensory cortex (S1), the oxy-Hb responses to the pinch task are mainly contralateral in both groups, while for the elbow flexion task, lateralization is not particularly clear. CONCLUSIONS: This pilot study shows that the experimental setup is feasible for assessing brain activation using fNIRS during volitional upper limb motor tasks in individuals with surgically restored grip functions. Cortical signal changes in brain regions associated with upper extremity sensorimotor processing appear to be larger and more bilateral in nature in the tetraplegia group than in the control group. The bilateral hemispheric response in the tetraplegia group may reflect a signature of adaptive brain plasticity mechanisms. Larger studies than this one are needed to confirm these findings and draw reliable conclusions.

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.

Technique and biomechanical properties of the side-to-side Z-lengthening in spasticity-correcting surgery- a study on porcine tendons.

Spasticity-correcting surgery in patients with injuries to upper motor neurons include various techniques, including tenotomies and lengthening of tendons of spastic muscles. Early mobilization including active loading of a lengthened tendon is essential to prevent adhesion formation, which necessitates a lengthening technique that resists the forces produced by the involved muscles. This study on animal tendons reports the biomechanical properties in regards to elongation and load to failure in porcine tendons lengthened by either a 3 or 5 cm overlap and tested in a simple force rig. The lengthening technique used in these tendons is described in step-by-step detail. The mean elongation of 20 lengthened tendons at 100 N was 10 mm for tendons with a 3 cm overlap and 6 mm for tendons with a 5 cm overlap. The mean peak load at failure of the construct was 138 N for lenghened tendons with a 3 cm overlap and 201 N for tendons with a 5 cm overlap. The results of this study indicate that a tendon lengthened by the described technique with a mere overlap of three cm will withstand the estimated forces elicited by muscles in the forearm immediately after surgery.

Linking Prioritized Occupational Performance in Patients Undergoing Spasticity-Correcting Upper Limb Surgery to the International Classification of Functioning, Disability, and Health.

Background: Spasticity is generally caused by damage to the spinal cord or the areas of the brain that controls movements, which poses significant limitations in occupational tasks. Objectives: The aims of the study were to (I) describe prioritized occupational performance problems (POPP) among patients who underwent upper limb spasticity-correcting surgery and map them to the International Classification of Function, Disability, and Health (ICF); (II) assess outcomes postsurgery; (III) assess whether the results are influenced by the diagnosis, gender, and residual muscle function; and (IV) assess correlation between changes in COPM and gains in grasp ability and grip strength. Methods: In this retrospective study, assessments occurred pre- and postsurgery, including the Canadian Occupational Performance Measure (COPM), grip strength, and grasp ability. POPP were transformed to prioritized occupational performance goals (POPG) during subsequent rehabilitation. Results: 60 patients with a history of spinal cord injury (SCI) (n = 42; 59%), stroke (n = 25; 34%), traumatic brain injury (TBI) (n = 4; 6%), and reason unknown (n = 1; 1%) were included, with a mean age of 57 (±13) years. Of those, 11 had bilateral surgery, generating 71 COPM forms and 320 POPG. The POPG were mapped to the ICF activity and participation chapter, most often to self-care (n = 131; 41%), domestic life (n = 68; 21%), and mobility (n = 58; 18%). COPM scores were significantly increased postsurgery, irrespective of diagnosis, gender, and muscle function. No clear correlation between COPM improvement and hand function gains was shown. Conclusion: Patients who underwent spasticity-correcting upper limb surgery identified difficulties with a wide range of occupational tasks that they considered as important to regain. Treatment-induced gains in occupational performance were significant but had no clear correlation with gains in grasp ability and hand strength. Independent of diagnosis, gender, and residual muscle function, it seems important to address the activity- and participation-specific aspects in the assessment and rehabilitation of patients.

[The combination of nerve and tendon transfers offers good possibilities for hand function in patients with cervical spinal cord injury]. / Så kan funktion i hand och arm återfås efter halsryggmärgsskada.

Regaining upper extremity function is a prioritized matter for patients with tetraplegia after a cervical spinal cord injury (cSCI). The purpose of this article is to describe the current evidence and treatment strategies for upper extremity reconstruction after cSCI at the Centre for Advanced Reconstruction of Extremities, Sahlgrenska University Hospital, Sweden. The specialized unit works in a multidisciplinary setting to optimize the care of the patient population. Preoperative planning and an individualized treatment according to the needs and abilities of the patient are considered key points to achieve the best possible outcome. The addition of nerve transfers to the established method of tendon transfers for grip reconstruction has led to increased possibilities to achieve both functional hand opening and grip. Here we present our preferred method of upper extremity reconstruction, which involves a two-staged procedure where the tendon-based grip reconstruction is preceded by nerve transfer of the supinator to posterior intraosseous nerve whenever possible. Important clinical aspects as well as future perspectives are discussed.

Functional outcomes of spasticity-reducing surgery and rehabilitation at 1-year follow-up in 30 patients.

The effects of spasticity-reducing surgery in the upper extremity were assessed in a prospective observational study of 30 consecutive patients with stroke (n = 13), incomplete spinal cord injury (n = 9), traumatic brain injury (n = 5), cerebral palsy (n = 2), and degenerative central nervous system disease (n = 1). Surgery, which included lengthening of tendons and release of muscles, was followed by early rehabilitation at three intensity levels depending on the patients' specific needs and conditions. At 12 months follow-up there were significant improvements in all outcome measures with the following mean values: spasticity decreased by 1.4 points (Modified Ashworth Scale, 0-5), visual analogue pain score by 1.3 points, and both Canadian Occupational Performance Measures increased (performance by 3.4 and satisfaction by 3.6), and most measures of joint position or mobility improved. Hand surgery combined with early and comprehensive rehabilitation improves function, activity and patients' satisfaction in patients with disabling spasticity with improvement lasting for at least 1 year.Level of evidence: II.

A 15-year follow-up of transfemoral amputees with bone-anchored transcutaneous prostheses.

AIMS: The aim of this study was to describe implant and patient-reported outcome in patients with a unilateral transfemoral amputation (TFA) treated with a bone-anchored, transcutaneous prosthesis. METHODS: In this cohort study, all patients with a unilateral TFA treated with the Osseointegrated Prostheses for the Rehabilitation of Amputees (OPRA) implant system in Sahlgrenska University Hospital, Gothenburg, Sweden, between January 1999 and December 2017 were included. The cohort comprised 111 patients (78 male (70%)), with a mean age 45 years (17 to 70). The main reason for amputation was trauma in 75 (68%) and tumours in 23 (21%). Patients answered the Questionnaire for Persons with Transfemoral Amputation (Q-TFA) before treatment and at two, five, seven, ten, and 15 years' follow-up. A prosthetic activity grade was assigned to each patient at each timepoint. All mechanical complications, defined as fracture, bending, or wear to any part of the implant system resulting in removal or change, were recorded. RESULTS: The Q-TFA scores at two, five, seven, and ten years showed significantly more prosthetic use, better mobility, fewer problems, and an improved global situation, compared with baseline. The survival rate of the osseointegrated implant part (the fixture) was 89% and 72% after seven and 15 years, respectively. A total of 61 patients (55%) had mechanical complications (mean 3.3 (SD 5.76)), resulting in exchange of the percutaneous implant parts. There was a positive relationship between a higher activity grade and the number of mechanical complications. CONCLUSION: Compared with before treatment, the patient-reported outcome was significantly better and remained so over time. Although osseointegration and the ability to transfer loads over a 15-year period have been demonstrated, a large number of mechanical failures in the external implant parts were found. Since these were related to higher activity, restrictions in activity and improvements to the mechanical properties of the implant system are required. Cite this article: Bone Joint J 2020;102-B(1):55-63.

Activity gains after upper limb surgery for spasticity in patients with spinal cord injury.

Spasticity is a common and increasingly prevalent secondary complication of spinal cord injury. The aim of the study was to evaluate patient-experienced gains in prioritized activities after surgery to reduce the effects of spasticity in upper limbs in tetraplegia. The study includes evaluation of 30 operations for 27 patients performed on hypertonic tetraplegic hands during 2007-2015 using the Canadian Occupational Performance Measure. Activity performance increased at both 6 months and 12 months by a mean of 3.0 and 2.9 points, respectively. Satisfaction increased by 3.3 and 3.4, respectively. All types of activities improved, with wheelchair manoeuvring as one of the highest rated. The intervention increased prioritized activity performance and persisted at least 12 months after surgery. Patients with mild upper limb impairment showed greater improvement after surgery. After operation, patients were able to perform 71% of their prioritized activities, which they could not perform before. Patients' satisfaction with the performance was high. LEVEL OF EVIDENCE: IV.

Upper extremity reconstruction in non-traumatic spinal cord injuries: An under-recognized opportunity.

OBJECTIVE: This study reviews the usefulness of surgical improvement of arm and hand function in patients with non-traumatic spinal cord injury who differ significantly from individuals with post-traumatic tetraplegia with respect to age, injury pattern, gender and socio-economic factors. DESIGN: Case series. Tests were conducted preoperatively and 12 months postoperatively. PATIENTS: The results of 14 upper extremity reconstructions in 11 patients (7 women, 4 men) with spinal cord injury, mean age at injury 49 years (standard deviation (SD) 12), were reviewed. METHODS: Key pinch strength, grip strength and first web space opening were recorded pre- and post-operatively in all patients, 5 patients (7 hands) were evaluated prospectively regarding manual dexterity. RESULTS: All parameters were significantly improved. Strength of key pinch increased from 0.3 kg in 1 case and zero in 10 cases to a mean of 1.6 kg (SD 0.9). Mean grip strength increased from 0 to 3.2 kg (SD 4.5). Maximal distance between thumb and index increased from 2.1 cm (SD 4.1) to 6.4 cm (SD 4.4). Manual dexterity increased. CONCLUSION: Individuals with stable non-traumatic tetraplegia benefit from surgical rehabilitation of their upper extremities. The number of non-traumatic spinal cord injuries is likely to increase as lifespan increases worldwide, and further research into the functional rehabilitation of this population will therefore become increasingly relevant.

The extensor pollicis longus-loop-knot (ELK) procedure for dynamic balance of the paralyzed thumb interphalangeal joint.

Hyperflexion of the thumb interphalangeal (IP) joint interferes significantly with pinching between the thumb and the index finger in a paralyzed hand. The extensor pollicis longus-loop-knot (ELK) procedure was used successfully in 7 tetraplegic patients to balance the IP joint between strong restored flexor function and lacking or weak antagonism of the thumb extensors. A V-shaped incision was made over the extensor hood at the level of the IP joint, the extensor pollicis longus (EPL) tendon was elevated, a loop was formed, secured by sutures, and then turned proximally onto the EPL tendon itself and fixed on both sides. The operation reliably limited the maximum range of IP flexion at 20 to 30 degrees from neutral. Postoperative problems did not occur. The ELK procedure is easy and quick and secures the optimal setting of IP flexion with limited flexibility, which is advantageous compared with rigid bony arthrodesis. It also avoids certain disadvantages of the commonly used flexor pollicis longus split tenodesis and is therefore a valuable alternative for the correction of Froment's sign due to intrinsic or extrinsic paralysis of the thumb.

Outcomes of single-stage grip-release reconstruction in tetraplegia.

PURPOSE: To evaluate the outcomes of our technique for single-stage grip-release reconstruction and compare it with previous 1- and 2-stage grip reconstructions in tetraplegia. METHODS: A total of 14 patients (16 hands) with tetraplegia underwent a single-stage combination of operations to provide pinch, grip, and release function. We compared the study group with a historical control group of 15 patients (18 hands) who had been treated with staged flexion-extension grip-release reconstructions. Both groups were classified as ocular cutaneous 4. Assessment parameters included grip and pinch strength, maximal opening of the first webspace, and Canadian Occupational Performance Measurement. Both groups were rehabilitated with early active mobilization beginning the first day after surgery. RESULTS: Grip strength and opening of the first webspace were significantly greater in the single-stage group than in the comparative group. Pinch strength was not significantly different between groups. On the Canadian Occupational Performance Measurement score, patients belonging to the single-stage group were highly satisfied (increase of 3.7 points) and could perform several of their self-selected goals (3.5 points of improvement). CONCLUSIONS: The single-stage grip-release reconstruction provides people who have spinal cord injuries and tetraplegia with improved and reliable grip function; active finger flexion, active thumb flexion, passive thumb extension, and passive interossei function can all be achieved through this procedure. Early active mobilization is particularly important in improving functional outcome after this combination of grip reconstruction procedures. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

A single-stage operation for reconstruction of hand flexion, extension, and intrinsic function in tetraplegia: the alphabet procedure.

Surgical reconstruction is an established method to restore grip and grasp function after traumatic cervical spinal cord injury and tetraplegia. It can offer the patient improved ability to perform activities of daily living. Traditionally, surgical reconstruction of hand function has required separate operations for flexors and extensors. Here, we present a combination of procedures that provides key pinch and finger flexion together with opening of hand as a 1-stage operation. This reconstruction includes 7 individual operations that are performed in the following order: (1) split flexor pollicis longus-extensor pollicis longus distal thumb tenodesis, (2) reconstruction of passive interossei, (3) thumb CMC arthrodesis (4) brachioradialis-flexor pollicis longus tendon transfer, (5) extensor carpi radialis longus-flexor digitorum profundus tendon transfer, (6) EPL tenodesis, and (7) extensor carpi ulnaris tenodesis. We have chosen to entitle this reconstruction the alphabet or ABCDEFG procedure, an abbreviation for Advanced Balanced Combined Digital Extensor Flexor Grip reconstruction. To reduce the risk of adhesions after this extensive surgery and to facilitate relearning the activation of transferred muscles with new functions, early active training is performed. It is concluded that this 1-stage combination of operations can reliably provide grip, grasp, and release function in persons with C6 tetraplegia, patient satisfaction is high, time and effort for patient and caregivers are less, and incidence of complications is comparable with other published treatment modalities.

Selective release of the digital extensor hood to reduce intrinsic tightness in tetraplegia.

Patients with tetraplegia may have various degrees of spasticity in the hand ranging from a completely clenched fist to reduced control of grip at triggered spasticity. The objective of the present study was to evaluate the functional effect of the distal ulnar intrinsic release procedure to reduce intrinsic tightness. Seventeen patients with tetraplegia (37 fingers) and with prominent intrinsic tightness were operated on for distal intrinsic release with a modification of the procedure to include only the ulnar side of the proximal phalanx. All the patients had more pronounced tightness on the ulnar than on the radial side of the affected finger. Long fingers were consistently the most affected digits. The intrinsic tightness was released completely in all patients and the range of motion (ROM) was improved by 25%, and up to 45% in mild and severe cases, respectively. The good immediate effects of treatment as shown by increased ROM remained intact by 6 months postoperatively. These data suggest that the distal ulnar intrinsic release procedure is a simple and valuable way of reducing intrinsic tightness and improving hand function and grip for patients with intrinsic tightness. This procedure can be added to other procedures such as lengthening and transfer of tendons.