Nerve Transfer Surgery Research Articles

Anatomic Study and Clinical Application of C7 Nerve Transfer Surgery via the Anterior Vertebral Approach for Central Upper Limb Spastic Paralysis

Objective: To explore the anatomic characteristics of C7 nerve localization, course, and length during cross-transfer surgery of the C7 nerve through the anterior vertebral approach and investigate the feasibility, safety, and clinical efficacy of C7 nerve transfer surgery through the anterior vertebral approach for the treatment of central upper limb spastic paralysis. Methods: Four fresh-frozen adult head and neck samples were selected. C7 nerve transfer surgery was simulated through the anterior vertebral approach. The vertical distance between the C7 nerve and the medial edge of the clavicle, the length of the C7 nerve, and the shortest distance of C7 nerve transfer required through the anterior vertebral approach were measured. This was a retrospective analysis of the clinical data of 2 patients with central upper limb spastic paralysis after C7 nerve transfer surgery at Northern Jiangsu People’s Hospital affiliated with Yangzhou University. The patients were all female, aged 50 to 51 years, with upper limb paralysis on the affected side. The muscle strength was grade 0 or grade 1, and the muscle tension was relatively high. Both patients underwent C7 nerve transfer surgery through the anterior vertebral approach. Upper limb sensation and motor function were observed. Results: Bilateral C7 nerves can be fully exposed and located through the anterior vertebral approach. The C7 nerve runs between the anterior and middle scalene muscles, with a vertical distance of 1.7 to 2.5 (2.1±0.3) cm from the inner edge of the clavicle. The length of the C7 nerve is 5.6 to 6.8 (6.4±0.5) cm, and the shortest distance of C7 nerve transfer through the anterior vertebral approach is 4.8 to 5.7 (5.3±0.4 cm). Two patients with central upper limb paralysis successfully underwent C7 nerve transfer surgery using the anterior vertebral approach. Two patients had normal motor function in the healthy upper limb after surgery but experienced pain and numbness in the healthy upper limb. Both patients recovered within 1 month. Two patients experienced significant relief of spasticity symptoms in the affected upper limb. One patient was followed up for 15 months, and, at the last follow-up, sensation in the affected upper limb was normal, with proximal muscle strength at level 3 and distal muscle strength at level 2. Another patient was followed up for 11 months, and at the last follow-up, sensation in the affected upper limb was normal, with proximal muscle strength at level 1+ and distal muscle strength at level 1. Conclusion: For central upper limb spastic paralysis, C7 nerve transfer surgery through the anterior vertebral approach is safe and feasible and is a good treatment option. Related anatomic research can effectively guide clinical surgery and assist in locating the C7 nerve, and incising the musculus longus colli can shorten the distance of C7 nerve transfer.

A Multicenter Validation of a Novel Prediction Model for Elbow Flexion Recovery after Nerve Transfer Surgery in Brachial Plexus Injuries.

Nerve transfer surgery for brachial plexus injuries exhibits variable success rates, potentially resulting in prolonged limb dysfunction for more than 2 years. A proposed prediction model has been developed to predict the unsuccessful recovery of elbow flexion after the surgery. The model consisted of six variables, namely body mass index 23 kg/m2 or more, smoking, total arm type, donor nerve, ipsilateral upper extremity fracture, and ipsilateral vascular injury. This study aimed to assess the external validity of the model for wider applicability. This retrospective analysis examined the medical records of 213 eligible patients with traumatic brachial plexus injuries who underwent surgery at two referral centers between July 2008 and June 2022. The prediction model was applied to estimate recovery failure probability, which was compared with the observed outcomes for each patient. Both the original and simplified models were validated for discrimination and calibration using metrics including c-statistic, Hosmer-Lemeshow goodness-of-fit test, calibration plot, calibration slope, and intercept. Thirty-two percent of patients experienced unsuccessful elbow flexion recovery. Both the original and simplified models demonstrated good discrimination (c-statistics: 0.748 and 0.759, respectively). The Hosmer-Lemeshow test revealed strong agreement between predicted and observed probabilities for both models (P = 0.66 and P = 0.92, respectively). The calibration plot exhibited good agreement, with a calibration slope of 0.928 and an intercept of 0.377. The prediction model showed strong external validation, confirming its clinical value. High-risk patients should be educated on the risks and benefits of nerve transfer surgery and consider alternative treatments such as primary free functioning muscle transfer.

Optimal Technique for Cutting Peripheral Nerves in Nerve Transfer Surgery: A Survey of Peripheral Nerve Surgeons.

Nerve transfer procedures are performed in patients with proximal nerve injuries to optimize their potential for functional recovery. The study aimed to determine the preferred surgical technique and tool used by peripheral nerve surgeons to transect nerves in nerve transfers. All current members of the American Society of Peripheral Nerve were invited to complete a cross-sectional 10-question survey. Data on practice demographics, nerve-cutting instruments/techniques used, and their belief on whether this impacted patient outcomes were collected. A total of 49 American Society of Peripheral Nerve members participated in the study, the majority of whom were over 10 years into practice (n = 30/49; 61%). The most common response was a scalpel blade (n = 26/49; 53%), with the remaining 47% using iris scissors, micro-serrated scissors, a razor blade, specialized nerve microscissors, or a specialized nerve-cutting device. The number of years in practice (P = 0.0271) and the percentage of practice that involves treating patients with peripheral nerve injuries (P = 0.0054) is significantly associated with the belief that crushing the donor nerves during transection may result in worse outcomes following nerve transfer. Only the latter is significantly associated with this belief in recipient nerves (P = 0.0214). Our findings demonstrate that peripheral nerve surgeons believe that the technique used to transect nerves before coaptation influences outcomes after nerve transfer. Further ex vivo studies are necessary to investigate how different cutting techniques influence nerve morphology and scarring at the coaptation site to optimize outcomes after peripheral nerve surgery.

Acute and post-acute soft tissue reconstruction

The precise analysis of the injured structures requiring reconstruction in complex wound defects is aprerequisite for successful restoration. The fundamental reconstructive strategies for soft tissue defects of the extremities including injuries to vessels, nerves and burn wounds in the context of the acute and post-acute trauma phases are presented. The different phases of soft tissue reconstruction are described. Recommendations for action with respect to the reconstruction of the functional structures are described. Two clinical case examples illustrate the approach. The acute reconstruction phase is defined as the period 0-72 h after the traumatic event and includes surgical debridement, primary reconstruction of nerves and vessels using interpositional grafts if necessary and temporary soft tissue reconstruction. Combined thermomechanical trauma requires early debridement combined with internal fixation of open fractures. In the post-acute reconstruction phase, which is generally defined as aperiod of up to 6weeks after the traumatic event, definitive soft tissue reconstruction is performed. In the case of long reinnervation distances, nerve transfer or motor replacement plastic surgery is performed in the post-acute phase. The reconstruction of soft tissue after trauma necessitates a stage-dependent approach. In the acute phase procedures aim at the immediate preservation of the limb. In the post-acute phase, definitive soft tissue reconstruction is performed to enable maximum functional preservation. Combined thermomechanical injuries require early surgical treatment in order to prevent infections.

Change of function and brain activity in patients of right spastic arm paralysis combined with aphasia after contralateral cervical seventh nerve transfer surgery.

Left hemisphere injury can cause right spastic arm paralysis and aphasia, and recovery of both motor and language functions shares similar compensatory mechanisms and processes. Contralateral cervical seventh cross transfer (CC7) surgery can provide motor recovery for spastic arm paralysis by triggering interhemispheric plasticity, and self-reports from patients indicate spontaneous improvement in language function but still need to be verified. To explore the improvements in motor and language function after CC7 surgery, we performed this prospective observational cohort study. The Upper Extremity part of Fugl-Meyer scale (UEFM) and Modified Ashworth Scale were used to evaluate motor function, and Aphasia Quotient calculated by Mandarin version of the Western Aphasia Battery (WAB-AQ, larger score indicates better language function) was assessed for language function. In 20 patients included, the average scores of UEFM increased by .40 and 3.70 points from baseline to 1-week and 6-month post-surgery, respectively. The spasticity of the elbow and fingers decreased significantly at 1-week post-surgery, although partially recurred at 6-month follow-up. The average scores of WAB-AQ were increased by 9.14 and 10.69 points at 1-week and 6-month post-surgery (P < .001 for both), respectively. Post-surgical fMRI scans revealed increased activity in the bilateral hemispheres related to language centrals, including the right precentral cortex and right gyrus rectus. These findings suggest that CC7 surgery not only enhances motor function but may also improve the aphasia quotient in patients with right arm paralysis and aphasia due to left hemisphere injuries.

Fluoroscopic sniff test as a diagnostic tool for phrenic nerve injury in patients with traumatic brachial plexus injury

OBJECTIVE Traumatic brachial plexus injury (BPI) is a high-morbidity condition with an escalating incidence. One of the treatment options is neurotization using the ipsilateral phrenic nerve. Therefore, diagnosis of nerve dysfunction is a crucial step in preoperative planning. This study aimed to assess the accuracy and reliability of the fluoroscopic sniff test for preoperative diagnosis of phrenic nerve injury in patients with traumatic BPI. METHODS The study was conducted from June 2019 to August 2023 at a tertiary care hospital. A preoperative fluoroscopic sniff test was performed. During brachial plexus surgery, direct phrenic nerve stimulation was conducted as a gold standard of phrenic nerve function. Two nonoperating orthopedic surgeons interpreted the accuracy and reliability of the test. RESULTS Seventy-four patients with traumatic BPI (66 males and 8 females) with a median age of 26 years were enrolled. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the fluoroscopic sniff test were 90.9% (95% CI 75.7%−98.1%), 100% (95% CI 91.4%−100%), 100% (95% CI 88.4%−100%), 93.2% (95% CI 82.3%−97.6%), and 95.9% (95% CI 88.6%−99.2%), respectively. Interobserver reliability showed excellent agreement (κ = 1, p &lt; 0.001). CONCLUSIONS The fluoroscopic sniff test was proven to be an accurate, reliable, and simple tool to evaluate phrenic nerve function in patients with traumatic BPI. Preoperative testing should be performed to reduce operative time to identify the phrenic nerve as a donor for nerve transfer surgery in cases in which no function is detected from the fluoroscopic sniff test.

Virtual Postoperative Rehabilitation after Facial Reanimation Surgery

To develop a standardized post-operative virtual rehabilitation program available to Atlantic Canadians following dual nerve transfer surgery/facial reanimation surgery. To report patient satisfaction outcomes associated with virtual rehabilitation following dual nerve transfer surgery.

Impact of Upper Limb Motor Recovery on Functional Independence After Traumatic Low Cervical Spinal Cord Injury.

Cervical spinal cord injury (SCI) causes devastating loss of upper limb function and independence. Restoration of upper limb function can have a profound impact on independence and quality of life. In low-cervical SCI (level C5-C8), upper limb function can be restored via reinnervation strategies such as nerve transfer surgery. The translation of recovered upper limb motor function into functional independence in activities of daily living (ADLs), however, remains unknown in low cervical SCI (i.e., tetraplegia). The objective of this study was to evaluate the association of patterns in upper limb motor recovery with functional independence in ADLs. This will then inform prioritization of reinnervation strategies focused to maximize function in patients with tetraplegia. This retrospective study performed a secondary analysis of patients with low cervical (C5-C8) enrolled in the SCI Model Systems (SCIMS) database. Baseline neurological examinations and their association with functional independence in major ADLs-i.e., eating, bladder management, and transfers (bed/wheelchair/chair)-were evaluated. Motor functional recovery was defined as achieving motor strength, in modified research council (MRC) grade, of ≥ 3 /5 at one year from ≤ 2/5 at baseline. The association of motor function recovery with functional independence at one-year follow-up was compared in patients with recovered elbow flexion (C5), wrist extension (C6), elbow extension (C7), and finger flexion (C8). A multi-variable logistic regression analysis, adjusting for known factors influencing recovery after SCI, was performed to evaluate the impact of motor function at one year on a composite outcome of functional independence in major ADLs. Composite outcome was defined as functional independence measure score of 6 or higher (complete independence) in at least two domains among eating, bladder management, and transfers. Between 1992 and 2016, 1090 patients with low cervical SCI and complete neurological/functional measures were included. At baseline, 67% of patients had complete SCI and 33% had incomplete SCI. The majority of patients were dependent in eating, bladder management, and transfers. At one-year follow-up, the largest proportion of patients who recovered motor function in finger flexion (C8) and elbow extension (C7) gained independence in eating, bladder management, and transfers. In multi-variable analysis, patients who had recovered finger flexion (C8) or elbow extension (C7) had higher odds of gaining independence in a composite of major ADLs (odds ratio [OR] = 3.13 and OR = 2.87, respectively, p < 0.001). Age 60 years (OR = 0.44, p = 0.01), and complete SCI (OR = 0.43, p = 0.002) were associated with reduced odds of gaining independence in ADLs. After cervical SCI, finger flexion (C8) and elbow extension (C7) recovery translate into greater independence in eating, bladder management, and transfers. These results can be used to design individualized reinnervation plans to reanimate upper limb function and maximize independence in patients with low cervical SCI.

Peripheral nerve transfers for dysfunctions in central nervous system injuries: a systematic review

Background: The review highlights recent advancements and innovative uses of nerve transfer surgery in treating dysfunctions caused by central nervous system (CNS) injuries, with a particular focus on spinal cord injury (SCI), stroke, traumatic brain injury and cerebral palsy. Methods: A comprehensive literature search was conducted regarding nerve transfer for restoring sensorimotor functions and bladder control following injuries of spinal cord and brain, across PubMed and Web of Science from January 1920 to May 2023. Two independent reviewers undertook article selection, data extraction and risk of bias assessment with several appraisal tools, including the Cochrane Risk of Bias Tool, the JBI Critical Appraisal Checklist and SYRCLE’s ROB tool. The study protocol has been registered and reported following PRISMA and AMSTAR guidelines. Results: 906 articles were retrieved, of which 35 studies were included (20 on SCI and 15 on brain injury), with 371 participants included in the surgery group and 192 in the control group. These articles were mostly low-risk, with methodological concerns in study types, highlighting the complexity and diversity. For SCI, the strength of target muscle increased by 3.13 of Medical Research Council grade, and the residual urine volume reduced by more than 100 ml in 15 of 20 patients. For unilateral brain injury, the Fugl-Myer motor assessment (FMA) improved 15.14-26 score in upper extremity compared to 2.35-26 in the control group. The overall reduction in Modified Ashworth score was 0.76-2 compared to 0-1 in the control group. Range of motion (ROM) increased 18.4-80° in elbow, 20.4-110° in wrist and 18.8-130° in forearm, while ROM changed -4.03°-20° in elbow, -2.08°-10° in wrist, -2.26°-20° in forearm in the control group. The improvement of FMA in lower extremity was 9 score compared to the pre-surgery. Conclusion: Nerve transfer generally improves sensorimotor functions in paralyzed limbs and bladder control following CNS injury. The technique effectively creates a “bypass” for signals and facilitates functional recovery by leveraging neural plasticity. It suggested a future of surgery, neurorehabilitation and robotic-assistants converge to improve outcomes for CNS.

Neuromuscular consequences of spinal cord injury: New mechanistic insights and clinical considerations.

The spinal cord facilitates communication between the brain and the body, containing intrinsic systems that work with lower motor neurons (LMNs) to manage movement. Spinal cord injuries (SCIs) can lead to partial paralysis and dysfunctions in muscles below the injury. While traditionally this paralysis has been attributed to disruptions in the corticospinal tract, a growing body of work demonstrates LMN damage is a factor. Motor units, comprising the LMN and the muscle fibers with which they connect, are essential for voluntary movement. Our understanding of their changes post-SCI is still emerging, but the health of motor units is vital, especially when considering innovative SCI treatments like nerve transfer surgery. This review seeks to collate current literature on how SCI impact motor units and explore neuromuscular clinical implications and treatment avenues. SCI reduced motor unit number estimates, and surviving motor units had impaired signal transmission at the neuromuscular junction, force-generating capacity, and excitability, which have the potential to recover chronically, yet the underlaying mechanisms are unclear. Furthermore, electrodiagnostic evaluations can aid in assessing the health lower and upper motor neurons, identify suitable targets for nerve transfer surgeries, and detect patients with time sensitive injuries. Lastly, many electrodiagnostic abnormalities occur in both chronic and acute SCI, yet factors contributing to these abnormalities are unknown. Future studies are required to determine how motor units adapt following SCI and the clinical implications of these adaptations.

Rehabilitation Following a Triceps Branch to Axillary Motor Nerve Transfer-A Pragmatic Therapy Guide.

Peripheral motor nerve transfer surgery is a technique that may be used to restore motor function to paralyzed muscles. Motor nerve transfer involves harvesting an expendable motor nerve branch, and transfer to the motor branch of the denervated target muscle, using microsurgical coaptation. To date, a standardized rehabilitation protocol does not exist. The 6 stages of rehabilitation after motor nerve transfer surgery were outlined by colleagues in the Birmingham Peripheral Nerve Injury service in 2019. This article aims to provide a practical therapy perspective on the rehabilitation stages of motor nerve transfer surgery outlined in that paper, focusing on the radial to axillary nerve transfer. Timeframes for each stage along with exercise prescription and rationale are provided.

Review of outcomes measures used to evaluate upper extremity surgical treatment of cervical spinal cord injury with recommendations for the future

Cervical spinal cord injury is a life-altering event that profoundly affects an individual’s upper extremity function. Nerve transfer surgeries have been shown to restore more natural movement and fine motor control in this population. At present, there is no consensus on how to evaluate the efficacy of these restorative surgeries. The purpose of this work was to perform a comprehensive review of the existing literature and describe the outcome measures used. We hypothesized that the assessments will be heterogeneous across studies and will incompletely capture the effect of nerve transfers on upper extremity motion in cervical spinal cord injury. A search strategy was designed and a review of multiple databases (Embase.com, Ovid-Medline All, and Scopus) yielded 481 articles; 26 unique studies met inclusion criteria and underwent analysis. Both manual muscle strength testing and video content were presented in the majority of studies. Outcome assessments including myometry, functional outcomes measures (such as the grasp and release test), patient-reported outcomes (including generic, extremity, and disease-specific types), and custom de novo questionnaires were used variably across studies. Future work should focus on standardizing outcomes measures in the field and developing and incorporating kinematic analysis to quantify the intricate, coordinated, and precise movement attained after nerve transfer surgery in the setting of cervical spinal cord injury.

Segmental infralesional pathological spontaneous activity in subacute traumatic spinal cord injury.

There is a dearth of knowledge regarding the status of infralesional lower motor neurons (LMNs) in individuals with traumatic cervical spinal cord injury (SCI), yet there is a growing need to understand how the spinal lesion impacts LMNs caudal to the lesion epicenter, especially in the context of nerve transfer surgery to restore several key upper limb functions. Our objective was to determine the frequency of pathological spontaneous activity (PSA) at, and below, the level of spinal injury, to gain an understanding of LMN health below the spinal lesion. Ninety-one limbs in 57 individuals (53 males, mean age = 44.4 ± 16.9 years, mean duration from injury = 3.4 ± 1.4 months, 32 with motor complete injuries), were analyzed. Analysis was stratified by injury level as (1) C4 and above, (2) C5, and (3) C6-7. Needle electromyography was performed on representative muscles innervated by the C5-6, C6-7, C7-8, and C8-T1 nerve roots. PSA was dichotomized as present or absent. Data were pooled for the most caudal infralesional segment (C8-T1). A high frequency of PSA was seen in all infralesional segments. The pooled frequency of PSA for all injury levels at C8-T1 was 68.7% of the limbs tested. There was also evidence of PSA at the rostral border of the neurological level of injury, with 58.3% of C5-6 muscles in those with C5-level injuries. These data support a high prevalence of infralesional LMN abnormalities following SCI, which has implications to nerve transfer candidacy, timing of the intervention, and donor nerve options.

Comparing surgeries to restore upper extremity function in tetraplegia: Impact on function during the perioperative period

Context/Objective To assess short-term changes in health outcomes in people with cervical-level spinal cord injury (SCI) who underwent upper extremity (UE) reconstruction via either novel nerve transfer (NT) or traditional tendon transfer (TT) surgery with individuals who did not undergo UE surgical reconstruction. Design Prospective, comparative cohort pilot study. Participants 34 participants with cervical SCI met the following inclusion criteria: age 18 or older, greater than 6 months post-injury, and mid-cervical level SCI American Spinal Injury Association Impairment Scale (AIS) A, B or C. Setting Two tertiary academic hospitals and their affiliated veterans’ hospitals. Methods Health outcomes were assessed using two previously validated measures, the Spinal Cord Independence Measure (SCIM) and Short-Form Health Survey (SF-36). Demographic, surgical, and survey data were collected at the initial evaluation and one month postoperatively/post-baseline. Results 34 participants with cervical SCI were recruited across three cohorts: no surgery (n = 16), NT (n = 10), and TT (n = 8). The TT group had a decline in SCIM and SF-36 scores whereas the NT and no surgery groups experienced little change in independence or health status in the immediate perioperative period. Conclusions Surgeons and rehabilitation providers must recognize differences in the perioperative needs of people with cervical SCI who chose to have restorative UE surgery. Future work should focus on further investigation of health outcomes, change in function, and improving preoperative counseling and cross-disciplinary management.

Nerve Transfer After Cervical Spinal Cord Injury: Who Has a “Time Sensitive” Injury Based on Electrodiagnostic Findings?

ObjectiveTo use the ulnar compound muscle action potential (CMAP) to abductor digiti minimi (ADM) to identify the proportion of individuals with cervical spinal cord injury (SCI) who have lower motor neuron (LMN) abnormalities involving the C8-T1 spinal nerve roots, within 3-6 months, and thus may influence the response to nerve transfer surgery. DesignRetrospective analysis of prospectively collected data. Data were analyzed from European Multicenter Study About SCI database. SettingMulti-center, academic hospitals. ParticipantsWe included 79 subjects (age=41.4±17.7, range:16-75; 59 men; N=79), who were classified as cervical level injuries 2 weeks after injury and who had manual muscle strength examinations that would warrant consideration for nerve transfer (C5≥4, C8<3). InterventionsNone. Main Outcome MeasuresThe ulnar nerve CMAP amplitude to ADM was used as a proxy measure for C8-T1 spinal segment health. CMAP amplitude was stratified into very abnormal (<1.0 mV), sub-normal (1.0-5.9 mV), and normal (>6.0 mV). Analysis took place at 3 (n=148 limbs) and 6 months (n=145 limbs). ResultsAt 3- and 6-month post-injury, 33.1% and 28.3% of limbs had very abnormal CMAP amplitudes, respectively, while in 54.1% and 51.7%, CMAPs were sub-normal. Median change in amplitude from 3 to 6 months was 0.0 mV for very abnormal and 1.0 mV for subnormal groups. A 3-month ulnar CMAP <1 mV had a positive predictive value of 0.73 (95% CI 0.69-0.76) and 0.78 (95% CI 0.75-0.80) for C8 and T1 muscle strength of 0 vs 1 or 2. ConclusionA high proportion of individuals have ulnar CMAPs below the lower limit of normal 3- and 6-month post cervical SCI and may also have intercurrent LMN injury. Failure to identify individuals with LMN denervation could result in a lost opportunity to improve hand function through timely nerve transfer surgeries.

Effect of shorter nerve graft and selective motor branch of recipient nerve on nerve transfer surgery for elbow flexion in patients with brachial plexus injury.

The spinal accessory nerve (SAN) is commonly used as a donor nerve for reinnervation of elbow flexors in brachial plexus injury (BPI) reconstruction. However, no study has compared the postoperative outcomes between SAN-to-musculocutaneous nerve (MCN) transfer and SAN-to-nerve to biceps (NTB) transfer. Thus, this study aimed to compare the postoperative time to recovery of elbow flexors between the two groups. A total of 748 patients who underwent surgical treatment for BPI between 1999 and 2017 were retrospectively reviewed. Among them, 233 patients were treated with nerve transfer for elbow flexion. Two techniques were used to harvest the recipient nerve: the standard dissection technique and the proximal dissection technique. The postoperative motor power of elbow flexion was assessed every month for 24 months using the Medical Research Council (MRC) grading system. Survival and Cox regression analyses were used to compare the time to recovery (MRC grade ≥ 3) between the two groups. Of the 233 patients who underwent nerve transfer surgery, there were 162 patients in the MCN group and 71 patients in the NTB group. At 24 months after surgery, the MCN group had a success rate of 74.1%, and the NTB group had a success rate of 81.7% (p = 0.208). When compared with the MCN group, the NTB group had a significantly shorter median time to recovery (19 months vs 21 months, p = 0.013). Only 11.1% of patients in the MCN group regained MRC grade 4 or 5 motor power 24 months after nerve transfer surgery compared with 39.4% patients in the NTB group (p < 0.001). Cox regression analysis showed that the SAN-to-NTB transfer in combination with the proximal dissection technique was the only significant factor affecting time to recovery (HR 2.33, 95% CI 1.46-3.72; p < 0.001). SAN-to-NTB transfer in combination with the proximal dissection technique is the preferred nerve transfer option for restoration of elbow flexion in traumatic pan-plexus palsy.

Axonal mapping of motor and sensory components within the ulnar nerve and its branches.

Intrinsic function is indispensable for dexterous hand movements. Distal ulnar nerve defects can result in intrinsic muscle dysfunction and sensory deficits. Although the ulnar nerve's fascicular anatomy has been extensively studied, quantitative and topographic data on motor axons traveling within this nerve remain elusive. The ulnar nerves of 14 heart-beating organ donors were evaluated. The motor branches to the flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP) muscles and the dorsal branch (DoBUN) as well as 3 segments of the ulnar nerve were harvested in 2-cm increments. Samples were subjected to double immunofluorescence staining using antibodies against choline acetyltransferase and neurofilament. Samples revealed more than 25,000 axons in the ulnar nerve at the forearm level, with a motor axon proportion of only 5%. The superficial and DoBUN showed high axon numbers of more than 21,000 and 9300, respectively. The axonal mapping of more than 1300 motor axons revealed an increasing motor/sensory ratio from the proximal ulnar nerve (1:20) to the deep branch of the ulnar nerve (1:7). The motor branches (FDP and FCU) showed that sensory axons outnumber motor axons by a ratio of 10:1. Knowledge of the detailed axonal architecture of the motor and sensory components of the human ulnar nerve is of the utmost importance for surgeons considering fascicular grafting or nerve transfer surgery. The low number of efferent axons in motor branches of the ulnar nerve and their distinct topographical distribution along the distal course of the nerve is indispensable information for modern nerve surgery.

Nerve Transfer Surgery in Acute Flaccid Myelitis: Prognostic Factors, Long-Term Outcomes, Comparison With Natural History

BackgroundNerve transfer surgery is sometimes offered to patients with acute flaccid myelitis (AFM). The objectives of this study were to evaluate surgical efficacy, assess which clinical and neurophysiological data are valuable for preoperative planning, and report long-term outcomes. MethodsThis is a single-center, retrospective case series of patients with AFM who received nerve transfer surgery. All patients had preoperative electromyography and nerve conduction studies (EMG/NCS). Matched control muscles that did not receive nerve transfer surgery were defined in the same cohort. ResultsTen patients meeting inclusion criteria received a total of 23 nerve transfers (19 upper extremity, four lower extremity). The mean age at symptom onset was 3.8 years, surgery was 0.5 to 1.25 years after diagnosis, and mean follow-up was 2.3 years (range 1.3 to 4.5 years). Among muscles with preoperative strength Medical Research Council (MRC) grade 0, muscles receiving nerve transfers performed significantly better than those that did not (MRC grade 2.17 ± 0.42 vs 0 ± 0, respectively, P = 0.0001). Preoperative EMG/NCS predicted worse outcomes in recipient muscles with more abundant acute denervation potentials (P = 0.0098). Donor nerves found to be partially denervated performed equally well as unaffected nerves. Limited data suggested functional improvement accompanying strength recovery. ConclusionsNerve transfer surgery is an effective strategy to restore strength for patients with AFM with persistent, severe motor deficits. Postoperative outcomes in patients with complete paralysis are better than the natural history of disease. This study demonstrates the utility of preoperative clinical and electrophysiological data in guiding patient selection for nerve transfer surgery.

Poster (Clinical/Best Practice Implementation) ID 1998248

Background It is essential that individuals with spinal cord injury set their goals prior to their peripheral nerve transfer (PNT) surgery. Goal setting is a significant factor in pre-operative planning and is one way in which we can track performance and outcomes for these patients. Objectives To describe goal types identified by patients managed in the PNT-SCI rehab program at Lyndhurst-UHN. Cite and report the COPM outcomes in the domains of Self-care and Productivity. Methods A retrospective case series was conducted (n=14), charts were reviewed for type of goals and patient’s perception of goal attainment using COPM for a case series of three patients with tetraplegia who received PNT-SCI surgery and comprehensive rehabilitation. The changes in COPM are reported from baseline to 12 months post-surgery. Each patient identified three goals pre-surgery; their goals and the COPM were used to measure change over time. Results Ninety two percent of the identified goals were in the area of Self Care, and 8% were in the Productivity areas. Two of the patients who received PNT-SCI rehabilitation had an increase of 1 on the COPM, while one individual regressed by 2 points. That individual did not receive comprehensive rehabilitation. Conclusion It is known that recovery after PNT-SCI surgery can take 24 or more months. We reported COPM change scores at 12 months post surgery. The MCID is two points for COPM, ideally over 24 months we will see MCID of three or higher.

Poster (Knowledge Generation) ID 2002621

Background Nerve transfer surgery for patients with spinal cord injury (SCI) is an emergent practice for upper extremity reconstruction currently being implemented in a few clinical settings around the world. In 2019, we implemented an interdisciplinary clinic for upper extremity care in tetraplegic patients. Since the beginning of this collaboration, thirteen patients underwent nerve transfer surgery and followed a specific two-year rehabilitation protocol. Presentation objectives: Methods Thirteen patients underwent a surgical reconstruction of their upper extremity. They followed a rehabilitation process with occupational therapists and physiotherapists. So far, eight patients have completed their two-year rehabilitation process. Routine outcome assessments were collected at 0, 6, 12, 24 months following the surgery. Results Twenty-four arms were operated, for a total of 51 nerve transfers. We will present our epidemiological data, details of the surgeries and results on hand opening, grip and pinch strength, functional testing, as well as satisfaction questionnaires. Conclusion Nerve transfer surgery is an exciting and innovative technique for our SCI patients. An interdisciplinary setting is the key to success. Our data shows that this surgery, well planned and accompanied by proper rehabilitation, is a promising avenue to improve upper extremity function in people with cervical spinal cord injury.