Nerve Transfers to Restore Upper Extremity Function in Cervical Spinal Cord Injury: Update and Preliminary Outcomes

Surgical Strategies for Functional Upper Extremity Reconstruction After Spinal Cord Injury

Spinal cord injuries (SCI) can substantially affect independence and quality of life, particularly by limiting upper extremity function. Surgical reconstruction offers the potential to restore motion in the hand, wrist, and elbow for those with deficits following cervical spinal cord injury. Techniques such as tendon transfer, tenodesis, and arthrodesis-often used in combination-are well-established strategies for enhancing upper extremity function. Nerve transfers have more recently been employed and differ from other procedures in that they are often time sensitive and should be performed before permanent muscle atrophy occurs. A comprehensive preoperative evaluation, including clinical examination and electrodiagnostic assessment, is essential to determine the availability and strength of donor tendons and nerves. The International Classification of Surgery for the Hand in Tetraplegia (ICSHT) system is the most utilized surgical classification for determining muscle that can be used for reconstruction. Based on this classification, prioritization is given to restoring elbow extension, wrist extension, pinch, and grasp. Postoperative rehabilitative therapy balances the need for immobilization while preventing joint stiffness and may also incorporate cortical retraining strategies to activate tendon and nerve transfers. Ultimately, a collaborative, interdisciplinary approach is essential for assessing the injury, determining operative candidacy, selecting the optimal treatment strategy, and providing tailored rehabilitation. This article explores the classification of SCI as it pertains to the upper limb, provides an overview of surgical options, describes the preoperative clinical and electrodiagnostic evaluation process, and discusses reconstructive strategies aimed at improving functional outcomes in individuals with SCI.

Brachialis to Anterior Interosseous Nerve Transfer: Comprehensive Anatomic Rationale

BACKGROUND AND OBJECTIVES

Distal nerve transfers for muscle reinnervation and restoration of function after upper and lower motor neuron lesions are a well-established surgical approach. The brachialis to anterior interosseous nerve (BrAIN) transfer is performed for prehension reanimation in lower brachial plexus and traumatic cervical spinal cord injuries. The aim of the study is to shed light on the inconsistent results observed in patients who undergo the BrAIN transfer.

METHODS

An anatomic dissection was conducted on 30 fresh upper limb specimens to examine the intraneural topography of the median nerve (MN) in the upper arm at the level of the BrAIN transfer and the presence of intraneural fascicular interconnections distally.

RESULTS

Fascicular interconnections between the AIN and other MN branches were consistently found in the distal third of the upper arm. The first interconnection was at 3.85 ± 1.82 cm proximal to the interepicondylar line, and the second one, after further proximal neurolysis, was at 9.45 ± 1.16 cm from the interepicondylar line. Intraneural topography of the AIN at the transfer level varied, with dorsomedial, dorsolateral, and purely dorsal locations observed.

CONCLUSION

Consistent fascicular interconnections between the AIN and MN branches and intraneural topography variability of the MN may lead to aberrant reinnervation.

Effect of Tourniquet-Related Nerve Ischemia on Response to Handheld Nerve Stimulation in Ulnar Nerve Transposition

BACKGROUND

Tourniquet-related nerve ischemia has been well studied in several reconstructive procedures, but the time course of impaired response to intraoperative stimulation is unclear. The present study evaluated ischemic effects on conduction during ulnar nerve transposition and examined the relationship between intraoperative and preoperative diagnostics. The authors hypothesized that intraoperative ischemia would have minimal impact on conduction.

METHODS

Thirty patients scheduled for anterior transposition were enrolled after preoperative examination, electrodiagnostic testing, and ultrasound. Demographic and symptom severity data were recorded. A handheld biphasic nerve stimulator was used intraoperatively to assess minimum amplitude and pulse duration needed for muscle response. Measurements were taken at 15-minute intervals after placement.

RESULTS

Changes in threshold amplitude and pulse duration were calculated between each 15-minute interval; no significant difference was found in the change of either value ( P = 0.70 and P = 0.178). A weak negative correlation existed between preoperative compound muscle action potential amplitudes and average intraoperative pulse duration, which increased to a moderate correlation when compared with 45-minute pulse duration ( r = -0.62; P < 0.01). Preoperative ulnar nerve cross-sectional area demonstrated no significant correlation with average pulse duration but a moderate correlation with pulse duration at 45 minutes ( r = 0.63; P = 0.01).

CONCLUSIONS

Tourniquet use did not prevent effective intraoperative stimulation of the ulnar nerve for at least 45 minutes. The window for meaningful stimulation with tourniquet use appears to be greater than previously thought. Preoperative nerve compound muscle action potential amplitude and cross-sectional area does appear to influence pulse duration required after 45 minutes of ischemia, suggesting that injured nerves are more susceptible to ischemia.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Nerve transfers to anterior interosseous nerve for restoration of finger flexion in spinal cord and brachial plexus injury: a systematic Review and individual-patient-data meta-analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

Cervical spinal cord injury (SCI) and brachial plexus injury (BPI) can result in hand paralysis. Reconstruction of hand motion is associated with improved functionality and quality of life. We synthesized the outcomes of finger and thumb flexion after various nerve transfers to the anterior interosseous nerve (AIN).

METHODS

A systematic literature review and meta-analysis was performed according to the PRISMA guidelines. Successful finger and thumb flexion recovery was defined as Medical research council (MRC) grade ≥3.

RESULTS

In total, 23 studies with 99 patients and 120 nerve transfers to the AIN were performed. The mean interval from injury to surgery was 12.8 months and mean follow-up duration was 24 months. Overall, 81/120 (67.5%) and 68/102 (66.7%) hands achieved successful finger and thumb flexion recovery, respectively. Individual-patient-data were available for 94 nerve transfers. Type of injury (SCI vs BPI/peripheral) did not affect finger flexion outcomes (OR 1.92, 95%CI 0.74-5.0, p = 0.17). On multivariate analysis adjusted for mechanism of injury, timing of injury to surgery and duration of follow-up, utilization of the brachioradialis (BR) branch (25%, 1/4, OR 0.01, 95%CI 0.0006-0.44, p = 0.01) and brachialis (BA) branch (59%, 30/51, OR 0.06, 95%CI 0.006-0.68, p = 0.02) as donors, were associated with statistically significant lower odds of successful finger flexion recovery compared to extensor carpi radialis brevis (ECRB) use (95%, 19/20).

CONCLUSIONS

Similar outcomes were observed with SCI and BPI/peripheral type injuries. ECRB utilization as a donor was superior to BA or BR branch in terms of successful finger flexion recovery.

Restorative Treatments for Cervical Spinal Cord Injury, a Narrative Review

STUDY DESIGN

A narrative review.

OBJECTIVE

To summarize relevant data from representative studies investigating upper limb restorative therapies for cervical spinal cord injury.

SUMMARY OF BACKGROUND DATA

Cervical spinal cord injury (SCI) is a debilitating condition resulting in tetraplegia, lifelong disability, and reduced quality of life. Given the dependence of all activities on hand function, patients with tetraplegia rank regaining hand function as one of their highest priorities. Recovery from cervical SCI is heterogeneous and often incomplete; currently, various novel therapies are under investigation to improve neurological function and eventually better quality of life in patients with tetraplegia.

METHODS

In this article, a narrative literature review was performed to identify treatment options targeting the restoration of function in patients with cervical SCI. Studies were included from available literature based on the availability of clinical data and whether they are applicable to restoration of arm and hand function in patients with cervical SCI.

RESULTS

We describe relevant studies including indications and outcomes with a focus on arm and hand function. Different treatment modalities described include nerve transfers, tendon transfers, spinal cord stimulation, functional electrical stimulation, non-invasive brain stimulation, brain-machine interfaces and neuroprosthetics, stem cell therapy, and immunotherapy. As the authors' institution leads one of the largest clinical trials on nerve transfers for cervical SCI, we also describe how patients undergoing nerve transfers are managed and followed at our center.

CONCLUSIONS

While complete recovery from cervical spinal cord injury may not be possible, novel therapies aimed at the restoration of upper limb motor function have made significant progress toward the realization of complete recovery.

Contemporary Approaches to Peripheral Nerve Surgery

"State of the Art" Learning Objectives: This manuscript serves to provide the reader with a general overview of the contemporary approaches to peripheral nerve reconstruction as the field has undergone considerable advancement over the last 3 decades. The learning objectives are as follows: To provide the reader with a brief history of peripheral nerve surgery and some of the landmark developments that allow for current peripheral nerve care practices.To outline the considerations and management options for the care of patients with brachial plexopathy, spinal cord injury, and lower extremity peripheral nerve injury.Highlight contemporary surgical techniques to address terminal neuroma and phantom limb pain.Review progressive and future procedures in peripheral nerve care, such as supercharge end-to-side nerve transfers.Discuss rehabilitation techniques for peripheral nerve care.

Upper Extremity Nerve Transfers for Treatment of Nerve Injury After Cervical Spine Surgery: A Single-Center Retrospective Review

PURPOSE

Nerve transfers to restore or augment function after spinal cord injury is an expanding field. There is a paucity of information, however, on the use of nerve transfers for patients having undergone spine surgery. The incidence of neurologic deficit after spine surgery is rare but extremely debilitating. The purpose of this study was to describe the functional benefit after upper extremity nerve transfers in the setting of nerve injury after cervical spine surgery.

METHODS

A single-center retrospective review of all patients who underwent nerve transfers after cervical spine surgery was completed. Patient demographics, injury features, spine surgery procedure, nerve conduction and electromyography study results, time to referral to nerve surgeon, time to surgery, surgical technique and number of nerve transfers performed, complications, postoperative muscle testing, and subjective outcomes were reviewed.

RESULTS

Fourteen nerve transfers were performed in 6 patients after cervical spine surgery. Nerve transfer procedures consisted of a transfer between a median nerve branch of flexor digitorum superficialis into a biceps nerve branch, an ulnar nerve branch of flexor carpi ulnaris into a brachialis nerve branch, a radial nerve branch of triceps muscle into the axillary nerve, and the anterior interosseous nerve into the ulnar motor nerve. Average patient age was 55 years; all patients were male and underwent surgery on their left upper extremity. Average referral time was 7 months, average time to nerve transfer was 9 months, and average follow-up was 21 months. Average preoperative muscle grading was 0.9 of 5, and average postoperative muscle grading was 4.1 of 5 ( P < 0.00001).

CONCLUSIONS

Upper extremity peripheral nerve transfers can significantly help patients regain muscle function from deficits secondary to cervical spine procedures. The morbidity of the nerve transfers is minimal with measurable improvements in muscle function.

Current perspectives on peripheral nerve repair and management of the nerve gap

From the first surgical repair of a nerve in the 6th century, progress in the field of peripheral nerve surgery has marched on; at first slowly but today at great pace. Whether performing primary neurorrhaphy or managing multiple large nerve defects, the modern nerve surgeon has an extensive range of tools, techniques and choices available to them. Continuous innovation in surgical equipment and technique has enabled the maturation of autografting as a gold standard for reconstruction and welcomed the era of nerve transfer techniques all while bioengineers have continued to add to our armamentarium with implantable devices, such as conduits and acellular allografts. We provide the reader a concise and up-to-date summary of the techniques available to them, and the evidence base for their use when managing nerve transection including current use and applicability of nerve transfer procedures.

Segmental infralesional pathological spontaneous activity in subacute traumatic spinal cord injury

INTRODUCTION/AIMS

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.

METHODS

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).

RESULTS

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.

DISCUSSION

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.

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

OBJECTIVE

To 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.

DESIGN

Retrospective analysis of prospectively collected data. Data were analyzed from European Multicenter Study About SCI database.

SETTING

Multi-center, academic hospitals.

PARTICIPANTS

We 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).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The 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).

RESULTS

At 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.

CONCLUSION

A 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.

Surgical Reconstruction of Elbow Extension in Spinal Cord Injury and Tetraplegia: A Systematic Review

Purpose

Surgical reconstruction of elbow extension can help restore function in patients with tetraplegia and triceps paralysis because of spinal cord injury. Both posterior deltoid-to-triceps tendon transfer and transfer of the branch of the axillary nerve to the triceps motor branch of the radial nerve have been described for triceps reanimation. This systematic review aimed at reviewing current evidence in the two schools of surgery in terms of their outcome and complication profile.

Methods

A systematic review was conducted using MEDLINE (1974-2023) and EMBASE (1946-2023) databases. The keyword terms "elbow extension," "triceps," "deltoid," "nerve transfer," "spinal cord injury," "tetraplegia," "quadriplegia," and "tetraplegic" were used in the initial search, which was supplemented with manual searches of the bibliographies of retrieved articles.

Results

Twenty studies met our inclusion criteria, with 14 studies (229 limbs) on posterior deltoid-to-triceps tendon transfer, 5 studies (23 limbs) on axillary to radial nerve transfer, and 1 study (1 limb) on combined transfer. For the tendon transfer group, the majority of studies reported a median triceps power of grade 3, with a wide range of failure percentage to reach antigravity (0% to 87.5%). Common complications included gradual stretching of the musculotendinous unit, rupture of the tendon transferred, elbow contracture, and infection. For the nerve transfer group, the majority of studies also reported a median triceps power reaching grade 3. There were no reported complications or loss of power in donor action of shoulder abduction or external rotation.

Conclusions

Transfer of the axillary nerve branch to the triceps motor branch of the radial nerve in tetraplegia shows promising results, with comparable triceps muscle power compared to traditional tendon transfer and a low incidence of complication.

Type of Study/Level of Evidence

Systematic Review III.

[Nerve Transfers in Peripheral Nerve Lesions]

BACKGROUND

Lesions of peripheral nerves of the upper extremities often lead to persistent, serious limitations in motor function and sensory perception. Affected patients suffer from both private and professional restrictions associated with long-term physical, psychological and socioeconomic consequences.

INDICATION

An early indication for a nerve transfer shortens the reinnervation distance and improves the growing of motor and sensory axons into the target organ to facilitate early mobility and sensitivity. When planning the timepoint of the surgical procedure, the distance to be covered by reinnervation as well as the morbidities of donor nerves must be considered individually.

RESULTS

Nerve transfers can achieve earlier and safer reinnervation to improve motor and sensory functions after nerve injuries in the upper extremity.

Caregiving for People With Spinal Cord Injury Undergoing Upper Extremity Reconstructive Surgery: A Prospective Exploration of Lived Experiences, Perioperative Care, and Change Across Time

Background

Nerve transfer (NT) and tendon transfer (TT) surgeries can enhance upper extremity (UE) function and independence in individuals with cervical spinal cord injury (SCI). Caregivers are needed to make this surgery possible, yet caregivers experience their own set of challenges.

Objectives

This comparative study explored the perioperative and nonoperative experiences of caregivers of individuals with cervical SCI, focusing on daily life activities, burden, and mental health.

Methods

Caregivers of individuals with cervical SCI were recruited and grouped by treatment plan for the person with SCI: (1) no surgery (NS), (2) TT surgery, and (3) NT surgery. Semistructured interviews were conducted at baseline/preoperative, early follow-up/postoperative, and late follow-up/postoperative. Caregivers were asked about their daily life, mental health, and challenges related to caregiving. Interviews were audio recorded, transcribed verbatim, and analyzed using thematic analysis. Quantitative, single-item standardized burden score (0-100) data were collected at each timepoint.

Results

Participants included 23 caregivers (18 family members, 4 friends, 1 hired professional). The surgeries often brought hope and motivation for caregivers. Caregivers reported increased burden immediately following surgery (less for the NT compared to TT subgroup) yet no long-term changes in the amount and type of care they provided. NS caregivers discussed social isolation, relationship dysfunction, and everyday challenges.

Conclusion

Health care providers should consider the changing needs of SCI caregivers during perioperative rehabilitation. As part of the shared surgical decision-making approach, providers should educate caregivers about the postoperative process and the extent and potential variability of short- and long-term care needs.

Spinal Cord Injury: Epidemiology, Spontaneous Recovery, and Hand Therapy for the Reconstructive Hand Surgeon

People with spinal cord injury (SCI) prioritize hand function above all else as a reconstructive goal, yet remain a markedly undertreated population by hand surgeons. This review article provides an overview of the epidemiology of SCI and the unmet clinical need of these patients. Further, this article outlines the natural history of SCI, including the expected spontaneous recovery over time and the expectations of hand function when treated with hand therapy alone. This review aims to equip reconstructive hand surgeons with a sound understanding of the basic principles of SCI and recovery and provide a rationale for when to intervene with surgery. In the last decade, this field has changed dramatically with the advent of reliable nerve transfers, making referral and surgical intervention time-sensitive. Therefore this review aims to highlight the expectations from hand therapy alone in this group, the urgent need for early referral to allow nerve transfer options to be viable, and the strategies for overcoming the barriers to these referrals. This offers the opportunity for surgeons to expand their tetraplegia practices while maximizing the considerable contributions to the hand function and quality of life of these patients.

Elevated Body Mass Index Negatively Impacts Recovery of Shoulder Abduction Strength in Triceps Motor Branch to Axillary Nerve Transfers

BACKGROUND

The purpose of this work was to evaluate the clinical outcomes of triceps motor branch to axillary nerve transfers and to identify prognostic factors which may influence these outcomes.

METHODS

A retrospective cohort included all patients who underwent a triceps motor branch to axillary nerve transfer (2010-2019) with at least 12 months of follow-up. The primary outcome measure was shoulder abduction strength assessed with British Medical Research Council (MRC) grade.

RESULTS

Ten patients were included with a mean follow-up of 19.1 (SD 5.9) months. Compared with preoperative MRC shoulder abduction strength (0.2 SD 0.4), patients significantly improved postoperatively (2.8 SD 1.6; P = .005). Increased body mass index (BMI) was significantly associated with worse postoperative MRC (P = .014).

CONCLUSION

Triceps motor branch to axillary nerve transfer is a beneficial procedure for restoring shoulder function in patients presenting with either isolated axillary nerve or brachial plexus pathology. Patients with elevated BMI may not have as robust strength recovery and should be counseled carefully regarding prognosis.

Quantifying Donor Deficits Following Nerve Transfer Surgery in Tetraplegia

PURPOSE

Nerve transfer (NT) surgery can improve function in people with cervical spinal cord injury (SCI). However, the impact of donor nerve deficits remains unclear. The purpose of this study was to quantify donor deficits experienced by individuals with cervical SCI following NT.

METHODS

This prospective single-arm, comparative study included people with SCI undergoing upper extremity NTs. Myometry was used to assess muscle strength at baseline and follow-up. The Spinal Cord Independence Measure was used to measure the ability to perform activities of daily living.

RESULTS

Ten individuals underwent 20 NTs to restore elbow extension (donor, posterior deltoid; n = 2), hand opening (donor, supinator; n = 7), and hand closing (donor, brachialis; n = 11). Shoulder abduction strength decreased (-5.6% at early and -4.5% late follow-up) in the elbow extension NT. Wrist extension strength decreased at early (-46.9% ± 30.3) and increased by late (76.4% ± 154.0) follow-up in the hand opening NT. No statistically significant change in elbow flexion strength was noted in the hand closing NT. Spinal Cord Independence Measure scores did not change significantly between baseline and early postoperative follow-up; they improved at late follow-up.

CONCLUSIONS

Use of expendable donor nerves with redundant function to perform NT surgery has relatively little impact on strength or capacity to perform activities of daily living, even in the unique and highly vulnerable SCI population. Early, temporary loss in wrist extension strength can be seen after the supinator to posterior interosseous nerve transfer. This study offers quantitative data about possible diminution of donor function after NT, enabling hand surgeons to better counsel individuals contemplating upper extremity reconstruction.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.

The Anatomy of Nerve Transfers Used in Tetraplegic Hand Reconstruction

PURPOSE

To evaluate the anatomy of nerve transfers used to reconstruct wrist extension, hand opening, and hand closing in tetraplegic patients.

METHODS

Nerve transfers were completed on 18 paired cadaveric upper limbs. The overlap of donor and recipient nerves was measured, as well as the distance to the target muscle. Axons were counted in each nerve and branch, with the axon percentage calculated by dividing the donor nerve count by that of the recipient.

RESULTS

Transfers with overlap of the donor and recipient nerve were from the radial nerve branch to extensor carpi radialis brevis to anterior interosseous nerve (AIN) and from the branch(es) to supinator to posterior interosseous nerve. The extensor carpi radialis brevis to AIN had the shortest distance to the target, with the branch to brachialis to AIN being the longest. The nerve transfers for wrist extension had the highest axon percentage. Of the transfers for hand closing, the brachialis to AIN had the highest axon percentage, and the branch to brachioradialis to AIN had the lowest.

CONCLUSIONS

The anatomical features of nerve transfers used in tetraplegic hand reconstruction are variable. Differences may help explain clinical outcomes.

CLINICAL RELEVANCE

This study demonstrates which nerve transfers may be anatomically favorable for restoring hand function in tetraplegic patients.

Pre-operative electrodiagnostic planning for upper limb peripheral nerve transfers in cervical spinal cord injury: A Narrative Review

Peripheral nerve transfer (PNT) to improve upper limb function following cervical spinal cord injury (SCI) involves the transfer of supralesional donor nerves under voluntary control to intralesional or sublesional lower motor neurons not under voluntary control. Appropriate selection of donor and recipient nerves and surgical timing impact functional outcomes. While the gold standard of nerve selection is intra-operative nerve stimulation, preoperative electrodiagnostic (EDX) evaluation may help guide surgical planning. Currently there is no standardized preoperative EDX protocol. This study reviews the EDX workup preceding peripheral nerve transfer surgery in cervical SCI, and proposes an informed EDX protocol to assist with surgical planning. The PICO (Population, Intervention, Comparison, Outcome) framework was used to formulate relevant MeSH terms and identify published cases of PNT in cervical SCI in Medline, Embase, CINAHL, and Emcare databases in the last 10 years. The electrodiagnostic techniques evaluating putative donor nerves, recipient nerve branches, time-sensitivity of nerve transfer and other electrophysiological parameters were summarized to guide creation of a preoperative EDX protocol. Needle electromyography (EMG) was the most commonly used EDX technique to identify healthy donor nerves. Although needle EMG has also been used on recipient nerves, compound muscle action potential (CMAP) amplitudes may provide a more accurate determination of recipient nerve health and time-sensitivity for nerve transfer. While there has been progress in pre-surgical EDX evaluation, EMG and NCS approaches are quite variable, and each has limitations in their utility for pre-operative planning. There is need for standardization in the EDX evaluation preceding peripheral nerve transfer surgery to assist with donor and recipient nerve selection, surgical timing and to optimize outcomes. Based on results of this review, herein we propose the PreSCIse (PRotocol for Electrodiagnosis in SCI Surgery of the upper Extremity) pre-operative EDX panel to achieve said goals through an interdisciplinary and patient-centered approach. This article is protected by copyright. All rights reserved.

Donor activation focused rehabilitation approach to hand closing nerve transfer surgery in individuals with cervical level spinal cord injury

STUDY DESIGN

Case Series.

OBJECTIVES

To describe the donor activation focused rehabilitation approach (DAFRA) in the setting of the hand closing nerve transfers in cervical spinal cord injury (SCI) so that therapists may apply it to treatment of individuals undergoing this procedure.

SETTING

United States of America-Academic Level 1 Trauma Center.

METHODS

We reviewed the records of individuals with cervical SCI who underwent nerve transfer to restore hand closing and post-surgery DAFRA therapy at our institution. The three post-surgery phases of DAFRA included (1) early phase (0-12 months) education, limb preparation, and donor activation exercises, (2) middle phase (12-24 months) volitional recipient muscle activation and (3) late phase (18 + months) strengthening and incorporation of motion in activities of daily living.

RESULTS

Subtle gains in hand closing were first observed at a mean of 8.4 months after hand closing nerve transfer surgery. Remarkable improvements including discontinuation of assistive devices, independence with feeding and urinary function, and measurable grip were observed. Function continued to improve slowly for one to two more years.

CONCLUSIONS

A deliberate, slow-paced (monthly for >2 years post-surgery) and incremental therapy program-DAFRA-can be used to improve outcomes after nerve transfer to restore hand closing in cervical SCI.

SPONSORSHIP

This work was made possible by funding from the Craig H. Neilsen Foundation Spinal Cord Injury Research on the Translation Spectrum (SCIRTS) Grant: Nerve Transfers to Restore Hand Function in Cervical Spinal Cord Injury (PI: Ida Fox).

Nerve Transfer of Brachialis Branch to Anterior Interosseus Nerve Using In Situ Lateral Antebrachial Cutaneous Nerve Graft in Tetraplegia

PURPOSE

Reconstruction of finger motion is a therapeutic goal in tetraplegic patients. Although nerve transfer of the brachialis branch of the musculocutaneous nerve to the anterior interosseus nerve has been previously described, this results in unreliable reinnervation because the donor nerve is proximal to the target muscle. We describe an alternative technique in which nerve transfer is performed using the lateral antebrachial cutaneous nerve as a vascular in situ nerve graft. The clinical results are reported.

METHODS

Nine upper limbs of 6 patients (mean age 25 years) with tetraplegia were subjected to brachialis-to-anterior interosseus nerve transfer using the lateral antebrachial cutaneous nerve as a vascular in situ nerve graft, at a mean of 6 months after injury. Additional supinator branch transfer to the posterior interosseous nerve was performed for 6 upper limbs and to the flexor digitorum superficialis motor branch for 1 upper limb.

RESULTS

At a mean of 2 years of follow-up, thumb and finger flexion strength scored M3-M4 in 5 of the 9 limbs according to the Medical Research Council scale. Key pinch and grip pinch averaged 0.6 kg (range, 0-1.0 kg) and 2.2 kg (range, 0-8 kg), respectively. No donor-site deficit was observed.

CONCLUSIONS

Brachialis-to-anterior interosseus nerve transfer with an in situ lateral antebrachial cutaneous nerve graft can be used to reconstruct thumb and finger flexion in tetraplegic patients. Combined with supinator-to- posterior interosseous nerve transfer, simultaneous active extension of the fingers can be achieved.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Patient perspectives and self-rated knowledge of nerve transfer surgery for restoring upper limb function in spinal cord injury

BACKGROUND

Nerve transfer surgery has the potential to restore upper limb function in patients with spinal cord injury (SCI); however, there has been limited exploration of patient perception of nerve transfer.

OBJECTIVE

To explore the perspectives of patients with chronic SCI (>2 years from injury) on nerve transfer surgery, and to determine if an educational intervention improved participants' perceived knowledge levels about the procedure.

DESIGN

Mixed-methods study including qualitative semi-structured interviews and self-reported rating scales. Pre- and post-interviews were completed following an educational presentation.

SETTING

Two local SCI clinics.

PARTICIPANTS

Ten patients with chronic traumatic SCI and neurological level of injury C3-C7 (motor complete or incomplete), recruited via snowball sampling (six male, four female).

INTERVENTION

An educational slide presentation on nerve transfer concepts.

MAIN OUTCOME MEASURES

The primary study outcome measure is the participants' responses to interview questions. The secondary study outcome measure is their self-reported knowledge levels of nerve transfer before and after education.

RESULTS

Regaining upper limb function was a priority for all participants. Although most participants had heard of nerve transfer, none were offered it at the time of their SCI, and only two stated that they had any peers who had undergone the procedure. The educational module significantly increased self-rated scores on understanding of nerve transfer (p < .05). Although all participants were open to nerve transfer after the educational module, they described weighing different factors, including (1) potential for loss versus gain of function, (2) inadequate knowledge about nerve transfer, (3) recovery time, and (4) determining their eligibility for the surgery.

CONCLUSIONS

These findings suggest that people with SCI have limited understanding of nerve transfer as a potential option and would benefit from educational opportunities to help them make informed decisions. This study may inform the development of patient resources to improve pre-surgical consultation and informed decision-making.

Optimizing nerve transfer surgery in tetraplegia: clinical decision making based on innervation patterns in spinal cord injury

OBJECTIVE

Nerve transfers are increasingly being utilized in the treatment of chronic tetraplegia, with increasing literature describing significant improvements in sensorimotor function up to years after injury. However, despite technical advances, clinical outcomes remain heterogenous. Preoperative electrodiagnostic testing is the most direct measure of nerve health and may provide prognostic information that can optimize preoperative patient selection. The objective of this study in patients with spinal cord injury (SCI) was to determine various zones of injury (ZOIs) via electrodiagnostic assessment (EDX) to predict motor outcomes after nerve transfers in tetraplegia.

METHODS

This retrospective review of prospectively collected data included all patients with tetraplegia from cervical SCI who underwent nerve transfer at the authors' institution between 2013 and 2020. Preoperative demographic data, results of EDX, operative details, and postoperative motor outcomes were extracted. EDX was standardized into grades that describe donor and recipient nerves. Five zones of SCI were defined. Motor outcomes were then compared based on various zones of innervation.

RESULTS

Nineteen tetraplegic patients were identified who underwent 52 nerve transfers targeting hand function, and 75% of these nerve transfers were performed more than 1 year postinjury, with a median interval to surgery following SCI of 24 (range 8-142) months. Normal recipient compound muscle action potential and isolated upper motor neuron injury on electromyography (EMG) were associated with greater motor recovery. When nerve transfers were stratified based on donor EMG, greater motor gains were associated with normal than with abnormal donor EMG motor unit recruitment patterns. When nerve transfers were separated based on donor and recipient nerves, normal flexor donors were more crucial than normal extensor donors in powering their respective flexor recipients.

CONCLUSIONS

This study elucidates the relationship of the preoperative innervation zones in SCI patients to final motor outcomes. EDX studies can be used to tailor surgical therapies for nerve transfers in patients with tetraplegia. The authors propose an algorithm for optimizing nerve transfer strategies in tetraplegia, whereby understanding the ZOI and grade of the donor/recipient nerve is critical to predicting motor outcomes.

Upper Extremity Surgery in Tetraplegia and the Online Information Void

Background: People with tetraplegia lack awareness of, and subsequently underutilize, reconstructive surgery to improve upper extremity function. This is a topic of international discussion. To bridge the information gap, proposed mandates encourage providers to discuss surgical options with all tetraplegic patients. Outside of the clinical setting, little is known about information available to patients and caregivers-particularly online. The purpose of this study is to evaluate online content for surgical options for improved upper extremity function for people with tetraplegia. Methods: A sample of online content was generated using common search engines and 2 categories of key words and phrases, general and specific. Articles on the first 2 search pages were evaluated for content and audience. Results: A total of 76 different search results appeared on the first 2 pages using 8 unique search phrases. Of articles generated from general phrases, only 5% mentioned tendon or nerve transfers in tetraplegia. When more specific key search phrases were used, the number of lay articles increased to 71%. Conclusions: Based on initial results, general online information on the management of tetraplegia largely excludes discussions of upper limb reconstruction and the well-known benefits. Unless patients, their caregivers, and nonsurgical health care providers have baseline knowledge of tendon and/or nerve transfers, they are unlikely to obtain de novo awareness of surgical options with self-initiated searches. Thus, the challenge and opportunity is to revise the online dialogue to include upper extremity surgery as a fundamental tenet of tetraplegia care.

Importance of brain alterations in spinal cord injury

Spinal cord injury (SCI) destroys the sensorimotor pathway and blocks the information flow between the peripheral nerve and the brain, resulting in autonomic function loss. Numerous studies have explored the effects of obstructed information flow on brain structure and function and proved the extensive plasticity of the brain after SCI. Great progress has also been achieved in therapeutic strategies for SCI to restore the "re-innervation" of the cerebral cortex to the limbs to some extent. Although no thorough research has been conducted, the changes of brain structure and function caused by "re-domination" have been reported. This article is a review of the recent research progress on local structure, functional changes, and circuit reorganization of the cerebral cortex after SCI. Alterations of structure and electrical activity characteristics of brain neurons, features of brain functional reorganization, and regulation of brain functions by reconfigured information flow were also explored. The integration of brain function is the basis for the human body to exercise complex/fine movements and is intricately and widely regulated by information flow. Hence, its changes after SCI and treatments should be considered.

Evaluation of Functional Independence in Cervical Spinal Cord Injury: Implications for Surgery to Restore Upper Limb Function

PURPOSE

To help individuals make informed choices regarding the optimal type and timing of restorative surgical treatment for cervical spinal cord injury (SCI), more precise information is needed on their ability to perform activities of daily living. The goal of this work was to describe functional independence achieved by individuals with differing levels of cervical SCI.

METHODS

Using the comprehensive European Multicenter Study of Spinal Cord Injury dataset, analysis was undertaken of individuals with traumatic SCI, motor-level C5-C8. Data on feeding, bladder management, and transfers (bed to wheelchair) were compared between individuals with different levels of injury. Subgroup analyses of symmetrical and asymmetrical SCI and between complete and incomplete SCI were performed. The impact of age, sex, and time postinjury on functional independence was ascertained.

RESULTS

Data were available for individuals with symmetrical (n = 204) and asymmetrical (n = 95) patterns of SCI. Independence with feeding, urinary function, and transfer ability was increased in individuals with strong finger flexion. Unexpectedly, the presence of strong elbow extension did not uniformly result in the ability to transfer independently. There was no change in any of the analyzed activities between 6 and 12 months postinjury.

CONCLUSIONS

People with cervical SCI who gain finger flexion have greater independence with feeding, urinary, and transfer activities. Restoration of finger flexion should be a reconstructive priority for individuals with midcervical-level SCI.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Nerve transfers in tetraplegia: a review and practical guide

INTRODUCTION

Spinal cord injury (SCI) may lead to tetraplegia. Several nerve transfers have been successfully used for the restoration of the upper limb in tetraplegia. Reconstruction of an upper limb is individualized based on the functional level. In this study, the authors reviewed nerve transfers based on the injury level for the restoration of upper limb function in tetraplegia.

EVIDENCE ACQUISITION

We performed this study to review nerve transfers in tetraplegia by searching MEDLINE and EMBASE databases to identify relevant articles published through December 2020. We selected studies that reported cases in tetraplegia and extracted information on demographic data, clinical characteristics, operative details, and strength outcomes based on each injury level after surgery.

EVIDENCE SYNTHESIS

Total of 29 journal articles reporting on 275 nerve transfers in 172 upper limbs of 121 patients were included in the review. The mean time between SCI and nerve transfer surgery was 21.37 months (range: 4-156 months), and the follow-up time was 21.34 months (range: 3-38 months). The best outcomes were achieved for the restoration of wrist/finger extension and elbow extension.

CONCLUSIONS

Nerve transfer can provide a new function in tetraplegic patients' upper limbs to improve daily living activities. The type of surgical procedure should be performed based on the functional level of SCI and the individual's needs. Functional recovery occurs more in extensor muscles than flexors. Nerve transfer is a promising option in the reconstruction of upper limb function in tetraplegia.

Research progress on limb spasmolysis, orthopedics and functional reconstruction of brain-derived paralysis

Brain-derived paralysis is a disease dominated by limb paralysis caused by various brain diseases. The damage of upper motor neurons can lead to spastic paralysis of the limbs in different parts. If it cannot be treated in time and effectively, it will severely affect the motor function and ability of daily living. Treating limb spastic dysfunction in patients with brain-derived paralysis is a global problem. Presently, there are many alternative surgical methods. This article mainly reviews the treatment of limb spastic dysfunction with brain-derived paralysis, focusing on three aspects: limb spasmolysis, orthopedics, and functional reconstruction. Among them, the transposition of the peripheral nerve helps limb function with spastic paralysis and can effectively alleviate limb spasticity.

[Selective neurotization of the median nerve in young patients with CV-CVIIcomplicated spinal cord injury]

BACKGROUND

Complicated spinal cord injury occurs in 1-5 cases per 100.000. In children, cervical trauma makes up 72% of all spinal trauma. Spinal cord injury complicates vertebral trauma in 25-50% of cases that usually results severe disability. Rehabilitation of these patients is usually ineffective or results a little improvement. Restoration of even minimal movements is essential in these patients. There are reports devoted to surgical rehabilitation of important hand functions after cervical spinal cord injury.

OBJECTIVE

To demonstrate the restoration of key hand functions in patients with C_V-C_VII complicated spinal cord injury using selective neurotization of the median nerve.

MATERIAL AND METHODS

Three patients aged 17-19 years with complicated C_V-C_VII spinal cord injury and ASIA class A have been selected for surgery for 2 years. Mean period after rehabilitation was 11.3 months. Prior to surgery, all patients recovered flexion/extension in the elbow joints, forearm rotation, flexion and extension of hands. However, there were no active movements in distal phalanges of the fingers, and initial signs of flexor contracture were observed.

RESULTS

Surgical strategy included selective neurotization of the median nerve with a motor branch of musculocutaneous nerve. In one case, we used additional neurotization of posterior interosseous nerve. Two patients recovered cylindrical grip up to M4 and pinch grip up to M3 within 15 months. In the third patient, postoperative data were not assessed due to short-term follow-up.

CONCLUSION

Selective neurotization of anterior interosseous nerve may be considered as a stage or independent surgery for restoration of key hand functions. This approach improves the quality of life in patients with complicated spinal cord injury.

Upper Limb Reconstruction in Tetraplegic Patients: A Primer for Spinal Cord Injury Specialists

Cervical spinal cord injury (SCI) often causes debilitating loss of function of the upper limb. Upper extremity reconstruction surgery can restore some of the upper limb function in tetraplegic patients with SCI. The procedures are typically muscle-tendon unit transfer surgeries, which redistribute the remaining functional muscles to restore active elbow extension, key grip, and finger grasping. In addition to the tendon transfer surgeries, nerve transfers have emerged recently and are showing promising results. However, despite more than half of the tetraplegic patients can benefit from upper limb surgery, only a few of them receive the procedures. This missed opportunity may be due to the lack of communication between SCI specialists and hand surgeons, or the lack of awareness of such options among the specialists and patients. In this review, we provide a basic overview of upper limb reconstruction in tetraplegic patients with target audience of SCI specialists for their better understanding of the basic concept of surgery and information for patient consultation before referring to hand surgeons.

The Utilization of Nerve Transfer for Reestablishing Shoulder Function in the Setting of Acute Flaccid Myelitis: A Single-Institution Review

BACKGROUND

Acute flaccid myelitis (AFM) is a rare disease of young children. The typical presentation involves acute-onset flaccid paralysis in one or more extremities with a nonspecific viral prodrome. Long-term outcomes demonstrate that functional recovery plateaus around six to nine months. The purpose of this study was to evaluate the efficacy of nerve transfers for restoring shoulder function in these patients.

METHODS

A retrospective review of all patients diagnosed with AFM at a single institution. Shoulder function was evaluated using the active movement scale (AMS). Children at a minimum of six months after diagnosis with plateaued shoulder AMS scores of 4 or less were indicated for surgery.

RESULTS

Eleven patients were identified with a mean time from symptom onset to surgery of 12 months. Average follow-up was 19 months. The mean AMS score at follow-up for shoulder external rotation and abduction was 4.6 and 2.8, respectively. A total of six different nerve transfers with five different donor nerves were used individually or in conjunction with each other. The most common transfers were from the spinal accessory nerve to the suprascapular nerve (n = 8) and from the intercostal nerves ×3 to the axillary nerve (n = 5). Patients who received a transfer from the radial nerve to the axillary nerve (n = 2) had the best functional returns, with the mean AMS score of 6.5 in both external rotation and abduction at follow-up.

CONCLUSION

Nerve transfer procedures may help restore shoulder function in the setting of AFM. Combination procedures that involve a transfer from the radial nerve to the axillary nerve may provide the best functional results.

Upper-Extremity Reconstruction in Tetraplegia: A Critical Analysis Review

Management of tetraplegia should be individualized to a patient's particular deficiencies and functional goals. Surgical decision-making for upper-extremity reconstruction in patients with tetraplegia relies on a thorough physical examination to determine which nerves and muscles remain under volitional control with adequate strength for transfer. Peripheral nerve transfers, either in conjunction with or in place of traditional tendon transfers, enable providers to offer an expanded set of surgical options for patients with tetraplegia who are seeking upper-extremity reconstruction. All upper-extremity reconstructive efforts should be carefully considered with regard to their potential effects on the availability of future reconstructive efforts.

Nothing to lose: a phenomenological study of upper limb nerve transfer surgery for individuals with tetraplegia

Purpose: For individuals with tetraplegia, regaining upper limb function forms the highest priority for improving quality of life. Use of nerve transfers to reconstruct upper limb function is increasing, however little is known about individual's decision to have and experience of the surgery and associated rehabilitation outcomes. This qualitative study aimed to understand the experience of surgery on the lives of individuals with tetraplegia 18 months post-surgery.Method: In-depth, semi-structured interviews were conducted with five purposively selected individuals who have undergone upper limb nerve transfers at a metropolitan health service, Melbourne, Australia, specializing in spinal cord injury rehabilitation. Collaizi's phenomenological framework guided data analysis, resulting in an essence statement describing the individuals' experience.Results: An essence statement comprising three themes; Deciding on Surgery, Facing Challenges: Surgery to Recovery and Evaluating Surgical Outcomes, was developed.Conclusion: The study suggests that for individuals with tetraplegia, hope to regain lost upper limb function forms a core consideration in the decision to have surgery. For clinicians supporting patient's decision, balancing hope with the realities of surgery is important. Even small changes in upper limb function had an important influence on participant's confidence in social situations through enhanced participation in a range of everyday activities.IMPLICATIONS FOR REHABILITATIONIn making a decision to have surgery, individuals with tetraplegia benefit from two way discussions with the healthcare team and others who have already undergone surgery.Healthcare teams need to help prepare individuals for the challenges of surgery including: expectations of pain, hospital stay, initial loss of independence and the time it may take to see re-innervation of target muscles and subsequent functional changes.Surgery should be routinely considered as individuals' report that even small changes in upper limb function positively increases participation in everyday tasks and confidence in social situations.When evaluating changes in upper limb function, patient-centered measures should be used.

Combined nerve and tendon transfer to restore elbow extension in tetraplegic patients: surgical technique and case report

INTRODUCTION

In individuals with tetraplegia, elbow extension is critical for overhead activities, weight shifting, independent transfers, and to perform self-care tasks such as eating. At present, restoration of elbow extension in tetraplegic patients can be performed using either tendon or nerve transfers. Each procedure presents several advantages and limitations that must be discussed with the potential surgical candidate, based on remaining muscular functions and functional goals.

CASE PRESENTATION

We propose a novel combined technique of both tendon and nerve transfer to restore active elbow extension by transferring the posterior deltoid tendon to the triceps tendon and the branch of teres minor nerve to the long head of the triceps nerve. Techniques were performed from the same shoulder posterior surgical approach.

DISCUSSION

This surgical technique can add the benefits of each tendon and nerve transfer, leading to a reduction of failure rates, with more predictable outcomes.

Evaluation for Late Nerve Transfer Surgery in Spinal Cord Injury: Predicting the Degree of Lower Motor Neuron Injury

PURPOSE

Nerve transfer surgery is used to restore upper extremity function following cervical spinal cord injury (SCI) with substantial variation in outcomes. The injury pattern in SCI is complex and can include isolated upper motor neuron (UMN) and combined UMN/lower motor neuron (LMN) dysfunction. The purpose of the study was to determine the most effective diagnostic technique for determining suitable candidates for nerve transfer surgery in SCI.

METHODS

Medical records were reviewed of patients who had nerve transfers to restore upper extremity function in SCI. Data collected included (1) preoperative clinical examination and electrodiagnostic testing; (2) intraoperative neuromuscular stimulation (NMS); and (3) nerve histopathology. Preoperative, intraoperative, and postoperative data were compared to identify predictors of isolated UMN versus combined UMN/LMN injury patterns.

RESULTS

The study sample included 22 patients with 50 nerve transfer surgeries and included patients ranging from less than 1 year to over a decade post-SCI. Normal recipient nerve conduction studies (NCS) before surgery corresponded to the intraoperative presence of recipient NMS and postoperative histopathology that showed normal nerve architecture. Conversely, abnormal recipient NCS before surgery corresponded with the absence of recipient NMS during surgery and patterns of denervation on postoperative histopathology. Normal donor preoperative manual muscle testing corresponded with the presence of donor NMS during surgery and normal nerve architecture on postoperative histopathology. An EMG of corresponding musculature did not correspond with intraoperative donor or recipient NMS or histopathological findings.

CONCLUSIONS

NCS better predict patterns of injury in SCI than EMG. This is important information for clinicians evaluating people for late nerve transfer surgery even years post-SCI.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Evidence for efficacy of new developments in reconstructive upper limb surgery for tetraplegia

Nerve transfers are increasingly utilized for upper limb reconstruction in tetraplegia. We reviewed the literature for results achieved by nerve transfers for elbow extension, wrist control and finger and thumb flexion and extension. Muscle strength grading was the only outcome measure consistently reported. The results confirm that nerve transfers can effectively reanimate muscles in selected cases, with comparable strength with those achieved with tendon transfer for elbow extension but inferior strength for finger and thumb flexion. Transfer of supinator nerve branches to the posterior interosseous nerve appears to be reliable and offers increased span and better hand opening than is observed after tendon transfers. Only one publication demonstrated how reinnervation of muscles with nerve transfers translated into improved function, activity and participation for patients. More prospective studies, using standardized outcome measures, are needed to define the precise role of nerve transfers.

Nerve transfers in the upper extremity following cervical spinal cord injury. Part 1: Systematic review of the literature

OBJECTIVE

Patients with cervical spinal cord injury (SCI)/tetraplegia consistently rank restoring arm and hand function as their top functional priority to improve quality of life. Motor nerve transfers traditionally used to treat peripheral nerve injuries are increasingly being used to treat patients with cervical SCIs. In this study, the authors performed a systematic review summarizing the published literature on nerve transfers to restore upper-extremity function in tetraplegia.

METHODS

A systematic literature search was conducted using Ovid MEDLINE 1946-, Embase 1947-, Scopus 1960-, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and clinicaltrials.gov to identify relevant literature published through January 2019. The authors included studies that provided original patient-level data and extracted information on clinical characteristics, operative details, and strength outcomes after nerve transfer procedures. Critical review and synthesis of the articles were performed.

RESULTS

Twenty-two unique studies, reporting on 158 nerve transfers in 118 upper limbs of 92 patients (87 males, 94.6%) were included in the systematic review. The mean duration from SCI to nerve transfer surgery was 18.7 months (range 4 months-13 years) and mean postoperative follow-up duration was 19.5 months (range 1 month-4 years). The main goals of reinnervation were the restoration of thumb and finger flexion, elbow extension, and wrist and finger extension. Significant heterogeneity in transfer strategy and postoperative outcomes were noted among the reports. All but one case report demonstrated recovery of at least Medical Research Council grade 3/5 strength in recipient muscle groups; however, there was greater variation in the results of larger case series. The best, most consistent outcomes were demonstrated for restoration of wrist/finger extension and elbow extension.

CONCLUSIONS

Motor nerve transfers are a promising treatment option to restore upper-extremity function after SCI. Flexor reinnervation strategies show variable treatment effect sizes; however, extensor reinnervation may provide more consistent, meaningful recovery. Despite numerous published case reports describing good patient outcomes with nerve transfers, there remains a paucity in the literature regarding optimal timing and long-term clinical outcomes with these procedures.

Nerve transfers in the upper extremity following cervical spinal cord injury. Part 2: Preliminary results of a prospective clinical trial

OBJECTIVE

Patients with cervical spinal cord injury (SCI)/tetraplegia consistently rank restoring arm and hand function as their top functional priority to improve quality of life. Motor nerve transfers traditionally used to treat peripheral nerve injuries are increasingly used to treat patients with cervical SCIs. In this article, the authors present early results of a prospective clinical trial using nerve transfers to restore upper-extremity function in tetraplegia.

METHODS

Participants with American Spinal Injury Association (ASIA) grade A-C cervical SCI/tetraplegia were prospectively enrolled at a single institution, and nerve transfer(s) was performed to improve upper-extremity function. Functional recovery and strength outcomes were independently assessed and prospectively tracked.

RESULTS

Seventeen participants (94.1% males) with a median age of 28.4 years (range 18.2-76.3 years) who underwent nerve transfers at a median of 18.2 months (range 5.2-130.8 months) after injury were included in the analysis. Preoperative SCI levels ranged from C2 to C7, most commonly at C4 (35.3%). The median postoperative follow-up duration was 24.9 months (range 12.0-29.1 months). Patients who underwent transfers to median nerve motor branches and completed 18- and 24-month follow-ups achieved finger flexion strength Medical Research Council (MRC) grade ≥ 3/5 in 4 of 15 (26.7%) and 3 of 12 (25.0%) treated upper limbs, respectively. Similarly, patients achieved MRC grade ≥ 3/5 wrist flexion strength in 5 of 15 (33.3%) and 3 of 12 (25.0%) upper limbs. Among patients who underwent transfers to the posterior interosseous nerve (PIN) for wrist/finger extension, MRC grade ≥ 3/5 strength was demonstrated in 5 of 9 (55.6%) and 4 of 7 (57.1%) upper limbs 18 and 24 months postoperatively, respectively. Similarly, grade ≥ 3/5 strength was demonstrated in 5 of 9 (55.6%) and 4 of 7 (57.1%) cases for thumb extension. No meaningful donor site deficits were observed. Patients reported significant postoperative improvements from baseline on upper-extremity-specific self-reported outcome measures.

CONCLUSIONS

Motor nerve transfers are a promising treatment option to restore upper-extremity function after SCI. In the authors' experience, nerve transfers for the reinnervation of hand and finger flexors showed variable functional recovery; however, transfers for the reinnervation of arm, hand, and finger extensors showed a more consistent and meaningful return of strength and function.

Nerve transfer surgery in cervical spinal cord injury: a qualitative study exploring surgical and caregiver participant experiences

PURPOSE

To investigate perceptions of surgical participants and their caregivers regarding novel nerve transfer surgery to restore upper extremity function in cervical level spinal cord injury.

MATERIALS AND METHODS

A qualitative study design was used. A multidisciplinary team developed semi-structured interview guides. Interviews were recorded, transcribed and analyzed using basic text analysis.

RESULTS

Participants had limited information about procedures to improve function after spinal cord injury. When discussing their choice to undergo nerve (as compared to traditional tendon) transfer surgery, they describe a desire to avoid post-operative immobilization. Barriers included the pre-operative testing, cost and inconvenience of travel for surgery, and understanding complex health information related to the procedure. While expectations matched descriptions of outcomes among participants and were generally positive, caregivers expressed disappointment. The long time interval for gains in function to be realized and relatively incremental gains achieved were frustrating to all.

CONCLUSIONS

People with cervical spinal cord injury and their caregivers need more information about options to restore function and about realistic range of improvements with treatment. Further work to mitigate barriers and develop health information materials around nerve transfer surgery may improve medical decision making around and appropriate use of this newer treatment option.IMPLICATIONS FOR REHABILITATIONNerve transfer surgery is a novel and acceptable means of improving upper extremity function in the setting of cervical spinal cord injury.People with cervical spinal cord injury and their caregivers need information about options to restore hand and arm function and mitigation of barriers around these treatment options.

Pectolinarigenin promotes functional recovery and inhibits apoptosis in rats following spinal cord injuries

Spinal cord injury (SCI) is a devastating neurological injury that frequently leads to neurological defects and disabilities. The only effective pharmacotherapy currently available is methylprednisolone (MP), which is controversial due to its high incidence of complications, adverse events and ultimately limited efficacy in SCI. Therefore, the development of alternative therapeutic agents for the treatment of SCI is of great clinical significance. In the present study, an acute SCI rat model was induced and, following a modified Allen method, the function of pectolinarigenin (PG) in SCI was investigated. A total of 36 rats were randomly divided into 6 groups (n=6 in each group); a sham surgery group and an SCI + saline group were used as negative controls and an SCI + MP (30 mg/kg) group was used as a positive control. The remaining animals were subdivided into three groups: SCI + PG (10 mg/kg); SCI + PG (30 mg/kg); and SCI + PG (50 mg/kg). Basso-Beattie-Bresnahan locomotor rating scoring was performed to assess functional recovery. Nissl staining and TUNEL staining were used to evaluated neuronal lesion volume and apoptosis, respectively. The results demonstrated that PG significantly improved functional recovery and reduced tissue loss, and neuronal apoptosis. Furthermore, a western blotting assay was conducted to measure the expression of genes associated with apoptosis. The data suggested that PG downregulated the activated caspase-3, caspase-9 and poly-ADP-ribose polymerase expression and reduced the Bax: Bcl2 ratio. The findings of the present study suggested that PG may exert a protective effect against SCI in rats, potentially by inhibiting neuronal apoptosis and PG may therefore serve as a novel therapeutic agent against SCI.

Protective distal side-to-side neurorrhaphy in proximal nerve injury-an experimental study with rats

Background

Side-to-side neurorrhaphy may protect the denervated end organ and preserve the initial connection with proximal stump. We examined the effect of protective side-to-side anastomosis on nerve and end organ regeneration in proximal nerve injury model.

Methods

The left common peroneal nerve of 24 Sprague Dawley rats was proximally transected. In groups B and C, side-to-side neurorrhaphy was performed distally between the peroneal and tibial nerves without (group B) and with (group C) partial donor nerve axotomy inside the epineural window. Group A served as an unprotected control. After 26 weeks, the proximal transection was repaired with end-to-end neurorrhaphy on all animals. Regeneration was followed during 12 weeks with the walk track analysis. Morphometric studies and wet muscle mass calculations were conducted at the end of the follow-up period.

Results

The results of the walk track analysis were significantly better in groups B and C compared to group A. Groups B and C showed significantly higher wet mass ratios of the tibialis anterior and extensor digitorum longus muscle compared to group A. Group C showed significantly higher morphometric values compared to group A. Group B reached higher values of the fibre count, fibre density, and percentage of the fibre area compared to group A.

Conclusions

Protective distal side-to-side neurorrhaphy reduced muscle atrophy and had an improving effect on the morphometric studies and walk track analysis. Distal side-to-side neurorrhaphy does not prevent the regenerating axons to grow from the proximal stump to achieve distal nerve stump.

Double Motor Nerve Transfer for All Finger Flexion in Cervical Spinal Cord Injury: An Anatomical Study and a Clinical Report

PURPOSE

To explore the feasibility of restoring all finger flexion after a cervical spinal cord injury.

METHODS

Double nerve transfer was conducted in 22 cadaver upper extremities. Donor nerves were the brachialis branch of the musculocutaneous nerve and the extensor carpi radialis brevis (ECRB) branches of the radial nerve. Recipient nerves were the anterior interosseous nerve (AIN) and the flexor digitorum profundus (FDP) branch of ulnar nerve (ulnar-FDP). Nerve transfers were evaluated on 3 parameters: surgical feasibility, donor-to-recipient axon count ratio, and distance from the coaptation site to the muscle entry of recipient nerve. A complete C6 spinal cord injury reconstruction was accomplished in a patient using a double nerve transfer of ECRB to ulnar-FDP and brachialis to AIN.

RESULTS

In the cadaver study, nerve transfers from ECRB to AIN, brachialis to AIN, and ECRB to ulnar-FDP were all feasible. The transfer from the brachialis to ulnar-FDP was not possible. Mean myelinated axon counts of AIN, brachialis, ulnar-FDP, and ECRB were 2,903 ± 1049, 1,497 ± 606, 753 ± 364, and 567 ± 175, respectively. The donor-to-recipient axon count ratios of ECRB to AIN, brachialis to AIN, and ECRB to ulnar-FDP were 0.24 ± 0.15, 0.55 ± 0.38, and 0.98 ± 0.60, respectively. The distance from coaptation of the ECRB to the ulnar-FDP muscle entry was shorter than for the other nerve transfers (54 ± 14.29 mm). At 18 months, there was restoration of flexion in all fingers and functional improvement from double nerve transfer of the brachialis to the AIN and the ECRB to the ulnar-FDP.

CONCLUSIONS

Restoration of all finger flexion may be feasible by the ECRB to ulnar-FDP and brachialis to AIN double nerve transfer.

CLINICAL RELEVANCE

Double nerve transfer can be used in C6-C7 spinal cord injury and patients with lower arm-type brachial plexus injury who have no finger flexion but have good brachialis and ECRB.

Salvage of cervical motor radiculopathy using peripheral nerve transfer reconstruction

Purpose: Motor nerve transfer surgery involves re-innervation of important distal muscles using either an expendable motor branch or a fascicle from an adjacent functioning nerve. This technique is established as part of the reconstructive algorithm for traumatic brachial plexus injuries. The reproducible outcomes of motor nerve transfer surgery have resulted in exploration of the application of this technique to other paralysing conditions. The objective of this study is to report feasibility and increase awareness about nerve transfer as a method of improving upper limb function in patients with cervical motor radiculopathy of different aetiology. Results: In this case series we report 3 cases with different modes of injury to the spinal nerve roots with significant and residual motor radiculopathy that have been successfully treated with nerve transfer surgery with good functional outcomes. The cases involved iatrogenic nerve root injury, tumour related root compression and degenerative root compression. Conclusion: Nerve transfer surgery may offer reliable reconstruction for paralysis when there has been no recovery following a period of conservative management. However the optimum timing of nerve transfer intervention is not yet identified for patients with motor radiculopathy.

The Use of Nerve Transfers to Restore Upper Extremity Function in Cervical Spinal Cord Injury

BACKGROUND

Nerve transfer surgery to restore upper extremity function in cervical spinal cord injury (SCI) is novel and may transform treatment. Determining candidacy even years post-SCI is ill defined and deserves investigation.

OBJECTIVE

To develop a diagnostic algorithm, focusing on electrodiagnostic (EDX) studies, to determine eligibility for nerve transfer surgery.

DESIGN

Retrospective descriptive case series.

SETTING

Tertiary university-based institution.

PATIENTS

Individuals with cervical SCI (n = 45).

METHODS

The electronic medical records of people referred to the Plastic Surgery Multidisciplinary Upper Extremity Surgery in SCI clinic from 2010-2015 were reviewed. People were considered for nerve transfers to restore elbow extension or finger flexion and/or extension. Data including demographic, clinical evaluation, EDX results, surgery, and outcomes were collected and analyzed.

MAIN OUTCOME MEASUREMENTS

EDX data, including nerve conduction studies and electromyography, for bilateral upper extremities of each patient examined was used to assess for the presence of lower motor neuron injury, which would preclude late nerve transfer.

RESULTS

Based on our criteria and the results of EDX testing, a substantial number of patients presenting even years post-SCI were candidates for nerve transfers. Clinical outcome results are heterogeneous but promising and suggest that further refinement of eligibility, long-term follow-up, and standardized assessment will improve our understanding of the role of nerve transfer surgery to restore function in people with midcervical SCI.

CONCLUSIONS

Many patients living with SCI are candidates for nerve transfer surgery to restore upper extremity function. Although the ultimate efficacy of these surgeries is not yet determined, this study attempts to report the criteria we are using and may ultimately determine the timing for intervention and which transfers are most useful for this heterogeneous population.

LEVEL OF EVIDENCE

IV.