Nerve Transfer Surgery for Penetrating Upper Extremity Injuries

Evaluating motor unit properties after nerve transfer surgery

Nerve transfer surgery (NTS) shows promise in restoring movement to muscles paralyzed by spinal cord (SCI) and peripheral nerve injury (PNI). Yet, motor outcomes vary, and the neurophysiological factors influencing responders and non-responders remain unclear. As the fundamental goal of NTS is to reinnervate paralyzed muscles by creating new motor units (MUs), we examined MU properties after NTS for individuals with SCI and PNI. Nine participants (3 SCI, 6 PNI, 50.3 ± 13.9 years) >18 months post-NTS were evaluated and compared to either age-matched controls (SCI) or the contralateral limb (PNI). We used a sophisticated, signal processing software known as Decomposition-Based Quantitative Electromyography (DQEMG) and near-fiber EMG to examine MU characteristics sampled from needle electromyography signals recorded during low-intensity contractions. The NTS muscle MU potentials (MUP) were larger, and near-fiber MUPs (NFM) were more temporal dispersed than controls. Measures of neuromuscular junction instability were greater in NTS muscles compared to controls (p < 0.05). Firing rates of MU, and MUP phases and turns were not different between groups (p > 0.05). Overall, these data suggest the quality of reinnervation post-surgery requires further investigation as a potential mediator of motor outcome and the required time for successful reinnervation may be longer than currently predicted.

Repair methods in peripheral nerves after traumatic injuries: a systematic literature review

PURPOSE

To identify and describe the most used surgical repair methods for traumatic injuries to peripheral nerves, as well as highlight the causes of trauma to peripheral nerves and the most prevalent traumatized nerves.

METHODS

This is a systematic literature review using the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The searches were carried out in PubMED, in the time window from January 2018 to December 2022.

RESULTS

In total, 3,687 articles were collected, of which, after applying the inclusion and exclusion filters and analyzing the risk of bias, 34 articles remained. It was observed that the age of the injury and type of nerve repair strongly influence the recovery of patients. The most identified trauma repair procedures were neurolysis, direct suturing, grafting, and nerve transfer. Among these four procedures, direct suturing is currently preferred.

CONCLUSION

Several repair methods can be used in peripheral nerve injuries, with emphasis on direct suturing. However, nerve transfer proves to be a differential in those cases in which repair is delayed or the first treatment options have failed, which shows that each method will be used according to the indication for each case.

Single versus double fascicular transfer for brachial plexus injuries: a systematic review and meta-analysis with meta-regression

The primary objective of this review was to assess whether double fascicular transfer has superior outcomes compared with single fascicular transfer for reanimation of elbow flexion. In total, 58 studies including 1388 patients (mean age 29 years [SD 8]) were included. Subgroup analysis comparing the severity of brachial plexus injury (C5-C6, C5-C7, C5-C8) showed no significant difference in the recovery of MRC grade 3 and 4. The aggregated mean Disabilities of Arm, Shoulder and Hand score was 38 for the single fascicular transfer group and 27 for the double fascicular transfer group. Meta-regression controlling for level of injury showed that double fascicular transfer and C5-C6 injury were significant predictors of achieving MRC grade 3, while double fascicular transfer and shorter duration of surgical delay were significant predictors of achieving MRC grade 4. When controlling for the level of injury, double fascicular transfer is associated with a greater likelihood of achieving MRC grade 3 and 4 compared to single fascicular transfer. Overall donor site morbidity was not significantly different between single fascicular transfer and double fascicular transfer.

The trapezius plane block: Extended use in perioperative pain management in nerve transfer surgeries

Nerve transfer surgery has emerged as a promising approach to restoring function in paralyzed muscles. The trapezius plane block (TPB) blocks the thoracic branches of the posterior primary rami, providing extended analgesia in nerve transfer surgeries. The case report describes the analgesia profiling of a young man who suffered a traumatic pan-brachial plexus injury and underwent a spinal accessory nerve to the suprascapular nerve transfer. TPB was utilized as a part of multimodal analgesia. TPB represents an advancement in regional anesthesia, providing extended analgesia and reducing opioid consumption. TPB can promote patient comfort and facilitate early mobilization.

From Conservative Measures to Surgical Interventions, Treatment Approaches for Cubital Tunnel Syndrome: A Comprehensive Review

Cubital tunnel syndrome (CuTS) is a neuropathic condition characterized by the compression or irritation of the ulnar nerve at the elbow, resulting in a wide spectrum of symptoms ranging from pain and numbness to muscle weakness and impaired hand function. This comprehensive review delves into the diverse landscape of CuTS treatment approaches, emphasizing the importance of early intervention. The review explores how these strategies aim to alleviate symptoms and enhance patient well-being by beginning with conservative measures encompassing rest, splinting, medications, physical therapy, and lifestyle adjustments. Non-surgical medical interventions, including nerve gliding exercises, ultrasound-guided nerve injections, and orthotic devices, are considered alternative therapies for symptom relief. Surgical interventions, such as decompression procedures and emerging techniques, are discussed in detail, highlighting their indications and expected outcomes. Throughout this review, the critical role of patient-centered care is underscored, emphasizing the need for tailored treatment plans that respect individual preferences and goals. Recognizing the unique nature of each CuTS case, shared decision-making between patients and healthcare providers is advocated, ensuring that interventions align with specific patient needs. As research advances, promising developments in diagnosis, surgical techniques, and drug therapies offer hope for more effective management of CuTS, paving the way for improved symptom relief and enhanced nerve function.

Nerve Graft and Nerve Transfer for Improving Elbow Flexion in Children with Obstetric Palsy. A Systematic Review

Obstetric brachial plexus palsy is a rather common injury in newborns, caused by traction to the brachial plexus during labor. In this context, with the present systematic review, we aimed to explore the use of nerve graft and nerve transfer as procedures to improve elbow flexion in children with obstetric palsy. For the present review, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the MEDLINE, EMBASE, LILACS, The Cochrane Central Register of Controlled Trials, Web of Science, Wholis and SCOPUS databases. Predetermined criteria defined the following requirements for inclusion of a study: Clinical trials, quasi-experiments, and cohort studies that performed nerve graft and nerve transfer in children (≤ 3 years old) with diagnosis of obstetric palsy. The risk of bias in nonrandomized studies of interventions assessment tool was used for nonrandomized studies. Out of seven studies that used both procedures, three of them compared the procedures of nerve graft with nerve transfer, and the other four combined them as a reconstructive method for children with obstetric palsy. According to the Medical Research Council grading system, both methods improved equally elbow flexion in the children. Overall, our results showed that both techniques of nerve graft and nerve transfer are equally good options for nerve reconstruction in cases of obstetric palsy. More studies approaching nerve reconstruction techniques in obstetric palsy should be made, preferably randomized clinical trials, to validate the results of the present systematic review.

Peripheral Nerve Regeneration and Muscle Reinnervation

Injured peripheral nerves but not central nerves have the capacity to regenerate and reinnervate their target organs. After the two most severe peripheral nerve injuries of six types, crush and transection injuries, nerve fibers distal to the injury site undergo Wallerian degeneration. The denervated Schwann cells (SCs) proliferate, elongate and line the endoneurial tubes to guide and support regenerating axons. The axons emerge from the stump of the viable nerve attached to the neuronal soma. The SCs downregulate myelin-associated genes and concurrently, upregulate growth-associated genes that include neurotrophic factors as do the injured neurons. However, the gene expression is transient and progressively fails to support axon regeneration within the SC-containing endoneurial tubes. Moreover, despite some preference of regenerating motor and sensory axons to “find” their appropriate pathways, the axons fail to enter their original endoneurial tubes and to reinnervate original target organs, obstacles to functional recovery that confront nerve surgeons. Several surgical manipulations in clinical use, including nerve and tendon transfers, the potential for brief low-frequency electrical stimulation proximal to nerve repair, and local FK506 application to accelerate axon outgrowth, are encouraging as is the continuing research to elucidate the molecular basis of nerve regeneration.

Efficacy evaluation of personalized coaptation in neurotization for motor deficit after peripheral nerve injury: A systematic review and meta-analysis

INTRODUCTION

Peripheral neurotization, recently as a promising approach, has taken effect in recovering motor function after damage to a peripheral nerve root. Neural anastomosis comprised of nerve conduit and neurorrhaphy participates in the nerve reconstruction. Current literature lacks evidence supporting an individualized coaptation for rescue of locomotor loss in rat subjects with paraplegia secondary to peripheral nerve injury (PNI).

METHODS

This meta-analysis intends to qualify the specificity of gap-specific coaptation in treating a paralyzed limb following PNI. We used a highly sensitive search strategy to identify all published studies in multiple databases up to 1 May 2019. All identified trials were systematically evaluated using specific inclusion and exclusion criteria. Cochrane methodology was also applied to the results of this study.

RESULTS

Twelve studies, including 349 rat subjects, met eligibility criteria. For a medium nerve defect (0.5-3.0 cm), nerve conduit was more likely than neurorrhaphy to precipitate axon regeneration and improve motor outcome of the hemiplegic limb (OR = 3.61, 95% CI = 1.80, 7.26, p < .0003) at 3-month follow-up, whereas neurorrhaphy might take its place in promoting limb motor function in a small nerve gap (<0.5 cm) (OR = 0.48, 95% CI = 0.22, 1.07, p < .007). For a small nerve defect, nerve conduit still demonstrated visible effectiveness in recovery of limb motion albeit poorer than neurorrhaphy (OR = 1.50, 95% CI = 0.92, 2.47, p < .05).

CONCLUSION

Selective neurotization facilitates motor regeneration after nerve transection, and advisable choice of neural coaptation can maximize functional outcome on an individual basis.

Current Status of Therapeutic Approaches against Peripheral Nerve Injuries: A Detailed Story from Injury to Recovery

Peripheral nerve injury is a complex condition with a variety of signs and symptoms such as numbness, tingling, jabbing, throbbing, burning or sharp pain. Peripheral nerves are fragile in nature and can easily get damaged due to acute compression or trauma which may lead to the sensory and motor functions deficits and even lifelong disability. After lesion, the neuronal cell body becomes disconnected from the axon's distal portion to the injury site leading to the axonal degeneration and dismantlement of neuromuscular junctions of targeted muscles. In spite of extensive research on this aspect, complete functional recovery still remains a challenge to be resolved. This review highlights detailed pathophysiological events after an injury to a peripheral nerve and the associated factors that can either hinder or promote the regenerative machinery. In addition, it throws light on the available therapeutic strategies including supporting therapies, surgical and non-surgical interventions to ameliorate the axonal regeneration, neuronal survival, and reinnervation of peripheral targets. Despite the availability of various treatment options, we are still lacking the optimal treatments for a perfect and complete functional regain. The need for the present age is to discover or design such potent compounds that would be able to execute the complete functional retrieval. In this regard, plant-derived compounds are getting more attention and several recent reports validate their remedial effects. A plethora of plants and plant-derived phytochemicals have been suggested with curative effects against a number of diseases in general and neuronal injury in particular. They can be a ray of hope for the suffering individuals.