Compressive Neuropathies of the Upper Extremity: Anatomy for the Peripheral Nerve Surgeon.

Advance knowledge of anatomy is a prerequisite for the peripheral nerve surgeon. This article serves to provide an outline of anatomic regions where nerve entrapment or compression can occur. Each section is subdivided into anatomic regions where the etiology, indications, and relevant and aberrant anatomy are discussed, as well as common surgical approaches to the problematic anatomic site. The purpose is to provide an overview for the peripheral nerve surgeon and offer a valuable resource to provide a better understanding and optimal care for this patient population.

Effects of robot-assisted upper limb training combined with functional electrical stimulation in stroke patients: study protocol for a randomized controlled trial.

INTRODUCTION: About 17-80% stroke survivors experience the deficit of upper limb function, which strongly influences their independence and quality of life. Robot-assisted training and functional electrical stimulation are commonly used interventions in the rehabilitation of hemiplegia upper extremities, while the effect of their combination remains unclear. The aim of this trial is to explore the effect of robot-assisted upper limb training combined with functional electrical stimulation, in terms of neuromuscular rehabilitation, compared with robot-assisted upper limb training alone. METHODS: Individuals (n = 60) with the first onset of stroke (more than 1 week and less than 1 year after stroke onset) will be considered in the recruitment of this single-blinded, three-arm randomized controlled trial. Participants will be allocated into three groups (robot-assisted training combined with functional electrical stimulation group, robot-assisted training group, and conventional rehabilitation therapies group) with a ratio of 1:1:1. All interventions will be executed for 45 min per session, one session per day, 5 sessions per week for 6 weeks. The neuromuscular function of the upper limb (Fugl-Meyer Assessment of upper extremity), ability of daily life (modified Barthel Index), pain (visual analogue scale), and quality of life (EQ-5D-5L) will be assessed at the baseline, at the end of this trial and after 3 months follow-up. Two-way repeated measures analysis of variance will be used to compare the outcomes if the data are normally distributed. Simple effects tests will be used for the further exploration of interaction effects by time and group. Scheirer-Ray-Hare test will be used if the data are not satisfied with normal distribution. DISCUSSION: We expect this three-arm randomized controlled trial to explore the effectiveness of robot-assisted training combined with functional electrical stimulation in improving post-stroke upper limb function compared with robot-assisted training alone. TRIAL REGISTRATION: Effect of upper limb robot on improving upper limb function after stroke, identifier: ChiCTR2300073279. Registered on 5 July 2023.

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.

Upper-limb neurovascular compression, pectoralis minor and quadrilateral space syndromes: A narrative review of current literature.

Pectoralis minor syndrome (PMS) and quadrilateral space syndrome (QSS) are uncommon neurovascular compression disorders affecting the upper extremity. PMS involves compression under the pectoralis minor muscle, and QSS results from compression in the quadrilateral space-both are classically observed in overhead-motion athletes. Diagnosing PMS and QSS may be challenging due to variable presentations and similarities with other, more common, upper-limb pathologies. Although there is no gold standard diagnostic, local analgesic muscle-block response in a patient with the appropriate clinical context is often all that is required for an accurate diagnosis after excluding more common etiologies. Treatment ranges from conservative physical therapy to decompressive surgery, which is reserved for refractory cases or severe, acute vascular presentations. Decompression generally yields favorable outcomes, with most patients experiencing significant relief and restored baseline function. In conclusion, PMS and QSS, although rare, can cause debilitating upper-extremity symptoms; accurate diagnosis and appropriate treatment offer excellent outcomes, alleviating pain and disability.

Timing of surgery in peripheral nerve injury of the upper extremity.

Peripheral nerve injuries present a complex clinical challenge, requiring a nuanced approach in surgical management. The consequences of injury vary, with sometimes severe disability, and a risk of lifelong pain for the individual. For late management, the choice of surgical techniques available range from neurolysis and nerve grafting to tendon and nerve transfers. The choice of technique utilized demands an in-depth understanding of the anatomy, patient demographics and the time elapsed since injury for optimized outcomes. This paper focuses on injuries to the radial, median and ulnar nerves, outlining the authors' approach to these injuries.Level of evidence: IV.

The 2-by-2 Inch "Key Window" in the Upper Extremity: An Anatomical Appraisal of the Accessibility and Proximity of the Major Nerves and Vessels.

BACKGROUND: The brachial plexus is a network of nerves located between the neck and axilla, which receives input from C5-T1. Distally, the nerves and blood vessels that supply the arm and forearm form a medial neurovascular bundle. The purpose of this study was to illustrate that a peripheral nerve dissection via a 2 × 2 inch window would allow for identification and isolation of the major nerves and blood vessels that supply the arm and forearm. METHODS: A right side formalin-fixed latex-injected cadaveric arm was transected at the proximal part of the axillary fold and included the scapular attachments. Step-by-step anatomical dissection was carried out and documented with three-dimensional digital imaging. RESULTS: A 2 × 2 inch window centered 2 inches distal to the axillary fold on the medial surface of the arm enabled access to the major neurovascular structures of the arm and forearm: the median nerve, ulnar nerve, medial antebrachial cutaneous nerve, radial nerve and triceps motor branches, musculocutaneous nerve and its biceps and brachialis branches and lateral antebrachial cutaneous nerve, basilic vein and brachial artery and vein, and profunda brachii artery. CONCLUSIONS: Our study demonstrates that the majority of the neurovascular supply in the arm and forearm can be accessed through a 2 × 2 inch area in the medial arm. Although this "key window" may not be entirely utilized in the operative setting, our comprehensive didactic description of peripheral nerve dissection in the cadaver laboratory can help in safer identification of complex anatomy encountered during surgical procedures.

State of the art review. Upper extremity revision nerve compression surgery.

Although surgical release of upper extremity nerve compression syndromes is highly effective, persistence or recurrence of symptoms and signs may occur. Thorough investigation is necessary in this situation before treatment is recommended. If the symptoms cannot be explained by other pathology than compression of the affected nerve and if conservative management has not provided improvement, reoperation may be considered. This review provides an overview of the diagnostic and surgical considerations in the revision of carpal tunnel syndrome, cubital tunnel syndrome and thoracic outlet syndrome.Level of evidence: V.

Trends and insights review. Nerve procedures in the management of upper limb spasticity.

This article reviews the recent advances or nerve-oriented surgical procedures in the treatment of the spastic upper limb. The idea to intervene on the nerve is not recent, but new trends have developed in nerve surgery over the past few years, stimulating experiments and research. Specific surgical procedures involving the nerves have been described at different levels from proximal to distal: at the cervical spinal cord and the dorsal root entry zone (rhizotomy), at the level of the roots (contralateral C7 transfer) or in the peripheral nerve, within the motor trunk (selective neurectomy) or as its branches penetrate the muscles (hyperselective neurectomy). All of these neurosurgical procedures are only effective on spasticity but do not address the other deformities, such as contractures and motor deficit. Additional procedures may have to be planned in conjunction with nerve procedures to optimize outcomes.

Targeted muscle reinnervation in bionic upper limb reconstruction: current status and future directions.

Selective nerve transfers are used in the setting of upper limb amputation to improve myoelectric prosthesis control. This surgical concept is referred to as targeted muscle reinnervation (TMR) and describes the rerouting of the major nerves of the arm onto the motor branches of the residual limb musculature. Aside from providing additional myosignals for prosthetic control, TMR can treat and prevent neuroma pain and possibly also phantom limb pain. This article reviews the history and current applications of TMR in upper limb amputation, with a focus on practical considerations. It further explores and identifies technological innovations to improve the man-machine interface in amputation care, particularly regarding implantable interfaces, such as muscle electrodes and osseointegration. Finally, future clinical directions and possible scientific avenues in this field are presented and critically discussed.

Distal nerve transfers for peripheral nerve injuries: indications and outcomes.

Distal nerve transfer is a refined surgical technique involving the redirection of healthy sacrificable nerves from one part of the body to reinstate function in another area afflicted by paralysis or injury. This approach is particularly valuable when the original nerves are extensively damaged and standard repair methods, such as direct suturing or grafting, may be insufficient. As the nerve coaptation is close to the recipient muscles or skin, distal nerve transfers reduce the time to reinnervation. The harvesting of nerves for transfer should usually result in minimal or no donor morbidity, as any anticipated loss of function is compensated for by adjacent muscles or overlapping cutaneous territory. Recent years have witnessed notable progress in nerve transfer procedures, markedly enhancing the outcomes of upper limb reconstruction for conditions encompassing peripheral nerve, brachial plexus and spinal cord injuries.

Just the facts: brachial plexus blocks for upper extremity injuries in the emergency department.

Ultrasound-guided nerve blocks (UGNBs) are becoming a more common method for pain control in the emergency department. Specifically, brachial plexus blocks have shown promise for acute upper extremity injuries as well as an alternative to procedural sedation for glenohumeral reductions. Unfortunately, there is minimal discussion in the EM literature regarding phrenic nerve paralysis (a well-known complication from brachial plexus blocks). The anatomy of the brachial plexus, its relationship to the phrenic nerve, and why ultrasound-guided brachial plexus blocks can cause phrenic nerve paralysis and resultant respiratory impairment will be discussed. The focus on patient safety is paramount, and those with preexisting respiratory conditions, extremes of age or weight, spinal deformities, previous neck injuries, and anatomical variations are at greater risk. We put forth different block strategies for risk mitigation, including patient selection, volume and type of anesthetic, block location, postprocedural monitoring, and specific discharge instructions. Understanding the benefits and risks of UGNBs is critical for emergency physicians to provide effective pain control while ensuring optimal patient safety.

The changes of neuroactivity of Tui Na (Chinese massage) at Hegu acupoint on sensorimotor cortex in stroke patients with upper limb motor dysfunction: a fNIRS study.

BACKGROUND: Tui Na (Chinese massage) is a relatively simple, inexpensive, and non-invasive intervention, and has been used to treat stroke patients for many years in China. Tui Na acts on specific parts of the body which are called meridians and acupoints to achieve the role of treating diseases. Yet the underlying neural mechanism associated with Tui Na is not clear due to the lack of detection methods. OBJECTIVE: Functional near-infrared spectroscopy (fNIRS) was used to explore the changes of sensorimotor cortical neural activity in patients with upper limb motor dysfunction of stroke and healthy control groups during Tui Na Hegu Point. METHODS: Ten patients with unilateral upper limb motor dysfunction after stroke and eight healthy subjects received Tui Na. fNIRS was used to record the hemodynamic data in the sensorimotor cortex and the changes in blood flow were calculated based on oxygenated hemoglobin (Oxy-Hb), the task session involved repetitive Tui Na on Hegu acupoint, using a block design [six cycles: rest (20 seconds); Tui Na (20 seconds); rest (30 seconds)]. The changes in neural activity in sensorimotor cortex could be inferred according to the principle of neurovascular coupling, and the number of activated channels in the bilateral hemisphere was used to calculate the lateralization index. RESULT: 1. For hemodynamic response induced by Hegu acupoint Tui Na, a dominant increase in the contralesional primary sensorimotor cortex during Hegu point Tui Na of the less affected arm in stroke patients was observed, as well as that in healthy controls, while this contralateral pattern was absent during Hegu point Tui Na of the affected arm in stroke patients. 2. Concerning the lateralization index in stroke patients, a significant difference was observed between lateralization index values for the affected arm and the less affected arm (P < 0.05). Wilcoxon tests showed a significant difference between lateralization index values for the affected arm in stroke patients and lateralization index values for the dominant upper limb in healthy controls (P < 0.05), and no significant difference between lateralization index values for the less affected arm in stroke patients and that in healthy controls (P = 0.36). CONCLUSION: The combination of Tui Na and fNIRS has the potential to reflect the functional status of sensorimotor neural circuits. The changes of neuroactivity in the sensorimotor cortex when Tui Na Hegu acupoint indicate that there is a certain correlation between acupoints in traditional Chinese medicine and neural circuits.

Block performance indices of perivascular and perineural techniques of ultrasound-guided axillary block in upper limb surgeries: A comparative study.

Background: Nerve block anesthesia is a common regional anesthesia used for upper limb surgeries because of its ability to target the operative site and provision of impressive postanesthetic pain relief. This randomized, single-blinded study compared the quality of block of the perineural (PN) and perivascular (PV) techniques of axillary brachial plexus block under ultrasound guidance. Methods: Sixty-six participants were recruited into either PV or PN groups. The local anesthetic (LA) comprised 14 ml of 0.5% bupivacaine, 14 ml of 1% lidocaine, and 2 ml of dexmedetomidine (50 µg/ml). Under ultrasound guidance, 6 ml of LA was deposited around the musculocutaneous nerve for both groups. For the PV group, 24 ml was deposited dorsal to the axillary artery while 8 ml each was deposited around median, radial, and ulnar nerves for the PN group. Results: The mean total procedure time in PN group was significantly longer than in the PV group (7.82 ± 0.95 min vs. 4.79 ± 1.11 min; P = 0.001). Participants in the PN group required more needle passes (66.7% required 4 passes while 81.8% required only 2 passes in the PV group). The success rate was 100% in PN group and 93.9% in PV group (P = 0.49). Conclusion: The PV and PN techniques were comparable in terms of their success rates and total anesthesia-related times. The PN technique had higher success rate and faster block onset, but the PV provided a quicker performance time and fewer needle passes. Hence, PV technique may be preferable to PN for high-volume surgical units.

Résumé Contexte: L'anesthésie par bloc nerveux est une anesthésie régionale courante utilisée pour les chirurgies des membres supérieurs en raison de sa capacité à cibler le site opératoire et à fournir un soulagement impressionnant de la douleur postanesthésique. Cette étude randomisée à un seul insu a comparé la qualité des techniques de blocage périneural (NP) et périvasculaire (PV) du plexus brachial axillaire sous guidage échographique. Méthodes: Soixante-six participants ont été recrutés dans les groupes PV ou PN. L'anesthésie locale (AL) comprenait 14 ml de bupivacaïne à 0,5 %, 14 ml de lidocaïne à 1 % et 2 ml de dexmedetomidine (50 µg/ml). Sous la direction des ultrasons, 6 ml de LA ont été déposés autour du nerf musculo-cutané pour les deux groupes. Pour le groupe PV, 24 ml ont été déposés en position dorsale par rapport à l'artère axillaire, tandis que 8 ml ont été déposés autour des nerfs médian, radial et ulnaire pour le groupe PN. Résultats: La durée totale moyenne de la procédure dans le groupe PN était significativement plus longue que dans le groupe PV (7,82 ± 0,95 min contre 4,79 ± 1,11 min ; P = 0,001). Les participants du groupe PN ont exigé plus de passes d'aiguille (66,7 % ont exigé 4 passes, tandis que 81,8 % n'ont exigé que 2 passes dans le groupe PV). Le taux de réussite était de 100 % dans le groupe PN et de 93,9 % dans le groupe PV (P = 0,49). Conclusion: Les techniques PV et PN étaient comparables en termes de taux de réussite et de temps total liés à l'anesthésie. La technique PN a eu un taux de succès plus élevé et un début de bloc plus rapide, mais la PV a fourni un temps de performance plus rapide et moins de passes d'aiguille. Par conséquent, la technique PV peut être préférable à la PN pour les unités chirurgicales à volume élevé. Mots-clés: Bloc nerveux, périneural, périvasculaire.

[Ultrasound examination of nerves of the upper extremities]. / Nervensonographie der oberen Extremitäten.

The ultrasound examination of peripheral nerves has been further developed in recent years and is recognized as an independent discipline by the German Society of Ultrasound in Medicine (DEGUM). A systematic ultrasound examination of the musculoskeletal system is not limited to the joints, muscles and bones but should also include the examination of nerves and blood vessels. Therefore, in the practice of ultrasound examination every rheumatologist should have at least a basic knowledge of the ultrasound examination of the peripheral nerves. In this article the authors present a landmark-based concept in which the three large nerves of the upper extremities can be completely visualized from proximal to distal and evaluated.

Anatomical Variants of the Upper Limb Nerves: Clinical and Preoperative Relevance.

Profound knowledge of nerve variations is essential for clinical practice. It is crucial for interpreting the large variability of a patient's clinical presentation and the different mechanisms of nerve injury. Awareness of nerve variations facilitates surgical safety and efficacy. Clinically significant anatomical variations can be classified into two main groups: variability in the course of the nerve and variability of structures surrounding the nerve. In this review article we focus on the most common nerve variants of the upper extremity and their clinical relevance.

Upper limb nerve variations may alter clinical diagnosis: a scoping review / Las variaciones nerviosas del miembros superior pueden alterar el diagnóstico clínico: una revisión de alcance

SUMMARY: Upper limb nerve variations may be related to the absence of a nerve, an interconnection between two nerves or a variant course. The purpose of this review is to screen the existing literature on upper limb nerve variations that may alter the neurologic diagnostic process. A scoping review was performed following PRISMA for Scoping Reviews guidelines. Initially, 1331 articles were identified by searching Pubmed and Web of Science until the 22nd of October 2022. After screening, reading, and additional searching 50 articles were included in this review. Variations were divided into two categories: 1) variations causing a different innervation pattern involving sensory, motor, or both types of fibers, and 2) variations causing or related to compression syndromes. Two-thirds of the included articles were cadaver studies. Nine articles were diagnostic studies on symptomatic or healthy individuals involving medical imaging and/or surgery. Nerve variations that may cause a different innervation pattern concern most frequently their interconnection. The connection between the median and musculocutaneous nerve in the upper limb and the connection between the median and ulnar nerve in the forearm (Martin-Gruber) or hand (Riche-Cannieu) may be present in half of the population. Injury to these connections may cause compound peripheral neuropathies a result of variant sensory and motor branching patterns. Muscular, vascular, or combined anomalies in the forearm were reported as causes of entrapment neuropathies. These nerve variations may mimic classical entrapment syndromes such as carpal tunnel syndrome or compression at ulnar canal (Guyon's canal). Knowledge of frequent nerve variations in the arm may be important during the diagnostic process and examination. Variant innervation patterns may explain non-classical clinical signs and/or symptoms during provocative tests. Classical nerve compression syndromes in the arm may warrant for differential diagnosis, especially in the case of persistent or recurrent symptoms.

Las variaciones nerviosas del miembro superior pueden estar relacionadas con la ausencia de un nervio, una interconexión entre dos nervios o un curso variante. El objetivo de esta revisión fue examinar la literatura existente sobre las variaciones de los nervios de los miembros superiores que pueden alterar el proceso de diagnóstico neurológico. Se realizó una revisión de alcance siguiendo las pautas de PRISMA para revisiones de alcance. Inicialmente, se identificaron 1331 artículos mediante la búsqueda en Pubmed y Web of Science hasta el 22 de octubre de 2022. Después de la selección, la lectura y la búsqueda adicional, se incluyeron 50 artículos en esta revisión. Las variaciones se dividieron en dos categorías: 1) variaciones que causan un patrón de inervación diferente que involucra fibras sensoriales, motoras o de ambos tipos, y 2) variaciones que causan o están relacionadas con síndromes de compresión. Dos tercios de los artículos incluidos eran estudios de cadáveres. Nueve artículos fueron estudios de diagnóstico en individuos sintomáticos o sanos que involucraron imágenes médicas y/o cirugía. Las variaciones nerviosas que pueden causar un patrón de inervación diferente se refieren con mayor frecuencia a su interconexión. La conexión entre el nervio mediano y musculocutáneo en el miembro superior y la conexión entre el nervio mediano y ulnar en el antebrazo (Martin-Gruber) o la mano (Riche-Cannieu) puede estar presente en la mitad de la población. La lesión de estas conexiones puede causar neuropatías periféricas compuestas como resultado de patrones de ramificación variantes sensitivos y motores. Se informaron anomalías musculares, vasculares o combinadas en el antebrazo como causas de neuropatías por atrapamiento. Estas variaciones nerviosas pueden imitar los síndromes de atrapamiento clásicos, como el síndrome del túnel carpiano o la compresión en el canal ulnar. El conocimiento de las variaciones nerviosas frecuentes en el brazo puede ser importante durante el proceso de diagnóstico y examen. Los patrones de inervación variantes pueden explicar los signos y/o síntomas clínicos no clásicos durante las pruebas de provocación. Los síndromes clásicos de compresión nerviosa en el brazo pueden justificar el diagnóstico diferencial, especialmente en el caso de síntomas persistentes o recurrentes.

Nerve Compression Syndromes of the Upper Extremity.

Nerve compression syndromes of the upper extremity are among the most common pathologies encountered in orthopaedic surgery. Symptoms can be debilitating for patients-affecting their work, activity level, sleep patterns, and overall quality of life. The community orthopaedic specialist should be familiar with the anatomy, etiology, and presentation of upper extremity nerve entrapment. Furthermore, knowledge of current evidence surrounding the management of these common syndromes can prove valuable for treating clinicians. Treatment ranges from nonsurgical (including medication and splinting) to surgical (when symptoms are severe). Although the gold standard treatment for nerve compression syndromes of the upper extremity is typically surgical release, nonsurgical methods should also be reviewed and understood because these can play an important role for patients as well. Community orthopaedic specialists should be well aware of the risks and complications associated with surgical releases.

Value of ultrasound assessment for traumatic nerve injury of the upper limb.

AIM OF WORK: The type of traumatic peripheral nerve injury is a key factor for determining optimal treatment. Proper assessment of peripheral nerve injury facilitates appropriate treatment, significantly affects prognosis, and reduces disabilities. This study evaluated ultrasonography (US) to assess upper limb traumatic nerve injuries and compared the US with electrodiagnostic studies as the gold standard. MATERIALS AND METHODS: Participants were 69 adults (57 [83%] men, 12 [17%] women; mean age 36.3 ± 13.5 years) with a total of 96 peripheral nerve injuries (duration of 1 month-3 years). High-frequency US examinations and electro-physiologic studies confirmed upper limb peripheral nerve injury. RESULTS: Nerve discontinuation was diagnosed in 15 (15.6%) nerves; the cross-sectional area was increased in 33 (34.4%) nerves. Of 96 injuries, 54 (56.3%) were median, 24 (25%) were ulnar, and 18 (18.8%) were radial nerves. No statistically significant difference was found between US and electro-physiologic studies for nerve injury diagnosis (p = 0.054). CONCLUSION: No significant differences were found between US and electro-physiologic studies for diagnosis of nerve injuries; however, US was valuable to assess surrounding tissue and supplied muscles. The capabilities to detect nerve injury and associated distal muscular, vascular, and other regional structures position the US as a complementary diagnostic tool.