Superficial branch of the radial nerve regularly contains fibers from the lateral antebrachial cutaneous nerve: A role in neuroma treatment.

BACKGROUND: Many surgical strategies aim to treat the symptomatic neuroma of the superficial branch of the radial nerve (SBRN). It is still difficult to treat despite many attempts to reveal a reason for surgical treatment failure. The lateral antebrachial cutaneous nerve (LACN) is known to overlap and communicate with SBRN. Our study aims to determine the frequency of spreading of LACN fibers into SBRN branches through a microscopic dissection to predict where and how often LACN fibers may be involved in SBRN neuroma. METHODS: Eighty-seven cadaveric forearms were thoroughly dissected. The path of LACN fibers through the SBRN branching was ascertained using microscopic dissection. Distances between the interstyloid line and entry of LACN fibers into the SBRN and emerging and bifurcation points of the SBRN were measured. RESULTS: The LACN fibers joined the SBRN at a mean distance of 1.7 ± 2.5 cm proximal to the interstyloid line. The SBRN contained fibers from the LACN in 62% of cases. Most commonly, there were LACN fibers within the SBRN's third branch (59%), but they were also observed within the first branch, the second branch, and their common trunk (21%, 9.2%, and 22%, respectively). The lowest rate of the LACN fibers was found within the SBRN trunk (6.9%). CONCLUSION: The SBRN contains LACN fibers in almost 2/3 of the cases, therefore, the denervation of both nerves might be required to treat the neuroma. However, the method must be considered based on the particular clinical situation.

Superficial branch of the radial nerve passing through the supinator canal, emerging between the extensor digitorum and abductor pollicis longus muscles and consequently supplying the second finger and radial portion of the third finger: a case report and clinical implications.

Awareness of unique path of the superficial branch of the radial nerve and its unusual sensory distribution can help avoid potential diagnostic confusion. We present a unique case encountered during a routine dissection of a Central European male cadaver. An unusual course of the superficial branch of the radial nerve was found in the right forearm, where the superficial branch of the radial nerve originated from the radial nerve distally, within the supinator canal, emerged between the extensor digitorum and abductor pollicis longus muscles and supplied the second and a radial half of the third digit, featuring communications with the lateral antebrachial cutaneous nerve and the dorsal branch of the ulnar nerve. Due to dorsal emerging of the superficial branch of the radial nerve the dorsal aspect of the thumb was innervated by the lateral antebrachial cutaneous nerve. To our best knowledge such variation of the superficial branch of the radial nerve has never been reported before. This variation dramatically changes aetiology and manifestation of possible entrapment syndromes which clinicians should be aware of.

The communication patterns between the lateral antebrachial cutaneous nerve and the superficial branch of the radial nerve.

INTRODUCTION: The superficial branch of the radial nerve (SBRN) and the lateral antebrachial cutaneous nerve (LACN) are sensory nerves coursing within the forearm in a close relationship. This high degree of overlap and eventual communication between the nerves is of great surgical importance. The aim of our study is to identify the communication pattern and overlap of the nerves, to localize the position of this communication in relation to a bony landmark, and to specify the most common communication patterns. MATERIALS AND METHODS: One hundred and two adult formalin-fixed cadaveric forearms from 51 cadavers of Central European origin were meticulously dissected. The SBRN, as well as the LACN, were identified. The morphometric parameters concerning these nerves, as well as their branches and connections, were measured with a digital caliper. RESULTS: We have described the primary (PCB) and secondary communications (SCB) between the SBRN and the LACN and their overlap patterns. One hundred and nine PCBs were found in 75 (73.53%) forearms of 44 (86.27%) cadavers and fourteen SCBs in eleven hands (10.78%) of eight cadavers (15.69%). Anatomical and surgical classifications were created. Anatomically, the PCBs were classified in three different ways concerning: (1) the role of the branch of the SBRN within the connection; (2) the position of the communicating branch to the SBRN; and (3) the position of the LACN branch involved in the communication to the cephalic vein (CV). The mean length and width of the PCBs were 17.12 mm (ranged from 2.33 to 82.96 mm) and 0.73 mm (ranged from 0.14 to 2.01 mm), respectively. The PCB was located proximally to the styloid process of the radius at an average distance of 29.91 mm (ranged from 4.15 to 97.61 mm). Surgical classification is based on the localization of the PCBs to a triangular zone of the SBRN branching. The most frequent branch of the SBRN involved in the communication was the third (66.97%). Due to the frequency and position of the PCB with the third branch of the SBRN, the danger zone was predicted. According to the overlap between the SBRN and the LACN, we have divided 102 forearms into four types: (1) no overlap; (2) present overlap; (3) pseudo-overlap; and (4) both present and pseudo-overlap. Type 4 was the most common. CONCLUSION: The patterns of communicating branch arrangements appeared to be not just a rare phenomenon or variation, but rather a common situation highlighting clinical importance. Due to the close relationship and connection of these nerves, there is a high probability of simultaneous lesion.

Anatomical Assessment of Cephalic Vein and Superficial Branch of Radial Nerve Using High-Resolution Ultrasound Imaging.

Introduction The superficial branch of the radial nerve (SBRN) has a risk of nerve injury during cephalic vein (CV) cannulation. Due to the lack of imaging study regarding SBRN and CV relationship, we analyzed the anatomical relationship between the SBRN and the CV using ultrasound (US) imaging. Materials and Methods In total, 82 upper limbs of 41 healthy volunteers were analyzed. The SBRN and CV were identified at the following three points in the elbow extension and pronation position: at the radial styloid process (point 1), 5 cm proximal to point 1 (point 2), and 10 cm proximal to point 1 (point 3). Results The distance between the SBRN and CV was 1.1 ± 1.0 mm at point 1, 1.3 ± 1.3 mm at point 2, and 2.1 ± 1.6 mm at point 3. The depth of the SBRN from the surface of the skin was 2.7 ± 0.9 mm at point 1, 3.5 ± 1.1 mm at point 2, and 5.5 ± 1.9 mm at point 3. The percentage of the SBRN that ran beneath the CV was 17.5%, 53.5%, and 92.4% at points 1, 2, and 3, respectively. Conclusion Ultrasonography can reveal the anatomical relationship between the SBRN and CV.

The relationship between the lateral cutaneous antebrachial nerve and the superficial branch of the radial nerve and its impact on regional anesthetic and pain blocks of the thumb; What is more important: Nerves or dermatomes?

BACKGROUND: Innervation of the thumb and radial part of the dorsum of the hand is achieved primarily by the radial nerve, which is usually blocked for hand surgery. Inefficient blocks occur because the lateral antebrachial cutaneous nerve also extends into this area. The question then arises, whether skin innervation and peripheral blocking techniques should be directed at from the innervation by these nerves or more by the dermatome and its spinal segments. METHODS: In 68 human upper limbs embalmed with Thiel's method, the topography of the lateral antebrachial cutaneous nerve (LACN), the superficial branch of the radial nerve (sbRN) and communicating branch (CB) were investigated by meticulous dissection from the cubital fossa to the most distal macroscopically dissectible branch, and the areas reached by these nerves were compared to the described dermatome. RESULTS: In 52.9% of all specimens, the LACN was found proximal to the rascetta, in 35.3% it extended to the base of the thumb, and in 8 cases (11.8%) it extended distally to the base of the thumb. In 50%, the LACN was anterolateral to the brachioradialis muscle, and in 38.2%, strictly lateral. Only in 8 cases (11.8%) the LACN presented itself running more dorsally and laterally. A CB was observed in 28 specimens (41.2%). Both investigated nerves were found to innervate the dermatomes of C6 and C7. CONCLUSIONS: The LACN should be considered for individual targeted blocks for surgical procedures and pain therapy within the wrist and thumb region as all nerves that might contribute to innervation of a targeted dermatome should be blocked.

The Branching and Innervation Pattern of the Radial Nerve in the Forearm: Clarifying the Literature and Understanding Variations and Their Clinical Implications.

BACKGROUND: This study attempted to clarify the innervation pattern of the muscles of the distal arm and posterior forearm through cadaveric dissection. METHODS: Thirty-five cadavers were dissected to expose the radial nerve in the forearm. Each muscular branch of the nerve was identified and their length and distance along the nerve were recorded. These values were used to determine the typical branching and motor entry orders. RESULTS: The typical branching order was brachialis, brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, supinator, extensor digitorum, extensor carpi ulnaris, abductor pollicis longus, extensor digiti minimi, extensor pollicis brevis, extensor pollicis longus and extensor indicis. Notably, the radial nerve often innervated brachialis (60%), and its superficial branch often innervated extensor carpi radialis brevis (25.7%). CONCLUSIONS: The radial nerve exhibits significant variability in the posterior forearm. However, there is enough consistency to identify an archetypal pattern and order of innervation. These findings may also need to be considered when planning surgical approaches to the distal arm, elbow and proximal forearm to prevent an undue loss of motor function. The review of the literature yielded multiple studies employing inconsistent metrics and terminology to define order or innervation.

Unusual bilateral sensory innervation of the dorsum of hand by lateral antebrachial cutaneous nerve: a case report.

A 68-year-old male cadaver showed bilateral variation in the sensory innervation of the dorsum of hand. On the dorsum of right hand, first digit and lateral half of second digit were supplied by lateral antebrachial cutaneous nerve (LABCN); medial side of second digit and lateral side of third digit were supplied by superficial branch of radial nerve (SBRN) and medial side of third digit, the fourth and fifth digits were supplied by dorsal cutaneous branch of ulnar nerve (DBUN). On the dorsum of the left hand, lateral side of first digit was supplied by LABCN, medial side of first digit, the second and third digits as well as the lateral side of fourth digit were supplied by SBRN; medial side of fourth digit and fifth digit were supplied by DBUN. These variations would be helpful in understanding peripheral neuropathy, in interpretation of conduction velocity studies and in reconstructive surgery of hand.

Unusual bilateral sensory innervation of the dorsum of hand by lateral antebrachial cutaneous nerve: a case report / 대한해부학회지

A 68-year-old male cadaver showed bilateral variation in the sensory innervation of the dorsum of hand. On the dorsum of right hand, first digit and lateral half of second digit were supplied by lateral antebrachial cutaneous nerve (LABCN); medial side of second digit and lateral side of third digit were supplied by superficial branch of radial nerve (SBRN) and medial side of third digit, the fourth and fifth digits were supplied by dorsal cutaneous branch of ulnar nerve (DBUN). On the dorsum of the left hand, lateral side of first digit was supplied by LABCN, medial side of first digit, the second and third digits as well as the lateral side of fourth digit were supplied by SBRN; medial side of fourth digit and fifth digit were supplied by DBUN. These variations would be helpful in understanding peripheral neuropathy, in interpretation of conduction velocity studies and in reconstructive surgery of hand.

Anatomical Snuffbox and it Clinical Significance: A Literature Review / La Tabaquera Anatómica y su Importancia Clínica: Una Revisión de la Literatura

The anatomical snuffbox is a small triangular area situated in the radial part of the wrist, often used to perform clinical and surgical procedures. Despite the frequency with which this area is used, there is scarce information in literature about its details. The objective of this study is detailed knowledge of the anatomical snuffbox's anatomy and its components, the reported alterations at this portion, besides the clinical uses and significance of this area.

La tabaquera anatómica, es una pequeña área triangular ubicada en la parte radial de la muñeca utilizada a menudo para realizar procedimientos clínicos y quirúrgicos. A pesar de la frecuencia con la que se utiliza esta zona, escasea la información acerca de sus detalles en la literatura. El objetivo de este estudio es conocer con detalle la anatomía de la tabaquera anatómica y sus componentes, las alteraciones reportadas a ese nivel, y los usos e importancia clínica de esta región.

An anomalous pattern of superficial branch of radial nerve - a cadaveric case report / Patrón anómalo del ramo superficial del nervio radial - reporte de caso en un cadaver

In the present case study, there is an anomalous pattern of superficial branch of radial nerve (SBRN) that can be recognized as an anatomical variant of the left upper limb of a 60 years old donated embalmed male cadaver in the Department of Human Anatomy, Universiti Putra Malaysia, in which the superficial branch of radial nerve supplies the extensor carpi radialis longus and extensor carpi radialis brevis muscle. The superficial branch of radial nerve gave off branch to supply the proximal fusion part of extensor carpi radialis longus and extensor carpi radialis brevis muscles immediately after bifurcation of the radial nerve into the superficial branch of radial nerve and deep branch of radial nerve. This variation is very important to the surgeon as the presence of the variant will make them more careful in dealing with nerve entrapment surgery, reconstructive surgery and in the pain management services, the variation giving indications for treatment.

En el presente estudio se observó un caso de un patrón anómalo del ramo superficial del nervio radial (RSNR) reconocido como una variante anatómica del miembro superior izquierdo en un cadáver de sexo masculino de 60 años perteneciente al Departamento de Anatomía Humana de la Universidad Putra, Malasia. En este caso el ramo superficial del nervio radial inervaba a los músculos extensores radial largo y corto del carpo. El ramo superficial del nervio radial otorgaba un ramo a nivel del origen fusionado de los músculos extensores radiales del carpo, inmediatamente después de la división en ramos superficial y profundo del nervio radial. Esta variación es de importancia para el cirujano debido a que requiere un mayor cuidado en el tratamiento quirúrgico de atrapamiento del nervio o cirugía reconstructiva para el manejo del dolor.