Intramuscular Martin-Gruber anastomosis

The incidence and morphology of the intramuscular Martin-Gruber anastomosis are presented based on the study of 118 human cadavers (55 male, 63 female). The Martin-Gruber anastomosis was found in 25 (21.2%) of the 118 cadavers. It occurred in 11 (20%) of the 55 male cadavers (4 bilateral, 7 unilateral; 5 left and 2 right) and in 14 (22.2%) of the 63 female cadavers (2 bilateral, 12 unilateral; 8 left and 4 right). Therefore, the Martin-Gruber anastomosis was found in 31 (13.1%) of the 236 upper limbs. According to a recent classification (Rodríguez-Niedenführ et al., 2000), pattern I was found in 29 cases (93.5%), corresponding to Type A in 13 (41.9%), Type B in 3 (9.7%) and Type C in 13 (41.9%), whereas pattern II was found in 2 cases (6.5%), both being a duplication of Type IC. Intramuscular Martin-Gruber anastomosis was a single anastomosis that originated in all cases from the anterior interosseous nerve (pattern IC) and then passed through a muscle bundle of the flexor digitorum profundus and behind the ulnar artery to join the ulnar nerve as a single connecting branch. It did not send branches to the flexor digitorum profundus. This intramuscular course was observed in 3 of the 13 cases of Type C anastomosis (23.1%) or 3 cases out of 31 Martin-Gruber anastomoses (10%).     

The Muscular Branching Patterns of the Ulnar Nerve to the Flexor Carpi Ulnaris and Flexor Digitorum Profundus Muscles

The branching pattern of the ulnar nerve in the forearm is of great importance in anterior transposition of the ulnar nerve for decompression after neuropathy of cubital tunnel syndrom and malformations resulting from distal end fractures of the humerus. In this study, 37 formalin-fixed forearms were used to demonstrate the muscular branching patterns from the main ulnar nerve to the flexor carpi ulnaris muscle (FCU) and ulnar part of the flexor digitorum profundus muscle (FDP). Eight branching patterns were found and classified into four groups according to the number of the muscular branches leaving the main ulnar nerve. Two (Group I) and three (Group II) branches left the main ulnar nerve in 18 and 17 forearms respectively. The remaining two specimens had four (Group III) and five (Group IV) branches each. Usually one or two branches were associated with the innervation of the FCU. However, in 2 cases, three and in one, four branches to FCU were observed. The FDP received a single branch in all cases, except in four, all of which had two branches. In six forearms, a common trunk was observed arising from the ulnar nerve to supply the FCU and FDP. The distribution of the muscular branches to the revealed muscles was outlined in figures and the distance of the origin of these branches from the interepicondylar line was measured in millimeters. The first muscular branch leaving the main ulnar nerve was the FCU-branch in all specimens. The terminal muscular branch of the ulnar nerve to the forearm muscles arose at the proximal 1/3 of the forearm in all specimens. In 7 forearms, Martin-Gruber anastomosis in form of median to ulnar was observed.     

Relationship between the ulnar nerve and the branches of the radial nerve to the medial head of the triceps brachii muscle

One branch of the radial nerve to the medial head of the triceps brachii muscle (MHN) has been described as accompanying or joining the ulnar nerve. Mostly two MHN branches have been reported, with some reports of one; however, the topographical anatomy is not well documented. We dissected 52 upper limbs from adult cadavers and found one, two, and three MHN branches in 9.6%, 80.8%, and 9.6% of cases, respectively. The MHN accompanying the ulnar nerve was always the superior MHN. The relationship between the ulnar nerve and the MHN was classified into four types according to whether the MHN was enveloped along with the ulnar nerve in the connective tissue sheath and whether it was in contact with the ulnar nerve. It contacted the ulnar nerve in 75.0% of cases and accompanied it over a mean distance of 73.6 mm (range 36–116 mm). In all cases in which the connective tissue sheath enveloped the branch of the MHN and the ulnar nerve, removing the sheath confirmed that the MHN branch originated from the radial nerve. The detailed findings and anatomical measurements of the MHN in this study will help in identifying its branches during surgical procedures. Clin. Anat. 00:1–16, 2018. © 2018 Wiley Periodicals, Inc.     

Martin-Gruber communicating branch: anatomical and histological study

We dissected 72 upper limbs of fresh cadavers and found 17 cases with a Martin-Gruber communicating branch (23.6%). These were classified into 4 types: type I (n=5, 29.4%): communicating branch between the anterior interosseous and ulnar nn, type II (n=3, 17.6%): Communicating branch between the median and ulnar nn., type III (n=3, 17.6%): Communicating branch between the muscular branches to the flexor digitorum profundus m., type IV (n=6, 35.3%): combination of type I or II and type III. At histologic examination the number and size of the nerve bundles each communicating branch contained proved to be very different. In one case of type II only a single nerve bundle was found. We suggest that the different numbers of nerve bundles innervate different amounts of the intrinsic hand musculature. The communicating branch with a single nerve bundle probably innervated only the first dorsal interosseous muscle.     

Which is the function of a martin‐gruber connection?

Clinical and diagnostic variations may occur due to the variable presence of a connection between the median and ulnar nerves in the forearm (Martin‐Gruber anastomosis). This incidence has a wide range at 7%–40%. Most commonly, the connection between the nerves is considered to be composed of motor fibers; although, a sensory role has also been described. It is important to note that the number of axons, or the nature of the fibers in this connection, have not yet been elucidated. Fifty upper limbs were examined evaluating morphometric characteristics of the Martin Gruber connection, dissected out, sectioned, and immunohistochemically stained for choline acetyltransferase (ChAT) and analyzed with ImageJ^©. The connection was observed in 32% of all cases (16/50). The nerve connections were identified as those in Pattern 1 group (12%‐type 1b, 19%‐type 1a, and 69%‐type 1c) and contained motor (ChAT positive) fibers (40.42 ± 10.5% per connection) with three to four fascicles in each. No statistically significant differences were found according to sex, side, or laterality. There were statistically significant differences in the percentages of ChAT positive fibers; however, this was dependent on the distribution being greater in those not distributed zonally. The presence of this connection is prevalent in almost a third of the cadavers dissected; the understanding of this complex composition in sensory and motor fibers allows for the optimization of diagnosis and treatment of certain median‐ulnar nerve injuries. Clin. Anat. 32:501–508, 2019. © 2019 Wiley Periodicals, Inc.     

The gross anatomy of the extrathoracic course of the intercostobrachial nerve

Recent reports emphasize the importance of preserving the intercostobrachial nerve (ICBN) during surgical procedures (i.e., mastectomy, axillary clearance). However, a limited number of scientific reports explore the surgical anatomy of this nerve. We dissected 100 adult human formalin-fixed cadavers (200 axillae). In all the cadavers the ICBN was present with variant contributions from intercostal nerves T1, T2, T3, and T4. The arrangements of the ICBN were typed as I through VIII. The components of Type I (45% or 90 of our specimens) included a branch to the posterior antebrachial cutaneous nerve, a branch to the anterior and lateral parts of the axilla, a branch to the medial side of the arm, and a branch to the medial antebrachial cutaneous nerve. Type II (25%) describes the ICBN arising from T2 and giving off a branch to the brachial plexus. In Type III (10%), lateral cutaneous branches of T2 and T3 fuse as a common trunk and then split immediately after exiting the intercostal space to form an ICBN. In type IV (5%), T2 and T3 join distally to form an ICBN that ends as its terminal branches. Type V (5%): T3 joins T2 from the same intercostal space proximally, with Type VI (3%) showing a very proximal branching of the sensory terminal nerves. Type VII (5%) displayed a contribution from T3 and a branch to the brachial plexus with multiple terminating branches. A contribution from T3 and T4 and a branch to the brachial plexus with multiple branches of termination comprised Type VIII (2%).     

Innervation of the medial epicondylar muscles: an anatomic study in 50 cases

The median nerve is classically distributed to the medial epicondylar muscles by two branches (superior and inferior) for the pronator teres muscle, a common trunk for the flexor carpi radialis and palmaris longus muscles, and a branch for the flexor digitorum superficialis muscle. The 50 dissections were made by two workers on 30 upper limbs of formolized cadavers and 20 limbs from fresh-frozen cadavers. The innervation of the pronator teres m. was classical in only 26% of cases, and the “normal” pattern for the flexor carpi radialis and palmaris longus mm. was found in only 40% of cases. The innervation of the flexor digitorum superficialis m. was the least subject to variations, a single branch being observed in 68% of cases. We found a solitary medio-ulnar anastomosis of Martin-Gruber to the flexor carpi ulnaris muscle. This study confirmed the great variability of the branches of the median nerve at the elbow, and the importance of identifying them in surgical procedures for transposition of the medial epicondyle.     

前臂近中段Thompson入路中桡神经深支医源性损伤的解剖学因素及对策

目的　探讨前臂近中段Thompson入路中容易发生桡神经深支损伤的解剖学因素并提出对策。 方法　教学用成人尸体标本48具,按照Thompson入路显露,观察前臂伸肌与桡神经深支及其肌支的位置关系;测量桡神经深支穿出旋后肌的位置距离桡侧腕短伸肌的横向距离;观察指伸肌和桡侧腕短伸肌在前臂近段的愈着情况,测量二者在肱桡关节线以远的愈着长度。 结果　指伸肌和桡侧腕短伸肌在前臂近段相愈着,愈着长度在肱桡关节以远(7.1±2.1)cm;桡神经深支在旋后肌下缘的穿出点与桡侧腕短伸肌尺侧缘的水平距离为(1.3±0.3) cm,与肱桡关节线距离为(6.1±1.8) cm。 结论　前臂近中段Thompson入路中容易发生桡神经深支损伤存在着解剖学因素,了解桡神经深支的解剖特点及其与前臂伸肌的位置关系可以避免桡神经深支损伤。     

Superficial palmar communications between the ulnar and median nerves in Turkish cadavers

The superficial palmar communicating branch between the ulnar and median nerves, the ramus communicans (RC), has been investigated by anatomical dissections in 30 hands of 15 cadavers in the Turkish population. A communicating branch between the ulnar and median nerves was found in 18 hands (60%). It was classified into 4 types: Type 1-RC emerging from the ulnar 4th common digital nerve (CDN) and uniting with the median 3rd CDN, Type 2-RC emerging from the median 3rd CDN and uniting with the ulnar 4th CDN, Type 3-RC extending horizontally between the 3rd and 4th CDN, Type 4-a plexiform RC formed by multiple twigs. Twelve hands (40%) showed the Type 1 arrangement, one was Type 2 (3.3%), two were Type 3 (6.7%) and three (10%) were Type 4, based on the classification devised by Meals and Shaner ([1983] J Hand Surg Am 8:411-414) and modified by Bas and Kleinert ([1999] J Hand Surg Am 24:1171-1184). Knowledge of the anatomical characteristics of this branch is important for surgical interventions, especially in carpal tunnel release operations.     

内窥镜下微创治疗肘管综合征的相关解剖学研究

目的　为内窥镜下进行肘管尺神经减压并前移术提供临床应用解剖基础。 方法　10例新鲜尸体标本、20例临床病例传统手术中尺神经在臂部、前臂游离长度,尺神经第1肌支距离肱骨内上髁的距离、尺神经前移距离。在4例新鲜尸体标本上模拟手术。 结果　此术式尺神经前臂、臂部游离距离为（3.90±0.145）cm（3.64~4.23 cm）、（4.21±0.18）cm（3.80~4.53 cm）,前移距离（1.49±0.05）cm（1.39~1.57 cm）,尺神经第1肌支距离肱骨内上髁距离（2.18±0.38）cm（1.13~2.72cm）。此术式入路点、轴线、层面：肱骨内上髁与尺骨鹰嘴间长约2 cm纵行切口;肱骨内上髁与尺骨鹰嘴之间中点与豌豆骨连线上约7cm长的轴线,肱骨内上髁与尺骨鹰嘴之间中点与肱二头肌内侧肌间隔中点连线上长8cm的轴线;奥本斯韧带、前臂尺侧腕屈肌之间纤维弓形组织表面,臂部深筋膜表面。模拟手术成功。 结论　研究证实此术式可行,达预期效果。     

Accessory head of flexor pollicis longus muscle in fetuses and adult cadavers and its relation to anterior interosseous nerve

This study was conducted to examine the accessory head of flexor pollicis longus muscle (ahFPL) and its relation with the anterior interosseous nerve (AIN) in human fetuses and adult cadavers. Ninety fetus forearms and 52 adult cadaver forearms were dissected to evaluate the incidence, morphology, and innervation of the ahFPL. The ahFPL was observed in 29/90 (32%) of the fetus forearms and 20/52 (39%) of the adult cadaver forearms. The overall side incidence was 34.5% (49/142) among total forearms examined. On the other hand, the population incidence of ahFPL was 42% (19/45) in fetuses while it was 50% (12/24) in adult cadavers. So, the overall incidence in humans was 44.9% (31/69) in the population studied. Compression of the AIN in the forearm by the ahFPL is known as one of the causes of the anterior interosseous nerve syndrome (AINS). So, the relation of ahFPL with the AIN was evaluated, and in light of previous classifications a modified new classification is proposed. The most common relation detected in this study was Type IVa (71.4%) (AIN and its branches coursed posterior to the ahFPL). While Type I was not observed in this study, the incidences of Type II, Type III, and Type IVb (all AIN branches 'without AIN itself' coursed posterior to the ahFPL) were 2%, 14.3%, and 12.3%, respectively. The Types I, IVa, and IVb are thought to be associated with complete or incomplete types of AINS and Type III with incomplete type of AINS only.     

带尺侧上副动脉尺神经转位的解剖及临床意义

目的为临床上带血管蒂的尺神经移植在健侧颈7移位治疗臂丛根性撕脱伤中的应用提供解剖学依据。方法取新鲜经动脉灌注红色乳胶的成人上肢标本22侧进行显微解剖,观察尺神经外部营养动脉的来源。另取患骨肿瘤而截肢新鲜成人上肢6侧作仅保留尺侧上副动脉的尺神经游离,采用动脉灌注墨汁和尺神经组织切片的方法,观察尺侧上副动脉对尺神经内部血供营养的范围。结果尺神经在腋部由胸外侧或腋动脉的分支供应,在内侧肌间隔后方由尺侧上副动脉供应,在尺神经沟由尺侧上副动脉与尺侧返动脉后支的吻合支供应,在前臂由尺侧返动脉和尺动脉的分支供应。尺侧上副动脉灌注墨汁后,尺神经腕部、手背支及腋部的神经束内微血管被墨汁充填。结论以尺侧上副动脉的起始处为血管蒂部旋转点,尺神经可提供平均为(46.5±2.6)cm的有血供的移植长度,可经胸前皮下隧道逆向转位与对侧颈7神经根吻合。以尺侧上副动脉为血供的尺神经移植的设计是合理的。     

Ulnar nerve innervation of the medial head of the triceps brachii muscle: A cadaveric study

Although the ulnar nerve is closely associated with the triceps brachii muscle, the literature does not normally describe it as supplying this muscle. However, recent research has examined the ulnar nerve in the upper arm and identified branches supplying the medial head of the triceps brachii muscle. This study aims to expand upon this research by describing the course and incidence of these branches in a larger sample size. We examined 50 specimens in 25 cadavers. Ulnar innervation of the medial head of the triceps brachii was identified in 14 specimens (28%). The mean distance of the ulnar nerve branch midpoint was 26% along a line between the surgical neck and an epicondyle line, with a range of 11–39%. Innervation of the triceps brachii muscle by the ulnar nerve has important clinical and surgical implications. Clin. Anat. 26:1028–1030, 2013. © 2013 Wiley Periodicals, Inc.     

Sural-tibial nerve communications in humans

We investigated the occurrence of a communication between the sural and tibial nerves in 49 legs of 28 Japanese cadavers. In front of the calcanean tendon, we found the communication in 7 legs (14.3%) or in 5 cadavers (18.9%). The sural nerve gave rise to a number of medial and lateral branches, including the lateral calcanean branch at the lateral side of the ankle. The communicating branch with the tibial nerve arose from the first medial branch and pierced the deep fascia of the leg. In 4 cases, the U-shaped communication was formed between the sural and tibial nerves, and in 3 cases, the Y-shaped communication. Electrophysiologi-cal evidence of an anomalous motor function of the sural nerve has been reported recently. We consider that the U-shaped communication between the sural and tibial nerves gives a morphological basis to the motor function of the sural nerve.     

Motor branching patterns of the ulnar nerve in the forearms of fetal cadavers

Purpose

The aim of this study was to investigate the branches of the ulnar nerve given to forearm muscles [flexor carpi ulnaris (FCU) and flexor digitorum profundus (FDP)] and typing of ulnar nerve according to distribution of these branches to the muscles.

Methods

From the collection of Anatomy Department Laboratory, Faculty of Medicine, Suleyman Demirel University, 116 upper limbs of fetuses showing no external anomaly and aging between 12th and 40th weeks of pregnancy, were included in this study for anatomical dissection. Parameters about the branching of fetal ulnar nerve were set as follows: branch/branches to FCU muscle and branch/branches to FDP muscle.

Results

Ulnar nerve was typed according to number, sequence, and distribution of motor branches of ulnar nerve. As a result of this typing, eight type branching model of ulnar nerve was confirmed.

Conclusions

Our study is critically important for implementing successful surgical interventions and minimizing complications especially in ulnar nerve and forearm muscles surgery also in nerve replacement on this area.     

Median artery revisited

This study confirms that the median artery may persist in adult life in 2 different patterns, palmar and antebrachial, based on their vascular territory. The palmar type, which represents the embryonic pattern, is large, long and reaches the palm. The antebrachial type, which represents a partial regression of the embryonic artery is slender, short, and terminates before reaching the wrist. These 2 arterial patterns appear with a different incidence. The palmar pattern was studied in the whole sample (120 cadavers) and had an incidence of 20%, being more frequent in females than in males (1.31), occurring unilaterally more often than bilaterally (41) and slightly more frequently on the right than on the left (1.11). The antebrachial pattern was studied in only 79 cadavers and had an incidence of 76%, being more frequent in females than in males (1.61); it was commoner unilaterally than bilaterally (1.51) and was again slightly more prevalent on the right than on the left (1.21). The origin of the median artery was variable in both patterns. The palmar type most frequently arose from the caudal angle between the ulnar artery and its common interosseous trunk (59%). The antebrachial pattern most frequently originated from the anterior interosseous artery (55%). Other origins, for both patterns, were from the ulnar artery or from the common interosseous trunk. The median artery in the antebrachial pattern terminated in the upper third (74%) or in the distal third of the forearm (26%). However, the palmar pattern ended as the 1st, 2nd or 1st and 2nd common digital arteries (65%) or joined the superficial palmar arch (35%). The median artery passed either anterior (67%) or posterior (25%) to the anterior interosseous nerve. It pierced the median nerve in the upper third of the forearm in 41% of cases with the palmar pattern and in none of the antebrachial cases. In 1 case the artery pierced both the anterior interosseous and median nerves.     

Lateromedial and dorsoplantar borders among supplying areas of the nerves innervating the intrinsic muscles of the foot

The branching patterns of nerves supplying the intrinsic muscles of the foot were analyzed as a basis to confirm the muscle layer structure. Thirty‐eight feet of 20 Japanese cadavers were examined in detail in this study. The first dorsal interosseus was innervated by a branch from the deep peroneal nerve as well as a branch of the lateral plantar nerve in 92.1%, the second dorsal interosseus in 10.5% and the third dorsal interosseus in 2.6%. In three specimens, branches from the deep peroneal nerve innervated the oblique head of the adductor hallucis or the lateral head the flexor hallucis brevis. In addition, branches from the medial and lateral plantar nerves and the deep peroneal nerve formed communication loops in three specimens. The first dorsal interosseus, the oblique head of the adductor hallucis and the lateral head of the flexor hallucis and their innervating nerve branches are closely related within the first intermetatarsal space. Since the tibial part of the first interosseus muscle primordium is occupied in the space during development, the variations of innervation patterns and formation of the communicating nerve loops may be explained by various combinations of the part and the other muscle primordia. Anat Rec 255:465–470, 1999. © 1999 Wiley‐Liss, Inc.     

Report of a rare human variation: absence of the radial artery

A case of unilateral absence of the radial artery is reported. The arterial system of the specimen was developmentally primitive with the anterior interosseous artery the chief blood supply to the forearm and hand. A "superficial ulnar artery" of small caliber supplemented the supply of the hand. Three large branches of the anterior interosseous artery supplied the hand with the lateral terminal branch replacing the radial artery distal to the wrist. The superficial palmar arch was formed by an anastomosis of the media and lateral terminal branches of the anterior interosseous artery. No deep palmar arch was present, but three palmar metacarpal arteries arose from a perforating artery which branched from a large dorsal branch of the anterior interosseous artery. The median artery was of small caliber and could not be traced beyond the midforearm. Based on this specimen and a review of other forearm and hand arterial variations, it is postulated that the ulnar artery may developmentally precede the median artery.     

前臂骨间膜前面尺侧的动脉及其与穴位的关系

目的：探讨前臂骨间膜前面尺侧的动脉分布及其与心经穴位的关系。方法：成人前臂动脉乳胶灌注及墨汁灌注的标本,解剖观测其骨间膜前面尺侧的动脉分布。结果：前臂骨间膜前面尺侧的动脉来自骨间前动脉及其前终末支的节段性分支,在心经沿线2、3寸处的动脉支出现率均大于59．3％,2寸处动脉支管径粗、分支多、供血量大,且向下密集分布到与心经穴位相关的骨间膜远段。结论：前臂骨间膜前面尺侧的动脉呈节段性分支分布,与心经相关穴位的血管分布较密集。