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%).     

An anatomic study on the Martin-Gruber anastomosis

Summary The incidence of Martin-Gruber anastomosis was studied. Anatomical dissection of 108 cadaveric arms was performed. The Martin-Gruber anastomosis was found in 23 arms. This anastomosis was classified into four types: Type Ia: Communication between the anterior interosseous and the ulnar nn. (n=13), Type Ib: Communication between the median and ulnar nn. (n=1), Type II: Communication between muscular branches of the flexor digitorum profundus m. (n=8), Type III: Combination of Type Ia or Ib and Type II (n=1). The incidence of Martin-Gruber anastomosis was found to be significantly higher in the present study than in previous studies.

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Etude anatomique de l'anastomose de Martin-Gruber

Résumé La fréquence de l'anastomose de Martin-Gruber a été étudiée sur les dissections de 108 membres supérieurs de cadavres. L'anastomose a été trouvée 23 fois. Cette anastomose est classée en 4 types : type Ia : anastomose entre le nerf interosseux antérieur et le nerf ulnaire (n=13) ; type Ib : anastomose entre le nerf médian et le nerf ulnaire (n=1) ; type II : anastomose entre les rameaux musculaires du m. fléchisseur profond des doigts (n=8); type III : combinaison du type Ia ou Ib et du type II (n=1). La fréquence de l'anastomose de Martin-Gruber apparait plus élevée que dans les travaux précédents.

     

尺神经中第七颈神经成份的行径及临床意义

用神经束追踪分离法解剖观察100侧成人第七颈神经分布至尺神经内的纤维行径。结合临床观察认为,尺神经内部有来自颈七的纤维,主要经4个交通部位加入到尺神经分布区内。证明脊神经相应节段与骨骼肌或肌群的支配关系是恒定的,只是由于在胚胎发生上臂丛组合的不同,使脊神经的分支到所支配的骨骼肌间的行径出现差异。上述研究结果,对臂丛中、下干损伤准确定位诊断有重要意义。     

Stratification of the flexor retinaculum and the course and distribution of the ulnar, median, and palmar digital nerves: an anatomical study

A gross anatomic study of 169 hands from 94 human adult cadavers was carried out to define the morphology of the flexor retinaculum and the relationship of the flexor retinaculum to the course of the median and ulnar nerves and branching of the palmar digital nerves. The following results were obtained. Three parts of the flexor retinaculum were arranged like overlapping tiles on a roof, and in all cases, the median nerve passed deep to the flexor retinaculum, whereas the ulnar nerve passed through various parts of the flexor retinaculum in 19% of cases irrespective of its proximal form and branching of the palmar digital nerves.     

手掌分区与正中神经和尺神经

目的：为研究手掌病变、作神经吻合及阻滞麻醉提供解剖学基础。方法：手掌借5条横平行线和掌纵纹，分为桡、尺两部及6个区。解剖并观察正中神经和尺神经在手掌各区的分支及分布。结果：正中神经掌皮支和主支位于Ⅰ、Ⅱ区，主支在Ⅲ区形成4种形态的伞形结构，在C线处发出第1～3指掌侧总神经。正中神经返支由伞形结构桡侧发出，经B1点入大鱼际。尺神经主支和掌皮支位于Ⅰ区。浅支在A1点分为指掌侧总神经和小指掌侧固有神经，深支于A1点入手掌Ⅱ区深面。指掌侧总神经在E线分为指掌侧固有神经。结论：手掌神经有按区分布的特点，有助于手掌损伤离断神经的寻找和吻合，以及手掌神经阻滞麻醉的精确定位。     

Communications between the palmar digital branches of the median and ulnar nerves: A study in human fetuses and a review of the literature

In this study, median nerves (MNs) and ulnar nerves (UNs) were dissected in 200 palmar sides of hands (left and right) of 100 (50 male, 50 female) spontaneously aborted fetuses with no detectable malformations. The fetuses, whose gestational ages ranged from 13 to 40 weeks, were dissected under an operating microscope. The MN divided first into a lateral ramus and a medial ramus and then formed a common digital nerve. The first common digital nerve trifurcated in all of the studied cases. The branching patterns were classified into two types (Type 1 and Type 2) based on the relationship with the flexor retinaculum (behind/distal of it). A communication branch between the UNs and MNs in the palmar surface of the hand was found in 59 hands (29.5%). The proper palmar digital nerves were numbered from p1 to p10, starting from the radial half of the thumb to the ulnar half of the little finger, and these nerves exhibited six types of variations. The present data obtained from human fetuses will aid in elucidating the developmental anatomy of the nervous system and provide hand surgeons with a more complete anatomical picture to help them to avoid iatrogenic injuries. Clin. Anat. 23:234–241, 2010. © 2009 Wiley‐Liss, Inc.     

早期腕管综合征的电生理指标比较

目的:分析诊断早期腕管综合征的电生理指标,比较其敏感性。方法:对临床诊断为早期腕管综合征、正中神经远端运动电位潜伏期(distal motor latency,DML)<4.5ms的患者50例60侧,测定正中神经、尺神经环指-腕的感觉神经动作电位(SNAP)潜伏期差值,正中神经、桡神经拇指-腕的SNAP潜伏期差值,以及正中神经节段检查两点间潜伏期差值,并对其结果进行比较分析。结果:正中神经、尺神经环指-腕的SNAP潜伏期差值异常(≥0.4ms)者58侧,达96.6%;正中神经、桡神经拇指-腕的SNAP潜伏期差值异常(≥0.4ms)者40侧,达80%;正中神经节段检查两点间潜伏期差值异常(≥0.4ms)者25侧,达41.6%。结论:正中神经、尺神经环指-腕的SNAP潜伏期差值异常是早期腕管综合征最敏感的指标。     

Galen's "anastomosis" revisited

This study aimed to examine the incidence and contribution to the innervation of the larynx from Galen's "Anastomosis" (GA), which is the direct connection between the dorsal branches of the internal laryngeal nerve (ILN) and the recurrent laryngeal nerve (RLN). Fifty adult laryngeal specimens were micro-dissected. The diameter of the ILN and RLN were measured immediately after each had given off their muscular branches to form GA. The incidence of GA was 81%. The average diameter of the ILN after giving off muscular branches to form GA was 1.28 mm (right) and 1.27 mm (left) while the average diameter of the RLN after giving off muscular branches to form GA was 0.65 mm (right) and 0.68 mm (left). The weighted mean incidence of GA (77.3%) calculated from a review of the literature concurred with the present finding of 81%. The ILN and RLN supplied the laryngeal musculature. According to the results obtained; it appears that the ILN may provide a greater contribution to the connection between the ILN and RLN as the morphometric contribution from the ILN was larger in comparison to the RLN. In addition, the authors propose a suitable term viz. the "communicating branch" as opposed to the commonly used misnomer GA to describe the connection between the dorsal branch of the RLN and the ILN, based on the definition that an "Anastomosis" refers to blood vessels and that a single connection exists between the dorsal branch of the RLN and ILN.     

Microscopic anatomy of brachial plexus branches in Wistar rats

In the present study, we analyze the morphology and morphometry of the lateral proper digital nerve of the third finger, and of the proximal and distal segments of the ulnar, median, and radial nerves, in Wistar rats 4 or 7 weeks old. The fascicular area and diameter were generally significantly greater in the proximal compared to distal segments and tended to be larger in 7‐week‐old compared to 4‐week‐old rats (e.g., median nerve area of 0.13 mm² for the proximal and 0.07 mm² for distal segments in 4‐week‐old rats, and 0.17 and 0.10 mm², respectively, for the proximal and distal segments of 7‐week‐old rats). The number of fascicles was significantly greater while the number of myelinated fibers was significantly less in the distal segments (e.g., 1,359 and 509 myelinated fibers, respectively, in the proximal and distal segments of the radial nerve 4‐week‐old rats). There was no significant difference in these parameters between the two age groups. The diameter of the myelinated fibers and their respective axons increased from 4 to 7 weeks of age (e.g., myelinated fiber diameter of 4.10 μm in 4‐week‐old animals and 4.7 μm in the ulnar nerve proximal segment of 7‐week‐old rats). The g‐ratio regression line (axon diameter vs. fiber diameter quotient) was outlined for all the nerves studied here. Differences in myelinated fiber density were detected between the segments of the radial nerve, accompanying the number of myelinated fibers. Detailed knowledge of the microscopic anatomy of rat forelimb nerves provides control data for comparison with studies of experimentally induced neuropathies, which can shed more light on human neuropathies. Anat Rec, 290:477–485, 2007. © 2007 Wiley‐Liss, Inc.     

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.     

Deep palmar communications between the ulnar and median nerves

Innervation of the hand is supplied via the radial, median, and ulnar nerves. A common border of sensory distribution between the ulnar and median nerves is along the fourth digit. However, this sensory distribution may be affected by communication between these two nerves. Among the known communications between the median and ulnar nerves, the deep anastomotic branch in the hand is the least described and rarely illustrated in the literature. This study aims to provide data on the prevalence of a deep communicating branch via cadaveric dissection. We examined 50 hands taken from 25 adult cadavers. Communicating branches were found in 16% of the hands examined, with rami occurring bilaterally in two specimens. By describing the origin and pathway of this communicating branch, we hope to provide surgeons and clinicians with knowledge that may help avoid iatrogenic injuries.     

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.     

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.     

体神经-内脏神经吻合后异类神经再生过程的蛋白质组学分析

目的 使用蛋白质组研究技术研究大鼠体神经-内脏神经吻合术后异类神经再生过程中不同时段蛋白质表达的变化.方法 建立大鼠体神经-内脏神经吻合动物模型,分别于术后7d、14d、28d取出再生的异类神经与对侧正常的体神经,应用双向电泳技术对提取物进行分析,经图像分析系统识别差异蛋白质,用MALDI-TOF-MS对差异表达的蛋白质进行鉴定分析,获得的肽质指纹图谱进入数据库中检索.结果质谱分析识别了25种具不同功能的蛋白质,其中包括神经髓鞘中的成分、急性期炎性因子、神经细胞骨架蛋白和脂类代谢蛋白等.这些蛋白可能在Wallerian变性、轴突再生和再髓鞘化中起作用.结论获得了再生异类神经时序性双向电泳凝胶图谱,成功鉴定25个与异类神经再生相关的蛋白质,揭示了施万细胞和巨噬细胞在异类神经再生过程中所起的重要作用.     

Biometric study of the relationships between palmar neurovascular structures, the flexor retinaculum and the distal wrist crease

During surgical exposure of the carpal tunnel it is possible to injure the neurovascular structures closely related to the flexor retinaculum, such as the superficial palmar arch and the communicating branch between the ulnar and median nerves. Because of the importance of these structures and with the purpose of increasing knowledge of anatomical details concerning to their location, a biometric study was performed on the retinaculum and the communicating branch, and between the communicating branch and the distal wrist crease, as well as between the retinaculum and the superficial palmar arch. We dissected 56 hands from 28 Brazilian formalin‐preserved cadavers of both sexes (24 male) at the Federal University of São Paulo–Escola Paulista de Medicina, Brazil. The communicating branch was observed in 96.4% of cases and the superficial palmar arch in 78.6%. The communicating branch was found between the common palmar digital nerve of the 4th interosseous space (from the ulnar nerve) to the homonymous nerve of the 3rd interosseous space (from the median nerve). In males, the distance between the distal wrist crease and the site where the communicating branch originates from the ulnar component had an average of 33.9±5.5 mm on the right side and 30.2±8.2 mm on the left. The distance between the distal wrist crease and the junction of the communicating branch with the common palmar digital nerve of the 3rd interosseous space was 43.6±6.9 mm on the right and 40.2±6.2 mm on the left side. Conversely, in 14.8% of cases (1 female), the communicating branch was observed to emerge from the common palmar digital nerve of the 3rd interosseous space. The distance between the retinaculum and the superficial palmar arch in the axial line of the 4th metacarpal bone was on average 7.3±4.3 mm on the right and 8.3±3.5 mm on the left side. At the same level, the distance between the retinaculum and the communicating branch was 6.2±3.7 mm on the right side and 5.1±2.8 mm on the left. These results can be used as a reference during surgical procedures in the palmar region.     

Morphometric study of the cervical course of the hypoglossal nerve and its application to hypoglossal facial anastomosis

The hypoglossal nerve is used classically in salvage of facial paralyses in the absence of spontaneous recovery. A variety of ways of transferring and suturing the hypoglossal nerve to the distal segment of the facial nerve have been reported. In order to determine which mode of reconstruction is the best for neurotisation of the facial nerve, the caliber of the hypoglossal nerve was studied in ten subjects at the level of proximal and distal parts of the trunk and the cervical loop. The fascicular surface area of the cervical branch is inadequate for use. The distal extremity of the hypoglossal nerve has an ideal caliber to be sutured to the facial nerve trunk and the proximal part is large enough to allow partial harvesting of the hypoglossal nerve for neurotisation of the facial nerve.