Anomalous flexor digiti minimi brevis in Guyon's canal

In an adult male cadaver, the flexor digiti minimi brevis, a muscle of the hypothenar eminence, was found to arise from the superficial transverse septum (between the superficially placed flexor carpi ulnaris, palmaris longus, and flexor carpi radialis muscles, and the deeply placed flexor digitorum superficialis muscle) in the distal fourth of the flexor aspect of the left forearm. The muscle exhibited two strata of muscle fibers at its origin. The superficial stratum was a thin layer of transversely running fibers confined to the forearm, which has not been previously reported. The deep stratum, a thick layer of longitudinally running fibers, formed the bulk of the muscle. It traversed Guyon's canal superficial to the ulnar nerve and vessels to reach the hypothenar eminence. Its course through Guyon's canal could be a cause for ulnar tunnel syndrome. The ulnar nerve trunk innervated not only the anomalous flexor digiti minimi brevis muscle, but also abductor digiti minimi and palmaris brevis. This may be due to the common phylogeny of these three muscles from the same muscle mass.     

腕部尺神经卡压的解剖学研究及其临床意义

目的：为腕部尺神经卡压的诊断和治疗提供解剖学依据。方法：对20例新鲜成人上肢标本的腕部进行解剖，观测尺神经行径中可能存在的卡压因素。结果：尺神经在腕尺管内分成浅、深两支，浅支于小鱼际肌腱弓浅面出腕尺管；深支在小鱼际肌腱弓深面穿出腕尺管后，走行于小指对掌肌浅、深两头腱性起点和钩骨钩之间的间隙，小指对掌肌浅头腱性起点近侧缘锐利成腱弓样，存在率100％。腕尺管内尺神经和尺动脉之间存在3种交叉伴行关系：尺动脉发出的小鱼际肌营养血管和尺神经深支交叉占10％，尺动脉深支和尺神经浅支交叉占20％，尺动脉深支和尺神经深、浅支分别交叉占70％。结论：尺神经在腕部的行程分为腕尺管段和小鱼际肌段，小指对掌肌腱弓可以卡压尺神经深支，尺动脉和尺神经之间的多种交叉伴行关系是尺动脉卡压尺神经的基础。     

Common variations in muscles and tendons of the human hand

Common variations in muscles and tendons of the hand were determined by dissecting 40 pairs of hands (20 male, 20 female). Contrary to some anatomy textbooks which describe only three palmar interossei, with the thumb lacking one, this study found four palmar interossei present in 85% of hands and 90% of bodies. This first palmar interosseous typically arose from the base of the first metacarpal and inserted along with the tendon of the oblique head of adductor pollicis into the base of the proximal phalanx. Forty hands (50%) did not have the usual arrangement of lumbricals. Twenty-seven (34%) third lumbricals and four (5%) fourth lumbricals split at their insertions; four third lumbricals and four fourth lumbricals inserted on the ulnar side of the middle and ring fingers, respectively. The abductor pollicis longus inserted by 2 or 3 tendons in 91% of hands. The tendon of extensor digiti minimi split into 2 or 3 slips in practically all of the hands studied (96%). The tendon of extensor indicis split into 2 slips in more than a third (38%) of hands. In almost a third (30%) of hands there were accessory extensor muscles present deep to the tendons of extensor digitorum. Lastly, extra slips of origin of the abductor digiti minimi were present in 10% of hands. This study confirms the presence of a palmar interosseous muscle for the thumb and demonstrates that some variations occur more frequently than was expected. © 1993 Wiley-Liss, Inc.     

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。     

The anatomical variations of the extensor tendons to the dorsum of the hand

To lead a quality life, tendon repair must be performed in a trauma causing damage to the extensor tendon of the hand. The aim of this study is to study the structures that can be used as donor tendons. Fifty-four dissected adult hands were examined to study the pattern of the extensor tendons on the dorsum of the hand. The most common distribution patterns of the extensor tendons of the fingers were as follows: a single extensor indicis proprius (EIP) tendon which inserted ulnar to the extensor digitorum (ED)-index; a single ED-index; a single ED-middle; a single ED-ring; an absent ED-little; a double extensor digiti minimi (EDM), and a single ED-ring to the little finger. The frequency of the number of tendons is as follows: a single (87.03%) EIP, a single ED-index (100%), a single (92.6%) ED-middle, a single (75.9%) ED-ring, and an absent (68.5%) or a single (24.1%) ED-little. A double (88.9%) EDM tendons were seen. The thickest type of juncturae tendinum (JT) is found primarily between the ring and little fingers (90%). Suitable excessive tendon and the thickest JT as donor tendon were found in the fourth intermetacarpal space. The present findings, especially the fourth intermetacarpal space, may explain why incisions on the dorsum of the hand should be large and performed with particular care. It is necessary to have a thorough understanding of the arrangements of the multiple extensor muscles and their junctural connections of the hand when tenoplasty or tendon transfer is required.     

小指对掌肌腱弓的解剖学研究

目的探讨Guyon管以远尺神经深支卡压征的解剖学基础。方法对20例新鲜成人上肢标本腕部进行显微解剖，肉眼及镜下观测腕部尺神经分支与周围组织的关系。结果尺神经穿出Guyon管后进入小指对掌肌浅、深两头和钩骨钩之间的间隙，该间隙可分为顶、底和桡侧壁，有一个入口和一个出口，暂称其为小指对掌肌间隙。小指对掌肌浅头腱性起点的近侧缘锐利，呈腱弓样，存在率100％，暂称其为小指对掌肌腱弓。结论小指对掌肌腱弓可以卡压尺神经深支，引起除小鱼际肌以外的尺神经支配的所有手内在肌的功能障碍。     

肘部尺神经及其血供的应用解剖学研究

目的 观察肘部尺神经及其血供,为临床带血供尺神经前移术治疗肘管综合征提供解剖学依据。 方法　①动脉灌注红色乳胶并防腐固定的30侧成人上肢标本,观测肘管段尺神经及其血供情况;游离1侧肘部尺神经及其供血动脉,观察神经与供血动脉的位置关系。②动脉灌注明胶-氧化铅悬液的成人新鲜标本6侧,游离尺神经及其营养血管,行X线摄片,观察尺神经营养血管的吻合情况。③动脉灌注红色乳胶并防腐固定的30侧成人上肢标本上模拟临床尺神经前移术,测量带血供尺神经无张力前移距离。 结果　肘部尺神经血供来自尺侧上副动脉（SUCA）、尺侧下副动脉（IUCA）和尺侧返动脉背侧支（PURA）,3条营养血管与尺神经平均伴行长度分别是15.7、5.0和5.9 cm;至肱骨内上髁距离分别是15.0、4.5和5.0 cm;带血供尺神经无张力性平均前移距离为1.8 cm。尺神经在肘部发出1~2支关节支,2~3支肌支。 结论　带血供尺神经前移术治疗肘管综合征切实可行,能很好的保护尺神经及其血供。     

小趾展肌神经与神经源性跟痛症关系的解剖学基础

目的　探讨小趾展肌神经的局部解剖特点及其与神经源性跟痛症的关系,为临床诊断治疗提供解剖学依据。 方法　32侧防腐成人尸体下肢标本,解剖观察小趾展肌神经的起源、分支、走行和分布特点。 结果　小趾展肌神经81.25%起源于足底外侧神经,起点59.38%位于后上象限;起点与参考线的垂直深度,左侧（10.81±0.96）mm,右侧（10.24±1.10）mm;小趾展肌神经发出1～3支骨膜支到达跟骨结节内侧突的骨膜;小趾展肌神经与跟骨结节内侧突该的水平距离左侧（19.95±1.82）mm,右侧（20.89±2.48）　mm 。 结论　小趾展肌神经行经　展肌和足底方肌内侧头之间,跟骨结节内侧突前可能被卡压,卡压或病变（特别是骨膜支）可能与足底腱膜炎发生有关;跟骨骨刺不一定会造成神经源性跟痛症。     

The course and branching pattern of pudendal nerve in fetus

The pudendal nerve is a considerably large branch of the sacral plexus. There are many articles in the literature concerning the pudendal nerve in adults, but as far as we know, there is none on the branching pattern and variations in pudendal nerve anatomy in fetus. This study investigates the pudendal nerve trunking with respect to the piriformis muscle in 25 formalin-fixed fetuses (50 sides of pelves, 15 females, 10 males), ranging from 20 to 37 weeks of gestation. We investigate pudendal nerve trunking in four types: Type I-a is defined as single-trunk with the inferior rectal nerve branching proximal to the dorsal nerve of penis/clitoris (38%), Type I-b is also single-trunk with the dorsal nerve of penis/clitoris branching proximal to the inferior rectal nerve (24%), Type II is double-trunk with medial trunk as an inferior rectal nerve (34%), and Type III is triple-trunk (4%). We measured the average diameter of the main trunk of pudendal nerve in Type I-a and I-b groups to be 0.98 +/- 0.33 mm. We also measured the average length of the pudendal nerve trunks before the dorsal nerve of penis/clitoris branch to be 7.35 +/- 3.50 mm. There was no significant statistical difference in the average length, diameter, number of trunks, and pudendal nerve variations between male and female and also right and left sides of the pelves. This first and detailed fetal study of pudendal nerve trunking with respect to the piriformis muscle would be useful for educational anatomy dissections and anatomical landmark definitions for relevant clinical procedures.     

尺神经深支的形态特点及其临床意义

目的：为临床尺管综合征和尺神经深支损伤的诊治提供解剖学基础。方法：在３０只成人手标本上解剖观测了尺神经深支的走行、毗邻关系、终末分支和分布。结果：依据尺神经深支的走行可分为：豆钩管段、小鱼际肌段、掌中段和终末段。小鱼际肌段行于小指对掌肌与第５掌骨之间的占５６．７％；在小指对掌肌间隙的走行占３０％；在小指短屈肌与小指对掌肌之间占１３．３％。终末段分支为４支型的占８６．７％，３支型占１３．３％。结论：尺神经深支的豆钩管段与豌豆骨、钩状骨钩关系密切；小鱼际肌段与第５掌骨基底紧邻。豌豆骨、钩骨钩和第５掌骨基底部骨折，极易损伤此神经。     

An aberrant anatomic variation along the course of the ulnar nerve above the elbow with coexistent cubital tunnel syndrome

We report on a patient with an unusual anatomic variation along the course of ulnar nerve above the elbow who had cubital tunnel syndrome. The variation consisted of a cutaneous neural branch that was originating at a distance of approximately 40 mm proximal to the medial epicondyle, and from the radial aspect of the main trunk of ulnar nerve. The branch had a superficial course and it was passing distally, anterior to the medial epicondyle without penetrating the fascia of the flexor muscles origin. Anterior intramuscular transposition of the ulnar nerve was performed leaving the newly found branch over the fascia between the muscles and the adipose subcutaneous tissue.     

尺神经、肘管的解剖学观察及临床意义

目的解剖学观察测量成人尺神经、肘管的形态结构,为临床手术治疗肘管综合症提供解剖学基础。方法采用解剖学方法对成人尸体26具(男16具,女10具)解剖观察测量肘管后壁长度,切开肘管后壁,将尺神经前移,测量其前移的最大距离。结果肘管后壁长度:男性为(2.38±0.43)cm,女性为(2.15±0.38)cm;切开肘管后壁将尺神经前移至肱骨内上髁前方皮下,最大前移的距离:男性为(1.53±0.31)cm,女性为(1.38±0.41)cm。结论临床手术治疗肘管综合症,切开肘管后壁进行时,可切开长度在2.15~2.38 cm,肘管内尺神经前移距离在1.38~1.53 cm之间,不会产生术后神经张力增加。     

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。     

Anatomical basis for a technique of ulnar nerve transposition

Summary There are five major anatomical locations where the ulnar nerve may be compressed near the elbow. Multiple sites of compression are often noted clinically; in other cases, the site of compression is difficult to identify. Clinical experience and results of a series of 20 anatomical dissections suggest that local decompression or subcutaneous transfer may be performed without necessarily exposing all five locations, posing a risk of incomplete decompression. Submuscular transfer of the ulnar nerve decompresses all five locations simultaneously and thus theoretically may be more reliable. The potentially superior results predicted by this anatomical investigation have been confirmed in a clinical case review. Submuscular transposition of the ulnar nerve is reliable and safe, not only in the primary treatment of ulnar neuropathy at the elbow but also in revision of previous operations. Presented at the Second Annual Meeting of the American Association of Clinical Anatomists, Omaha, June 7 to 8, 1985     

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.     

Anatomical variations of the sural nerve

An anatomical study of the formation of the sural nerve (SN) was carried out on 76 Thai cadavers. The results revealed that 67.1% of the SNs were formed by the union of the medial sural cutaneous nerve (MSCN) and the lateral sural cutaneous nerve (LSCN); the MSCN and LSCN are branches of the tibial and the common fibular (peroneal) nerves, respectively. The site of union was variable: 5.9% in the popliteal fossa, 1.9% in the middle third of the leg, 66.7% in the lower third of the leg, and 25.5% at or just below the ankle. One SN (0.7%) was formed by the union of the MSCN and a different branch of the common fibular nerve, running parallel and medial to but not connecting with the LSCN, which joined the MSCN in the lower third of the leg. The remaining 32.2% of the SNs were a direct continuation of the MSCN. The SNs ranged from 6-30 cm (mean = 14.41 cm) in length with a range in diameter of 3.5-3.8 mm (mean = 3.61 mm), and were easily located 1-1.5 cm posterior to the posterior border of the lateral malleolus. The LSCNs were 15-32 cm long (mean = 22.48 cm) with a diameter between 2.7-3.4 mm (mean = 3.22 mm); the MSCNs were 17-31 cm long (mean = 20.42 cm) with a diameter between 2.3-2.5 mm (mean = 2.41 mm). Clinically, the SN is widely used for both diagnostic (biopsy and nerve conduction velocity studies) and therapeutic purposes (nerve grafting) and the LSCN is used for a sensate free flap; thus, a detailed knowledge of the anatomy of the SN and its contributing nerves are important in carrying out these and other procedures.     

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.     

Ulnar nerve cutaneous distribution in the palm: Application to surgery of the hand

The ulnar nerve (UN) was classically described as supplying most of the intrinsic muscles of the hand, and the cutaneous innervation of the ulnar one and half digits, by dividing into superficial sensory and deep motor branches in Guyon's canal. Variations of this pattern have been reported in the literature. This study investigated the cutaneous distribution of the UN in the palm following the dissection of 144 cadaveric hands. The UN was examined and the distances from branching points of the superficial branch to the proximal edge of the pisiform were measured. The UN bifurcated (80.4%) into one deep trunk and one superficial trunk, which further divided distally into the proper digital (PDN) and common digital (CDN) nerves or trifurcated (19.6%) into one deep trunk, a PDN and a CDN in Guyon's canal. It received fibers from the median nerve in four cases and from the dorsal branch of the UN in six cases. A classification scheme based on the nerves contributing to the sensory innervation of the ulnar side of the palm was suggested. Understanding the cutaneous distribution of the UN in the palm and appreciating possible communicating branches can help clinicians to assess hand pathologies better and avoid injuries during surgical interventions. Clin. Anat. 28:1022–1028, 2015. © 2015 Wiley Periodicals, Inc.     

肘管尺神经内压测量及其临床意义

目的 为探讨尺神经卡压症的发病机制,寻找本病的最佳治疗手段,提供基础资料。方法 利用神经内探针测量成人肘管的尺神经内部压力。结果 肘管内尺神经内部压力与肘后三角韧带的形态及关节活动状态有关。尺神经内压屈肘时升高(1.89kpa),伸肘时降低(0.93kpa);切断肘后三角韧带后尺神经内压明显降低,届肘时0.88Kpa,伸肘时0.61kpa。结论 手术治疗尺神经卡压症时,宜采取切断肘后三角韧带,将尺神经前置,充分降低尺神经内部压力,解除尺神经卡压症状。     

尺神经及其血供在肘管综合征手术中应用解剖研穷

目的观察肘部尺神经及其血供,为尺神经前移术治疗肘管综合征提供解剖学基础。方法50侧成人上肢标本观察测量肘部尺神经及其血供情况。结果肘部尺神经血供有3个来源:尺侧上副动脉(IUCA)、尺侧下副动脉(IUCA)和尺侧返动脉后支(PURA),分别与尺神经伴行长度为(15.1±2.0)cm、(5.0±1.1)cm和(6.4±1.2)cm;尺神经在肘部发出1～2支关节支,2～3支肌支。结论行尺神经前移术治疗肘管综合征时保护尺神经及其血供是完全可能的。