Innervation of the supinator muscle and its relationship to two‐incision distal biceps tendon repair: An anatomic study

Reinsertion of the ruptured distal biceps tendon has been performed using either a single‐anterior incision or a two‐incision approach. A systematic review of these two repair methods has identified a higher incidence of supination weakness following the two‐incision approach. The objective of this study was to describe the innervation of the supinator muscle and its implications regarding a two‐incision distal biceps repair. Twelve fresh upper extremity specimens from 12 males were dissected with the forearm in full pronation. The number of branches of the posterior interosseous nerve (PIN) to the supinator, their site of exit from the PIN trunk, and their distance from a variety of known anatomic landmarks were recorded. Specimens were characterized as high (<5 mm), moderate (6–10 mm), or low (>10 mm) risk of nerve branch injury depending on the proximity of nerve branches to the bicipital tuberosity. In general, we found the innervation of the supinator to be highly variable. There were from two to nine branches of the PIN which supplied the supinator, with 0–3 arising from the ulnar side of the nerve. Four specimens were at low, five at moderate, and three at high risk of nerve branch injury during dorsal exposure of the bicipital tuberosity. We conclude that there is a substantial amount of variability in the innervation of the supinator, with certain patterns being at higher risk of nerve branch injury if dissection of the supinator is carried out over the bicipital tuberosity. Clin. Anat. 23:413–419, 2010. © 2010 Wiley‐Liss, Inc.     

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。     

The innervation of deep muscles of the human forearm extensors]

The innervation of four deep muscles of the human forearm extensors (the abductor pollicis longus, the extensor pollicis brevis, the extensor pollicis longus, and the extensor indicis muscles) were investigated in 24 bodies (48 sides) from those used in the 1989 and 1990 student courses in gross anatomy dissection at the Iwate Medical University School of Medicine. The forearm extensor muscles and the deep branch of the radial nerve were dissected intensively in the student courses in gross anatomy and were removed afterwards. The four deep muscles of the human forearm extensors and the nerves innervating the muscles were observed while they were immersed in the water and with use of a stereomicroscope--with the assistance of which they were drawn. In six sides the intramuscular nerve supply was also examined carefully and drawn. The results were as follows. 1. The nerves to the four deep muscles of the forearm extensors arose usually from the deep branch of the radial nerve after emerging the supinator muscle and sending branches to superficial forearm extensors. In some cases a nerve or nerves to the superficial forearm extensors were observed arising from the deep branch of the radial nerve after sending one or more branches to the deep forearm extensor muscles, or from the branches to the deep muscles themselves. However they were split easily from the deep branch of the radial nerve and from the branches to the four deep forearm extensors proximally near to the emerging of the deep branch from the supinator muscle. Therefore, it was considered to be constant that the nerves to the four deep forearm extensors arose from the deep branch of the radial nerve after branching to the superficial forearm extensors. 2. The radial group of the deep forearm extensors (the abductor pollicis longus and the extensor pollicis brevis muscles) was innervated usually by one branch that arose from the deep branch of the radial nerve just after emerging from the supinator and giving off branches to the superficial forearm extensors. This branch ran on the dorsal (extensor) surface of the abductor pollicis longus muscle distally, sending many twigs to this muscle, and entered into the muscle at various distances from the origin (Figs. 1-6). The abductor pollicis brevis muscle was innervated by some twigs that ran usually inside but occasionally outside of the abductor pollicis longus muscle (Figs. 7-10).(ABSTRACT TRUNCATED AT 400 WORDS)     

用于显露前臂骨间膜的桡骨背侧入路应用解剖

目的 找出显露前臂骨间膜的最佳入路.方法 用卡尺测量了30例成人上肢,测量项目如下:桡骨头至旋后肌腱弓处骨间背神经的长度(LHA);桡骨头到旋后肌管下口之间骨间背神经的长度(LHS);骨间背神经从旋后肌管下口至桡骨外缘的距离(DSR);骨间背神经从旋后肌管下口至尺骨内缘的距离(DSU);骨间背神经最外侧分支穿拇长展肌处至桡骨外缘的距离(DSP).结果 LHA、LHS、DSR、DSU和DSP的测量结果分别为19.3±4.4mm(11mm～29mm)、53.4±5.2mm(45mm～62mm)、9.7±3.1mm(4mm～15mm)、22.8±3.5mm(20mm～28mm)和7.5±1.6mm(5mm～9mm).牵开拇长展肌、拇短伸肌和拇长伸肌,于桡侧腕短伸肌与指伸肌之间显露前臂骨间膜中1/3和远1/3段.结论 桡骨背侧入路可较少剥离肌肉和软组织,能方便、安全显露前臂骨间膜中1/3和远1/3段.     

骨间后神经受压的解剖学基础

目的阐明骨间后神经(PIN)卡压的原因及其手术治疗提供解剖基础。方法30侧尸体上肢标本,将PIN分为3段(即桡管段、旋后肌管段和旋后肌管后段)观察其肌支的分支情况;用卡尺对桡管(RT)、旋后肌管(ST)和桡侧腕短伸肌腱弓(AECRM)的形态和大小进行了观测,并对ST入口和出口的体表投影定位。结果ST入口和出口的宽度分别为(14.1±2.1)mm和(6.2±1.7)mm,长度为(35.0±6.9)mm。PIN从桡骨头至旋后肌腱弓(AF)和PIN从旋后肌穿出处的长度分别为(19.3±4.4)mm和(53.4±5.2)mm。AF的53.3%由肌性加腱性组织构成,23.3%由腱性组织构成,23.3%由肌组织构成。70%旋后肌远侧缘由腱性组织构成,所有AECRM均是腱性。桡骨背侧桡骨头下方1示指宽和3示指宽分别为ST的入口和出口的体表投影。结论本文提供的RT、ST和AECRM详细形态资料,对于PIN卡压的诊断和手术治疗具有指导意义。     

骨间后神经穿桡管远端处的解剖特点及其临床意义

目的：了解骨间后神经穿旋后肌后可能的卡压位置及临床意义,方法：在2倍放大镜下解剖骨间后神经穿旋后肌后的行程,分支,可能卡压位置以及前臂活动对其影响。结果：骨间后神经穿旋后肌后恒定地分尺仙支和桡侧支;旋后肌远侧缘和拇短伸肌,拇长展肌浅面的腱性肌纤维结构可能是致卡压的解剖结构,前臂伸肌群的活动可 诱发上述结构卡压骨间后神经,结论：在桡管远端同样存在卡坟骨间后神经的解剖结构,必要时应手术探查,松解。     

Distal variations of the neurovascular pedicle of the serratus anterior muscle as a flap

The serratus anterior muscle has recently been suggested as a versatile and reliable flap for reconstruction of complex craniofacial and neck lesions, extremity and sacroiliac region injuries, as well as intrathoracic and extrathoracic reconstruction procedures. The muscle has been used as a microvascular flap or a pedicled transfer and has been transferred in combination with other muscles, bones, and skin. We performed 15 dissections of adult axilla regions that were examined under ×3.5 loupe magnification to collect anatomic data regarding the neurovascular pedicle of the serratus anterior muscle. The serratus muscle and fascia were found to have a dual blood supply, with the upper part supplied by the lateral thoracic artery and the lower part by terminal branches of the thoracodorsal artery. The lateral thoracic artery was noted to supply the upper four slips but it extended into the lower serratus anterior muscle in two cases. Seven branching patterns were found in the lower serratus anterior muscle. In type I, the only branch of serrati proceeded over the long thoracic nerve. Type II had the only branch of serrati proceeding under the long thoracic nerve. In type III, double branches of serrati proceeded over the long thoracic nerve; while in type IV branches of serrati ran with a double branch under the long thoracic nerve. In type V, three serrati branches proceeded over the long thoracic nerve. Type VI serrati branches were branches of thoracodorsalis, which was hypoplastic, and the supply was maintained from the lateral thoracic artery. In type VII, one serrati branch ran over the long thoracic nerve. There was no connection between the branches of serrati and the branches of the lateral thoracic artery. The length of the long thoracic nerve, the number of motor axons and the vascular network in anatomic proximity to this nerve make it an expendable but powerful source of reconstructions of head, neck, chest wall and extremity defects. Results of this study provide an anatomic framework to improve current reconstructive or aesthetic procedures on the serratus anterior neurovascular structures.     

Nerve supply of the brachioradialis muscle: surgically relevant variations of the extramuscular branches of the radial nerve

The brachioradialis muscle is utilized in tendon-transfer operations, carried out for a variety of purposes. The extramuscular branches of the radial nerve to the brachioradialis were dissected and studied in 43 embalmed cadaveric specimens. The number of primary and secondary branches and the spatial locations of their origins and muscle-entry points was determined for each specimen. All distances were measured relative to the lateral epicondyle. A wide anatomic variation was observed in both the nerve branching pattern as well as the number and locations of muscle-entry points. A single primary nerve branch was found in 20 specimens, or 46.5% of the cases. On an average, single primary nerve branches arose from the radial nerve 30 mm proximal to the lateral epicondyle. In 16 of these cases, the primary branch splits into two to four secondary branches, and in four cases there was only one branch entering the muscle. Seventeen specimens had two primary branches whose origin points were separated by 5 to 40 mm with an average of 15 mm. In seven of these seventeen cases one or both of the primary branches split into secondary branches. Six specimens had three primary branches; the origin points of the most proximal and the most distal branch were separated by up to 30 mm with an average of 13 mm. Excluding the four cases with extensive fanning into multiple thin branches, the number of muscle-entry points ranged from 1 to 4 (mean 2.7). The locations of the muscle-entry points for all specimens were widespread ranging from 50 mm proximal and 40 mm distal to the lateral epicondyle with an average at 6 mm proximal to the lateral epicondyle. The greatest distance between muscle-entry points was 50 mm in a single specimen. In surgical procedures involving dissection of the brachioradialis muscle more proximal than 50 mm distal to the elbow, the extramuscular branch(es) of the radial nerve branches to the brachioradialis may be at risk.     

胸小肌移植重建拇对掌功能的神经解剖学研究

目的为临床应用胸小肌移植重建拇对掌功能手术过程中神经吻接提供解剖学依据。方法解剖观测胸内侧神经及尺神经深支分支特点,比较相关神经有髓神经纤维数目,确定手术过程中神经吻接。结果胸内侧神经为胸小肌的主要支配神经,其在第3肋间隙近锁骨中线处入胸小肌,有髓神经纤维计数为(868±130)根;尺神经深支穿出内侧肌间隔后在第3、4掌骨间隙分别发出两明显肌支,其有髓神经纤维计数分别为(394±49)根、(708±78)根;P3L4(尺神经深支在第4掌骨间隙的分支,其分布于第3骨间掌侧肌和第4蚓状肌)与胸内侧神经、正中神经返支有髓神经纤维数目都比较接近。结论胸小肌移植重建拇对掌功能手术中,在切取胸小肌时以胸内侧神经作为供体神经,以第3肋间隙与锁骨中线交点为标记寻找该神经;尺神经深支中P3L4肌支与胸内侧神经吻合最匹配。     

股神经和闭孔神经肌支转位的解剖学测量和神经纤维定量

目的　探索股神经肌支转位修复闭孔神经损伤与闭孔神经肌支修复股神经损伤的应用解剖。 方法　游标卡尺测量20具成人尸体股神经和闭孔神经肌支的长度;6具死亡3~10 h内尸体,其股神经和闭孔神经的肌支经Karnovsky-Roots法染色后,图像分析仪测量它们的横切面积和神经纤维数量。 结果　股神经肌支中股内侧肌长支最长,近端横断面积最大;闭孔神经肌支中股薄肌支最长,大收肌支近端横切面积最大。每条肌支内均以躯体运动纤维含量最高,股神经肌支中股内侧肌长支躯体运动纤维数量最多,而闭孔神经肌支中大收肌支最多,其次是股薄肌支。各肌支中γ-薄髓神经纤维的含量,股神经的肌支中以股内侧肌短支和股直肌支较高;而闭孔神经肌支中短收肌支含量最高。 结论　基于各肌支长度、近端横断面积和神经纤维数量的综合考虑,股神经和闭孔神经损伤修复中,股内侧肌长支和股薄肌支宜为供体神经;股内侧肌短支和股直肌支以及大收肌支宜为受体神经。     

家兔面神经颅外段的显微解剖

目的　探讨家兔面神经颅外段的主干及分支特点。 方法　健康家兔15只,在显微镜下解剖家兔面神经,并对其形态特点进行观测。 结果　家兔面神经出茎乳孔后分出耳后支、二腹肌支、茎突舌骨肌支及面神经主干。兔面神经主干在面部的分支有颞支、颧支、颊支、下颌缘支和颈支,其中颧支与颊支关系密切,走行过程中合成一干,然后在口角后缘分离。 结论　家兔面神经颧支与颊支在耳廓下缘前部位到口角后缘之间,分支少,神经干较粗,便于进行面神经缺损修复动物模型的建立。     

The course and branching pattern of the deep branch of the radial nerve in relation to the supinator muscle in fetus elbow

We aimed to make first demonstration of the course and branching pattern of deep branch of the radial nerve (DBRN) in relation to the supinator muscle in the forearms of fetuses and make morphological measurements in both fetuses and adults. We carried out dissection on 80 radial nerves from 20 adult cadavers (16 males and 4 females), ranging from 30 to 56 years old and 20 formalin-fixed, spontaneously aborted fetuses (10 males and 10 females) without detectable malformations, ranging from 20 to 37 weeks of gestation. There were three different branching patterns of the DBRN in fetuses. It divided its terminal branches at entrance of the supinator in 2 (5%), after entry of the supinator in 4 (10%) and after the supinator in 34 (85%) forearms. The course was bilaterally same in fetuses. Dividing pattern at the entrance of the supinator was not seen in adults. Only 4 (10%) were seen at after entering to the supinator and 36 (90%) were seen at after the supinator. We saw in fetuses neither fibrous band deep from the extensor carpi radialis longus nor upper border of the supinator. We assume that these fibrous structures appear after birth, perhaps favored by physical exercise, such as repeated pronation–supination movements. We think that it is one of the reasons why DBRN compression has never been reported in children. This is the first fetal study about the course and branching pattern of the DBRN and there is a constant ratio (mean 4.3) between the measurements of the fetuses and adults.     

锁骨上神经在锁骨上区域分布的解剖观察

目的 探讨锁骨上神经在锁骨上区域的分布规律,为临床手术提供参考。方法 前瞻性研究。纳入2017年9 月—2018 年12月保定市第一中心医院西院骨五科在骨折复位内固定手术中同时完成锁骨上神经解剖的锁骨骨折患者30例(30侧),其中男16例、女14例,年龄18 ～ 46 岁。30 例手术均取锁骨上切口,术中仔细分离出锁骨上神经各个分支,统计每例的神经分支数目,并了解其在锁骨上区域的走行及分布关系。以锁骨两端中点连线为锁骨横轴,在C形臂X线机透视下,术中用克氏针标记锁骨上神经各分支横跨锁骨上缘处;将锁骨横轴全长视为单位“1”,以锁骨横轴内侧端为 “0”点、外侧端为 “1”点,在X线影像上测量锁骨上神经各分支标记点到“0”点的距离,进而比较分支数目不同时,其内、外分支分布具体位置的差异。结果 30例锁骨区域解剖显示,有 15例锁骨上神经拥有三支分支(内、中、外支),14例拥有两支分支(内、外支),1例拥有一支分支(中支)。利用相对测量方法测量出15例有三支分支患者解剖观察结果示外侧支出现于0.64±0.081、中间支出现于0.47±0.12、内侧支出现于0.27±0.08 ;14例有两支分支患者解剖观察结果示外侧支出现于0.61±0.07、内侧支出现于0.30±0.07;一支分支患者解剖观察结果示中间支出现于0.57。统计学分析显示,不同分支数目患者间内、外支神经分支分布区域差异均无统计学意义(P值均＞0.05)。结论 锁骨上神经在锁骨上区域出现的部位具有一定规律,掌握这一规律可为术中避免损伤锁骨上神经及二期钢板取出提供一定的帮助。     

An anatomic study of structure and innervation of the serratus anterior muscle

Background

The structure and function of the serratus anterior muscle are partitioned into three parts. If the morphological characteristics in each part can be demonstrated in more detail, the cause of dysfunction will probably be identifiable more accurately. The purpose of this study was to demonstrate the details of the structure and innervation in each part of the serratus anterior muscle.

Materials and methods

This macroscopic anatomic study was conducted using ten sides from five cadavers. The structure and innervation in each part of this muscle were examined.

Results

In the superior part, the independent branch was divided from a branch innervating the levator scapulae muscle. In the middle part, the long thoracic nerve descended on one-third of the anterior region between the origin and insertion. In the inferior part, the long thoracic nerve which ramified into many branches and branches from the intercostal nerves were distributed on all sides.

Conclusion

This study demonstrated that the innervation of the serratus anterior muscle was different in each part. The difference indicates that the superior part has an intimate relation with the levator scapulae muscle while the middle and inferior parts could be the actual serratus anterior muscle. Moreover, the distribution of branches from the intercostal nerves shows that the inferior part has a connection with some trunk elements. Understanding these characteristics of innervation is useful to identify the cause of dysfunction. In addition, we assert that the constant distribution of branches from the intercostal nerves is significant for the morphology.     

Gross anatomic evidence of partitioning in the human fibularis longus and brevis muscles

Evidence from a variety of studies suggests that many mammalian muscles are partitioned with respect to their architecture and innervation. Each of these specific muscle subvolumes is innervated by an individual muscle nerve branch, contains motor unit territories with a unique array of physiological attributes and has been known as a neuromuscular compartment or segment. This gross anatomic study investigated for evidence of neuromuscular segmentation in human fibularis (peroneus) longus and brevis muscles. Forty-three legs (24 left, 19 right) from embalmed adult cadavers were dissected. Any architectural segments within these muscles were identified. The specific innervation patterns of these muscles were also described. The fibularis longus muscle was consistently found to have connective tissue partitions that separated it into four parts: anterior superficial, anterior deep, posterior superficial, and posterior deep. The innervation pattern of this muscle was consistent with the segments defined by the connective tissue partitions. There were consistently four primary motor branches, each supplying a specific portion of the fibularis longus muscle. While a typical branching pattern was recognized, there was some variability as to the order of these branches as they originated. The fibularis brevis muscle was consistently found to have a central connective tissue partition that separated it into two portions: anterior and posterior. In 91% of the fibularis brevis muscles, there were two primary motor branches, one for each of the two segments of the muscle. In the other 9%, only one primary motor branch supplying the muscle could be identified. © 1996 Wiley-Liss, Inc.     

Anatomic basis of dorsoradial approach for radioulnar synostosis

The object of this study was to identify the best approach for exposing the radioulnar interosseous membrane while protecting the posterior interosseous n. (PIN). Twenty paired upper limbs were used to obtain measurements of the PIN and expose the distal two-thirds of the interosseous membrane in the forearm through a dorsoradial approach. The length of the PIN from the radial head to the arcade of Frohse (AF) was 26.5 ± 1.6 mm in males and 25.3 ± 1.1 mm in females. The length of the PIN between the radial head and the point where the PIN exits from the supinator was 66.7 ± 4.7 mm in males and 64.0 ± 2.5 mm in females. The length of the PIN covered by the supinator was 44.0 ± 0.5 mm in males and 37.0 ± 0.5 mm in females. The distance between the point where the PIN exits from the supinator and the lateral margin of the radius was 15.0 ± 0.9 mm in males and 14.5 ± 0.9 mm in females. The distance between the exit point of the PIN from the supinator and the lateral margin of the ulna was 18.2 ± 0.6 mm in males and 17.9 ± 0.7 mm in females. The distance from the point where the most lateral branch of the PIN entered the abductor pollicis longus (APL) to the lateral margin of the radius was 3.5 ± 0.5 mm. In 20 cadaveric upper limbe, the middle and distal portions of the interosseous membrane were exposed through the interval between the extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) m., after the origine of the extensor pollicis brevis (EPB), and extensor pollicis longus (EPL) mm. had been elevated from the lateral margin of the radius. The present study suggests that usina dorsoradial approach facilitates exposure of the middle and distal portions of the interosseous membrane.     

腹外斜肌的神经入肌点定位与肌内神经分布研究

目的　对人腹外斜肌的神经入肌点定位和肌内神经染色观察，为其临床应用提供形态学资料。 方法　成尸11具定位神经入肌点和5具行Sihler’s 肌内神经染色。 结果　腹外斜肌受下8对肋间神经外侧肌支支配，各个肌齿的神经入肌点距离相应肌齿起端中点(1.54±0.33)cm，位于锁骨中线与第5肋下缘的交界处至腋后线与第11肋下缘交界处的连线上。Sihler’s染色显示支配腹外斜肌的肋间神经外侧肌支入肌后分出小分支分布到各肌齿的起端1/3，然后约在各肌齿的近、中1/3交界处分出2支二级神经分支，即上支与下支，它们分出小分支分布到各肌齿的中间1/3，相邻两个肌齿的上支与下支在各肌齿中远部形成“U”形吻合，从“U”形吻合弓上分出小分支分布到各肌齿的止端1/3。在腹外斜肌上半部，各肌齿的神经分支分布到相应的肌齿，但在腹外斜肌下半部，上一肌齿的远侧下份是由下一肌齿的神经分支(上支)分布。 结论　①为临床上腹壁局部麻醉和术后切口疼痛的神经阻滞提供指导意义；②腹外斜肌中远部从上至下形成“波浪形”的神经分支密集区；③腹部手术切口建议不要超过四个肌齿。