The course of the inferior gluteal nerve and surgical landmarks for its localization during posterior approaches to hip

The position of the inferior gluteal nerve (IGN) makes it vulnerable to iatrogenic injury during posterior and posterolateral approaches to the hip. Although the posterior approach has been reported to be the most frequently used technique, it is most likely to be associated with damage to the IGN. As there is scant information in the literature regarding the course and the anatomic relationships of the IGN, we aimed to investigate the anatomic course of the IGN and define the anatomical landmarks that can be used by surgeons during posterior approaches to the hip. Thirty-six gluteal regions from adult fixed cadavers were used for this study. A triangular-shaped anatomic area that contains the IGN was defined. This geometric area was formed by connecting the following points: posterior inferior iliac spine (PIIS) (apex), ischial tuberosity (IT) and greater trochanter (GT). This triangle can further be divided into two, the upper triangle being the “danger zone” since it contains the IGN and its branches. The closest mean distance between the point of IGN origin and the PIIS, IT and the GT was 3.2, 4.8 and 5.4 cm, respectively. In all specimens, the nerve entered the deep surface of the gluteus maximus approximately 5.4 cm from the apex of the GT and approached the GT as close as 0.8 cm, on average. Based on our study, dividing the gluteus maximus with standard techniques may damage the IGN. Posterior minimally invasive approaches to the hip should take into account the point of entry of the IGN into the gluteus maximus. Localization of the IGN by using the anatomic triangle defined in this study may decrease surgical morbidity.     

臀区穿支皮瓣的应用解剖学研究

目的:为臀区穿支皮瓣的临床应用提供解剖学基础。方法:6具(12侧)动脉灌注明胶-氧化铅混悬液的新鲜成人整尸标本,解剖观测臀区外径≥0.5mm的穿支,测量其管径及其走行、分支、分布情况等。取下整个臀区被覆组织拍摄X线片,观测皮动脉的数量以及彼此之间的吻合情况等。利用Photoshop与ScionImage分析穿支供血的趋向性及每个分支的供血面积等。结果:臀上、臀下动脉直径≥0.5mm的穿支数量分别为平均(5±2)支和(8±4)支,所有的臀上动脉和90%的臀下动脉的分支都是肌皮穿支,这些穿支的平均内径为(0.6±0.1)mm。臀上、臀下动脉穿支在皮肤的平均分布范围分别是(69±56)cm2和(177±38)cm2。臀上动脉穿支主要分布在髂后上棘和大转子的连线的内侧2/3;而臀下动脉的穿支多在臀区与臀皱褶平行的水平中部1/3处。结论:臀区的皮肤穿支密集,营养皮肤面积较大,以臀上、臀下动脉穿支为蒂设计的穿支皮瓣可用于乳房重建,骶骨、髋骨及会阴区重建等。     

Relationship of inferior gluteal nerves and vessels: target for application of stimulation devices for the prevention of pressure ulcers in spinal cord injury

A study was carried out to determine whether the location of the inferior gluteal nerve could be reliably predicted using external anatomy or vascular imaging. This study was motivated by our group’s development of an electrical stimulation system to provide direct gluteal stimulation in paralyzed individuals, in particular those with spinal cord injury (SCI). Pressure ulcers are a common complication for many individuals with reduced mobility. Numerous approaches have been employed to treat and prevent pressure ulcers; however no procedure or nursing care regimen has been successful in eradicating them completely. Our group seeks to prevent skin breakdown in susceptible patients by direct electrical stimulation of the paralyzed gluteal muscle, leading to improved circulation and increased muscle mass (hypertrophy) in the treated area. Currently, percutaneous electrodes are placed through an extensive probing process to select the motor point of the target muscle. We examined 15 cadaver gluteal regions to identify the relationship between the internal anatomy of the inferior gluteal artery and nerve as well as the relationship to external anatomic landmarks. The cadavers displayed variability with regard to the morphology of the branches of both nerve and artery. Furthermore, there did not appear to be any relationship between the relative positions of the nerve and artery. However, the potential target area of the proximal origin of the inferior gluteal nerve could reliably be predicted from the external bony anatomy of the lower pelvis.     

臀部肌肉注射数字化解剖学研究

目的为临床上确定臀部肌肉内注射的最佳部位及深度提供数字化解剖学依据。方法 (1)23具防腐标本,解剖观测臀肌注射位置与血管干、坐骨神经的距离及软组织厚度;(2)6具明胶-氧化铅灌注的新鲜整尸标本,CT扫描后,行盆部三维重建。结果三分法臀部肌内注射点处的软组织总厚度为(6.63±1.06)cm,臀肌间隙至髂骨翼骨膜的距离为(4.37±0.62)cm,注射针体距臀上血管主干和坐骨神经的距离分别为(5.87±0.93)cm和(7.46±0.94)cm;十字法臀部肌内注射定位点距坐骨神经的距离为(3.63±0.68)cm。结论连线法臀部肌内注射简易而安全,但目前成人常用的注射针头(2.7～4.9cm)普遍偏短,建议选择针梗长6cm以上的针头。     

臀下神经转位阴部神经的应用解剖

目的：为重建单纯脊髓圆锥或阴部神经损伤后的会阴部功能提供解剖学基础。方法：对成人尸体的臀下神经和阴部神经进行了观测。结果：臀下神经以1支(45．00％)或2支(46．67％)从盆腔穿出为多，其中85．00％穿梨状肌下孔；其穿出点的位置主要在髂后上棘与坐骨结节连线的中1／3(50．00％)或上、中1／3交界处(48．33％)。神经干的长大于3cm，与阴部神经穿出处相距仅约2cm。阴部神经出盆处主要在髂后上棘与坐骨结节连线中1／3(46．67％)或中、下1／3交界(50．00％)。结论：两神经出盆处位置接近，臀下神经的长度足以直接与阴部神经缝接，用脊髓起源节段高的臀下神经转位脊髓起源节段低的阴部神经，切实易行。     

Arterial supply to the sciatic nerve in the gluteal region

The arterial supply to the sciatic nerve was investigated in 20 human lower limbs (10 right, 10 left) from 20 cadavers (14 females, aged 84 +/- 9.6 years, range 66-95 years: 6 males, aged 80 +/- 8.2 years, range 70-90 years). In all limbs examined at least 1 sciatic artery could be identified supplying the sciatic nerve in the gluteal region. In total 28 sciatic arteries were identified, of which 14 arose from the medial circumflex femoral artery, 11 from the inferior gluteal artery, 2 from the first perforating artery, and 1 from the internal pudendal artery. In 5 limbs, 2 sciatic arteries were observed, being independent branches from the medial circumflex femoral and inferior gluteal arteries in 4 limbs and separate branches of the medial circumflex femoral artery in 1 limb. In 1 limb, 4 sciatic arteries were observed: 1 from the inferior gluteal artery, 2 from the medial circumflex femoral artery, and 1 from the first perforating artery. In the remaining 14 limbs a single sciatic artery was observed, which in one case arose from the internal pudendal artery, a previously unreported observation.     

Morphological aspects of the inferior suprarenal artery

The study was performed on 120 cases, and evaluated the origin, caliber at the origin, course, place of termination and distribution of the inferior suprarenal arteries, together with their point of entry into the glandular parenchyma. Most often, the inferior suprarenal artery originated from the trunk of the renal artery, prior to its terminal division. Other possible origins were: as a terminal branch of the renal artery, from one of the terminal branches of the renal artery (most often from the anterior division and rarely from the posterior one), as a common trunk with the superior polar renal artery, from a supplementary renal artery (more often from the superior and rarely from the inferior one), directly from the aorta, either as an individual branch, as a common trunk with the superior polar renal artery or as a common trunk with the middle suprarenal artery. Rarely the inferior suprarenal artery may originate from the genital artery or, also very rarely, from the celiac trunk, either individually or as a common trunk with the middle suprarenal artery. Usually, the inferior suprarenal arteries originating from the aorta or the renal artery have a larger caliber than those from other arterial sources. Most often, we found two or three arterial branches as inferior suprarenal arteries, so we may speak of inferior suprarenal arteries or an inferior suprarenal arterial pedicle.

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Electronic Supplementary Material The french version of this article is available in the form of electronic supplementary material and can be obtained by using the Springer Link server located at

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Aspects morphologiques de l'artère surrénalienne inférieure

Résumé L'étude a été conduite sur 120 cas permettant l'étude de l'origine, du diamètre à l'origine, du trajet, de la terminaison et de la distribution des artères surrénaliennes inférieures (ASI) ainsi que de leur point de pénétration dans le parenchyme glandulaire. Le plus souvent, l'ASI naissait du tronc de l'artère rénale avant sa division en branches terminales. Mais cette origine était variable : l'ASI pouvait dans certains cas être la branche terminale de l'artère rénale, elle pouvait naître de l'une des branches terminales (le plus souvent de la branche antérieure, plus rarement de la branche postérieure) ou d'un tronc commun avec l'artère polaire supérieure. Lorsqu'il existait plusieurs artères rénales, l'ASI naissait souvent de l'artère rénale supérieure et, plus rarement, de l'artère rénale inférieure. Elle pouvait naître enfin directement de l'aorte, soit directement, soit par un tronc commun avec l'artère polaire supérieure ou avec l'artère surrénalienne moyenne. Il était rare qu'elle prenne naissance de l'artère génitale. Très rarement enfin, c'était une branche du tronc cliaque, directement ou par un tronc commun avec l'artère surrénalienne moyenne. Habituellement, lorsque les ASI naissaient de l'aorte ou de l'artère rénale, leur calibre était plus important que lorsqu'elles naissaient d'autres sources artérielles. Le plus souvent nous avons trouvé deux ou trois branches artérielles constituant les ASI, si bien qu'il nous semble préférable d'utiliser le terme "artères surrénaliennes inférieures" ou "pédicule artériel surrénalien inférieur".

     

臀肌悬带解剖学测量及其临床意义

目的测量臀肌悬带的相关解剖学参数,为国人解剖学数据提供资料,同时为临床通过切除臀肌悬带降低坐骨神经麻痹发生率提供解剖学依据。方法选择国人成人尸体下肢标本24例,测量其臀肌悬带以及其与坐骨神经、第1穿动脉、股骨大转子尖和坐骨结节的关系。结果臀肌悬带的长度为(8.68±0.80)cm;悬带的近侧端和股骨大转子尖之间的距离为(6.57±0.92)cm;坐骨结节后尖的臀大肌纤维和悬带近侧端距离为(5.56±0.71)cm;悬带近侧2/3末端与坐骨结节的连线与坐骨神经夹角为(42.2±5.4)°;坐骨神经外侧缘与悬带近、远侧端之间的最小横向距离分别为(2.93±0.56)cm和(2.30±0.42)cm;大转子尖和第1穿动脉的距离为(10.84±0.54)cm;大转子尖和第1穿动脉升支的距离为(8.77±0.58)cm;悬带近端到第1穿动脉的距离为(3.84±0.53)cm;悬带近端到第1穿动脉升支的距离更近,为(1.78±0.93)cm。结论切断悬带近侧端约6cm就足以释放坐骨神经压力而不必完全切除悬带。第1穿动脉特别是其升支与臀肌悬带极为接近,极易受损,解剖分离后者与周围结构时,应极为谨慎。     

基于三维CT的臀上动脉解剖学研究

目的　通过三维CT血管成像(three-dimensional computed tomographic angiography,　3DCT-A)描述臀上动脉(superior gluteal artery,SGA)的位置及解剖形态。 方法　纳入114例(228髋)患者的3DCT-A数据做以下研究：(1)观察SGA的显影情况;(2)观察SGA的起始、分支及走行特点;(3)定义　SGA盆外部分主干为：出盆点到深支止点或折弯点(当深支为1支时)的一段SGA,测量其长度并进行不同性别间的比较;(4)测量SGA盆外部分主干到骨盆骨性标志(髂后上棘、坐骨大切迹起点、坐骨棘)、骨性标志间连线(坐骨棘与髂结节间)的距离,并进行不同性别间的比较。 结果　(1)94例患者的SGA显示清晰;(2)所有患者的SGA均来源于髂内动脉;(3)28髋的SGA在出盆前近出盆处发出分支;(4)SGA出盆点到坐骨大切迹起点的距离、到坐骨棘的距离在男女患者间均存在统计学差异;(5)SGA盆外部分主干与髂结节和坐骨棘间连线成近似平行关系。 结论　通过3DCT-A了解SGA的位置及解剖形态,能为预防　SGA的医源性损伤提供帮助。     

Anatomic considerations and the relationship between the piriformis muscle and the sciatic nerve

Stating background  The piriformis syndrome is one of the non-discogenics causes of sciatica. It results from the compression of the sciatic nerve (SN) by the piriformis muscle (PM) in the neutral and piriformis stretch test position. The evidence of the increase in pain in the test position requires a detailed anatomical study addressing the changes that occurred in the SN and PM anatomy during the test position. The aim of this study is to examine this relationship morphometrically. Materials and methods  A total of 20 right and left lower limbs of ten adult cadavers were examined. The SN and the PM were made visible. The location of the SN was evaluated with respect to the consistent bony landmarks, including the greater and the lesser trochanter of the femur, the ischial tuberosity, the ischial spine of the hip bone, the posterior inferior iliac spine of the hip bone and the posterior superior iliac spine of the hip bone. The study was done in both neutral and test positions (i.e., 30° adduction 60° flexion and approximately 10° medial rotation position of the hip joint). Results  The width of the greater sciatic notch was 63.09 ± 13.59 mm. The length of the lower edge of the PM was 95.49 ± 6.21 mm, and whereas the diameter of the SN where it emerged from the infrapiriforme was 17.00 ± 3.70 mm, the diameter decreased to 11.03 ± 2.52 mm at the level of the lesser trochanter of the femur. The SN intersected the PM most commonly in its medial second quarter anatomically. The vertical distance between the medial edge of the SN–PM intersection point and the ischial tuberosity was 85.62 ± 17.23 and 72.28 ± 7.56 mm (P < 0.05); the angle between the SN and the transverse plane was 66.36° ± 6.68° and 71.90 ± 8.48° (P < 0.05); and the vertical distance between the medial edge of the SN and the apex of the ischial spine of the hip bone was 17.33 ± 4.89 and 15.84 ± 4.63 mm (P > 0.05), before and after the test position, respectively. Conclusion  This study provides helpful information regarding the course and the location of the SN. The presented morphometric data also revealed that after stretch test position, the infrapiriforme foramen becomes narrower; the SN becomes closer to the ischial spine of the hip bone, and the angle between the SN and the transverse plane increases. This study confirmed that the SN is prone to be trapped in the test position, and diagnosis of this situation requires dynamic MR and MR neurography study.     

肘下动脉穿支皮瓣的解剖学观察

目的为肘下动脉穿支皮瓣移位修复肘部软组织缺损提供解剖学基础。方法在30侧经动脉内灌注红色乳胶的成人上肢标本上观测肘下动脉的起源、走行、分支与分布,另在1侧新鲜标本上进行摹拟手术设计。结果肘下动脉在肱骨内、外上髁连线中点下方(3.98±0.86)cm处,自桡动脉(占50%)、桡侧返动脉(占40%)和肱动脉(占10%)起始后,斜向外下方走行,其轴线位于肘下动脉的起始处与桡骨背侧结节(Lister结节)的连线上。肘下动脉向远侧分布达15 cm,并与桡动脉的远侧穿支、桡侧返动脉的肘外侧部皮支相互吻合。肘下动脉外径0.8 mm。结论以肘下动脉为蒂设计皮瓣,局部转移可修复肘部各方的软组织缺损。     

The inferior laryngeal nerve: surgical and anatomic considerations. Report of 251 thyroidectomies

This surgical anatomic study aimed to determine (1) the anatomic relation of the laryngeal inferior nerve with the inferior thyroid artery, (2) the existence of extralaryngeal branches of division of the nerve and (3) the size of the nerve seen macroscopically. Two hundred and fifty-one patients underwent thyroid surgery during a period of 30 months. There were 50 males and 201 females. The male population underwent 28 total thyroidectomies, 13 left lobectomies and 9 right lobectomies. The female population underwent 124 total thyroidectomies, 33 left lobectomies and 44 right lobectomies. On the right side: the nerve was found superficial to the artery in 70.24% of females and 51.35% of males, the nerve was divided in 23.81% of females and 21.62% of males and seemed unusually thin in 14.29% of females and 5.41% of males. On the left side: the nerve was found superficial to the artery in 87.26% of females and 95.12% of males, the nerve was divided in 15.29% of females and 14.63% of males and seemed unusually thin in 10.83% of females and 2.44% of males. In conclusion, the inferior laryngeal nerve is characterized by its important anatomic variations, especially on the right side. These variations might be different even between males and females. Knowledge of these variations is very important in order to best identify and preserve the inferior laryngeal nerve during thyroid surgery.

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Electronic Supplementary Material The french version of this article is available in the form of electronic supplementary material and can be obtained by using the Springer Link server located at .

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Le nerf laryngé inférieur: considérations anatomiques et chirurgicales. A propos de 251 thyroïdectomies

Résumé Il s'agit d'une étude anatomique per-opératoire ayant pour but de préciser (1) les rapports du nerf laryngé inférieur avec l'artère thyroïdienne inférieure, (2) l'existence de branches de division nerveuses extra-laryngées et (3) une appréciation subjective du calibre macroscopique du nerf. 251 patients ont bénéficié d'une chirurgie thyroïdienne (50 hommes et 201 femmes) sur une période de 30 mois. Pour les hommes ont été réalisées 28 thyroïdectomies totales, 13 lobo-isthmectomies gauches et 9 lobo-isthmectomies droites. Pour les femmes ont été réalisées 124 thyroïdectomies totales, 33 lobo-isthmectomies gauches et 44 lobo-isthmectomies droites. Du côté droit, le nerf était superficiel par rapport à l'artère dans 70,24% des cas chez les femmes et 51,35% chez les hommes, il était divisé dans 23,81% des cas chez les femmes et 21,62% chez les hommes et il était anormalement fin dans 14,29% des cas chez les femmes et 5,41% chez les hommes. Du coté gauche, il était profond dans 87,26% des cas chez les femmes et 95,12% chez les hommes, il était divisé dans 15,29% des cas chez les femmes et 14,63% chez les hommes et il était anormalement fin dans 10,83% des cas chez les femmes et 2,44% chez les hommes. En conclusion, le nerf laryngé inférieur est caractérisé par ses grandes variations anatomiques, en particulier du côté droit. De plus ces variations sont possiblement différentes entre les sexes. La connaissance de ces variations est indispensable pour le repérage et la préservation du nerf au cours de la chirurgie thyroïdienne.

     

An anatomical study of the recurrent laryngeal nerve: its branching patterns and relationship to the inferior thyroid artery

Abstract: The aim of this study was to provide information about the morphology and topography of the recurrent laryngeal nerve (RLN), its external features and branches, as well as its relationship to the inferior thyroid artery, the inferior horn of the thyroid cartilage and the thyroid gland. The RLNs in 50 adult cadavers (100 sides) were dissected and analyzed. A communicating loop connecting one branch of the RLN to another or a twig originating from the cervical sympathetic trunk was present in 13 of 100 sides. A double left RLN appeared in 2 sides; a right non-recurrent inferior laryngeal nerve appeared in one side. All of the RLNs, including looped ones, bifurcated into laryngeal branches and extralaryngeal branches, with most of the former further dividing into the anterior and posterior branches entering the larynx. The relations of the RLN to the inferior thyroid artery, the inferior horn of the thyroid cartilage and the thyroid gland were inconstant. The information gained from this study will be of value in thyroid surgery.     

Anastomosis between the inferior alveolar artery branches and submental artery in human mandible

The mental artery displays several branches internal to the anterior region of the mandible as confirmed by macroscopic observation and computed tomography. The inferior alveolar artery formed complex branches and divided into mental and incisive branches, which were found in the right internal side of the mandible of one male cadaver (88 years old). The branches of these two arteries ran through the bony lingual canal to the lingual foramen between the canine and premolar region of the inner surface of the mandible body, where they emerged to enter the mylohyoid and anterior belly of the digastric muscles and communicate with the submental artery. The observation of the anastomotic artery is considered important for surgical placement of dental implants in the mandibular region.     

梨状肌上孔内血管损伤致臀内上部坏死的解剖学基础

目的:分析研究髋关节手术损伤臀上血管后并发臀内侧上部坏死的解剖学基础。方法:在40侧经动脉内灌注红色乳胶标本,解剖观察梨状肌上孔、臀上血管神经走行及分支分布,髂内动脉造影观察吻合情况。结果:梨状肌上孔为半圆形,中点高(11.6±2,4)mm,下界宽(22.3±4.2)mm;梨状肌上孔内侧缘骨壁厚(7.5±1.2)mm;臀上动脉外径厚(2.3±1.3、)mm;外径宽(4.8±1.0)mm;臀上动脉深支分布臀中小肌;浅支外径厚(0.9 0.6)mm;外径宽(2.7±0.8)mm,分布臀大肌内侧上部。臀上静脉1支型占30.0％,2支型占70.0％;臀上静脉浅支外径厚(0.6±0.2)mm,外径宽(0.9±0.6)mm。结论:术中将臀大肌向内推臀上动、静脉挤压至梨状肌上孔内侧缘骨壁上,致臀上血管断裂,并发臀内侧上部软组织坏死。     

臀上动脉深上支髂骨骺移植的解剖学研究

目的 :为带血供的髂骨骺移植提供解剖学依据。方法 :在 40侧经动脉灌注红色乳胶的成人臀部标本以及 2侧儿童标本上 ,观测臀上动脉深上支的行程、分支及滋养支 ;选用 5 0块髋骨 ,观察髂骨嵴前外侧部的滋养孔。结果 :儿童臀上动脉深上支的分支、分布与成人相似 ,位于臀中肌深面和臀小肌上缘 (相当臀前线 ) ,循髂骨嵴弓形向前 ,达髂前上嵴 ,沿途分出平均 (4 .2± 1.1)支外径 0 .5～ 1.1mm的髂嵴支 ,分布髂嵴骨膜 ,并发细小分支进入滋养孔。从髂前上棘至结节区 ,在距髂嵴缘下方 2cm范围内 ,平均有(2 2 .4± 6.7)个滋养孔。结论 :以臀上动脉深上支及其分支为蒂 ,在髂嵴前部可切取带骺骨瓣 ,以修复长管骨骨骺缺损。     

腹壁下动脉穿支皮瓣及腹壁浅动脉皮瓣的血供解剖研究

目的　针对下腹部皮瓣及皮下组织的血供分区尚存在争议,对血供分区、血管及其相互间的吻合情况进行综合分析,为穿支皮瓣的应用提供解剖学基础。 方法　使用改良的一次性全身动脉造影技术,灌注10具新鲜尸体标本。经螺旋CT扫描后,应用交互式医学影像控制系统（Mimics）对腹壁下动脉及其穿支和腹壁浅动脉进行3D可视化研究,并对下腹壁区域皮肤及皮下组织等进行层次解剖与X线摄像。 结果　腹壁下动脉有3种分支形式,当其分为2支或3支时,发出相对应的内、外两排穿支。腹壁浅动脉的解剖变异度较大,但均与腹壁下动脉穿支间有丰富的吻合。 结论　腹壁血供传统分区的争议与术中选择内排或外排穿支有关。当术前确认腹壁浅动脉管径较大,且所需组织量不超过半腹部时,腹壁浅动脉皮瓣是一种很好的术式选择。     

The ramification of the superficial branch of the superior gluteal artery. Anatomical basis of a new gluteus maximus myocutaneous flap

Summary In order to design a new gluteus maximus myocutaneous flap, the ramification of the superficial branch of the superior gluteal artery was investigated in 56 sides of 33 Japanese cadavers. The superficial branch constantly divides into two main branches, which are called the ascending and transverse branches in this study. Of the ascending and transverse branches, one or both usually give off at least one well developed division running on the undersurface of the gluteus maximus muscle (98.2%). This division, which is called the intermediate branch in this study, generally reaches the superior edge of the muscle giving off only a couple of muscular branches and pierces the muscle and its deep fascia to supply skin (83.6%). Perforators of the intermediate branch constantly emerge from the fascia near the middle or lower one-third point on a line extending from the middle of the iliac crest to the tip of the greater trochanter.

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Les ramifications de la branche superficielle de l'artère gluteale supérieure. Bases anatomiques d'un nouveau lambeau myocutane de muscle grand fessier

Résumé Dans le but de créer un nouveau lambeau myocutané de muscle grand fessier, les ramifications de la branche superficielle de l'artère glutéale supérieure ont été étudiées chez 33 sujets japonais (56 cotés). La branche superficielle se divise de façon constante en deux rameaux principaux, qui seront appelés dans cette étude les branches ascendante et transverse. De l'une de ces deux branches, ou parfois des deux, naît souvent au moins un rameau bien développé courant sous le muscle grand fessier (98,2%). Cette branche de division, qui est nommée dans cette étude le rameau intermédiaire, atteint généralement la limite supérieure du muscle, en abandonnant seulement quelques rameaux musculaires, et perfore le muscle et son fascia profond pour vasculariser la peau (83,6%). Les branches perforantes du rameau intermédiaire traversent le fascia, de façon constante, au niveau du milieu ou du tiers inférieur d'une ligne tendue du milieu de la crête iliaque au sommet du grand trochanter.