Descriptive anatomy of the femoral portion of the iliopsoas muscle. Anatomical basis of anterior snapping of the hip

Abstract: Anterior hip snapping is a rare clinical observation. The physiopathological hypothesis currently held is a sudden slip of the iliopsoas tendon over the iliopectineal eminence. For symptomatic cases, a surgical technique is proposed. The aim of this work is to describe the anatomy of the femoral portion of the iliopsoas, which is the target of surgery. We have studied, through dissection of embalmed cadavers, the different components of the musculotendinous complex forming the femoral portion of the muscle and the gliding apparatus associated with it. The psoas major tendon exhibited a characteristic rotation. The iliacus tendon, more lateral, received the most medial iliacus muscular fibers, then fused with the main tendon. The most lateral fibers, starting in particular from the ventral portion of the iliac crest, ended up without any tendon on the anterior surface of the lesser trochanter and in the infratrochanteric region. The most inferior muscular fibers of the iliacus, starting from the arcuate line, joined the principal tendon of the psoas major passing around it by its ventromedial surface. An ilio-infratrochanteric muscular bundle was observed, in a deeper position, under the iliopsoas tendon; it arose from the interspinous incisure and on the anterior inferior iliac spine, ran along the anterolateral edge of the iliacus and inserted without any tendon onto the anterior surface of the lesser trochanter of the femur and in the infratrochanteric area. The iliopectineal bursa was studied on horizontal cross sections of a frozen pelvis and on 5 of the non-frozen preparations after dividing the iliopsoas tendon. The iliopectineal bursa had the shape of a 5 to 6-cm high and 3-cm wide cavity; in its upper part, it was divided into 2 compartments a medial compartment for the main tendon and a lateral compartment for the accessory tendon.     

Revision of hip flexor anatomy and function in modern humans,and implications for the evolution of hominin bipedalism

Hip flexor musculature was instrumental in the evolution of hominin bipedal gait and in endurance running for hunting in the genus Homo. The iliacus and psoas major muscles were historically considered to have separate tendons with different insertions on the lesser trochanter. However, in the early 20th century, it became “common knowledge” that the two muscles insert together on the lesser trochanter as the “iliopsoas” tendon. We revisited the findings of early anatomists and tested the more recent paradigm of a common “iliopsoas” tendon based on dissections of hips and their associated musculature (n = 17). We rediscovered that the tendon of the psoas muscle inserts only into a crest running from the superior to anterior aspect of the lesser trochanter, separate from the iliacus. The iliacus inserts fleshly into the anterior portion of the lesser trochanter and into an inferior crest extending from it. We developed 3D multibody dynamics biomechanical models for: (a) the conjoint “iliopsoas” tendon hypothesis and (b) the separate insertion hypothesis. We show that the conjoint model underestimates the iliacus' capacity to generate hip flexion relative to the separate insertion model. Further work reevaluating the primate lower limb (including human) through dissection, needs to be performed to develop those datasets for reconstructing anatomy in fossil hominins using the extant phylogenetic bracket approach, which is frequently used for tetrapods clades outside of paleoanthropology.     

Bursa iliopectinea--size and morphology

The size of the iliopsoas bursa is usually larger than its size described in textbooks of anatomy. Proximally the synovial bursa lies on the pectineal eminence of the superior pubic ramus, passes across the front of the capsule of the hip joint and extends distally downwards almost as far as to the lesser trochanter. Only the tendon of the psoas major muscle is normally an immediate relation to the bursa. In 13% of all cases the iliopsoas bursa is partly separated by a septum into 2 cavities. Here the tendon of the psoas major muscle passes over the medial chamber and the tendon of the iliac muscle runs over the lateral chamber. With regard to modern diagnostic techniques (computer tomography, magnetic resonance-tomography) the results are significant for the differential diagnosis of inflammatory processes in hip joints.     

Variant slips of psoas and iliacus muscles,with splitting of the femoral nerve

In bilateral dissections of 68 cadavers, four examples were found unilaterally of variant slips of iliacus and psoas major muscles. In three of them the femoral nerve was pierced by the variant slip. One of these variants was a previously undocumented accessory slip of iliacus, originating from the iliolumbar ligament, passing inferiorly anterior to iliacus, and traversing the femoral nerve; its tendon split to be attached proximally to the lesser trochanter of the femur and distally to an unknown insertion. Such anomalies might cause tension on the femoral nerve resulting in referred pain to the hip and knee joints and to the lumbar dermatomes L2,3 and 4. © 1996 Wiley-Liss, Inc.     

Segmental fibre type composition of the rat iliopsoas muscle

The iliopsoas of the rat is composed of two muscles – the psoas major muscle and the iliacus muscle. The psoas major muscle arises from all the lumbar vertebrae and the iliacus muscle from the fifth and sixth lumbar vertebrae and ilium. Their common insertion point is the lesser trochanter of the femur, and their common action is the lateral rotation of the femur and flexion of the hip joint. Unlike humans, the rat is a quadruped and only occasionally rises up on its hind legs. Therefore, it is expected that the fibre type composition of the rat iliopsoas muscle will be different than that of humans. The iliopsoas muscle of the rat is generally considered to be a fast muscle. However, previous studies of the fibre type composition of the rat psoas muscle showed different results. Moreover, very little is known about the composition of the rat iliacus muscle. The aim of our study was to examine the fibre type composition of the rat iliopsoas muscle in order to better understand the complex function of the listed muscle. The psoas major muscle was examined segmentally at four different levels of its origin. Type I, IIA, IIB and IIX muscle fibres were typed using monoclonal antibodies for myosin heavy chain identification. The percentage of muscle fibre types and muscle fibre cross‐sectional areas were calculated. In our study we showed that in the rat iliopsoas muscle both the iliacus and the psoas major muscles had a predominance of fast muscle fibre types, with the highest percentage of the fastest IIB muscle fibres. Also, the IIB muscle fibres showed the largest cross‐sectional area (CSA) in both muscles. As well, the psoas major muscle showed segmental differences of fibre type composition. Our results showed changes in percentages, as well as the CSAs of muscle fibre types in cranio‐caudal direction. The most significant changes were visible in type IIB muscle fibres, where there was a decrease of percentages and the CSAs from the cranial towards the caudal part of the muscle. From our results it is evident that the rat iliopsoas muscle has a heterogeneous composition and is composed of all four muscle fibre types. Primarily, it is a fast, dynamic muscle with a predominance of fast type IIB muscle fibres with the largest CSAs. The composition of the rat psoas major muscles changes in a cranio‐caudal direction, thus pointing to a more postural role of the caudal part of the muscle.     

Femoral nerve entrapment: a new insight

Compression of the femoral nerve in the iliac fossa has been reported as a consequence of several pathologies, but never as a result of muscular compression. Aberrant slips of iliacus, however, have occasionally been reported to cover or split the femoral nerve. This study aimed to assess such variations as potential factors in femoral nerve compression. A large and homogeneous sample of 121 embalmed cadavers (242 specimens) was studied. Statistical comparisons were made using the chi-squared test. Muscular slips from iliacus and psoas, piercing or covering the femoral nerve, were found in 19 specimens (7.9%). No significant differences by sex or side were found. The more frequent variation was piercing of the femoral nerve by a muscular slip (17 specimens, 7.0%). The nerve then entered the thigh as one or more branches. The less frequent variation found was a muscular slip or sheet covering the femoral nerve as it lay on iliacus (2 specimens, 0.8%). Each disposition may be a potential risk for nerve entrapment.     

以髂腰血管为蒂髂骨（膜）瓣移植的应用解剖

目的：为髂腰血管蒂髂骨（膜）瓣移植提供解剖学基础。方法：在２７具灌注红色乳胶的成尸标本上，对髂腰血管的起始、走行及分支分布进行解剖观测，并在标本上摹拟骨瓣切取。结果：髂腰动脉９６．３％起自髂内动脉，３．７％起自髂总动脉。其主干７９．６％走行髂肌浅面，２０．４％走行于髂肌深面，末端均分布髂嵴中部，并与前、后血管之间形成吻合。髂腰动脉起始处外径为２．７ｍｍ，腰大肌外侧缘处外径为１．６ｍｍ。由腰大肌外侧缘至其末端的长度为４．５ｃｍ，分布于髂嵴中部的范围长为７．０ｃｍ左右。结论：以髂腰血管为蒂可切取髂嵴中部骨瓣移植     

Examination of the variations of lateral femoral cutaneous nerves: report of two cases

The origins, courses and relations of lateral femoral cutaneous nerves (LFCNs) were examined bilaterally in 28 cadavers, and the variations were observed in two. On the right side of one cadaver, the ventral rami of the first and second lumbar spinal nerves were united and then this nerve was divided into four branches. From medial to lateral, these branches were the obturator nerve, the femoral nerve, the medially located LFCN and the laterally located LFCN. On the left side of another cadaver, there were three LFCNs. All of these nerves pierced the psoas major muscle anterolaterally. Two of these nerves, which pierced the psoas major muscle more proximally than the third, united with each other by a communicating branch anterior to the iliacus muscle. These types of variations are very important, especially in the presence of paresthesias or pain in the anterior thigh, lateral thigh and gluteal region. In these cases, surgeons must always remember the possible variations of the LFCN during surgical procedures in order to prevent injury and the occurrence of meralgia paresthetica.     

带血管肋间神经与髂腰肌支吻接重建屈髋功能应用解剖

目的：为带血管的肋间神经与髂腰肌支吻接重建屈髋功能提供解剖学基础。方法：在30侧成人标本上对支配髂肌、腰大肌的神经进行解剖和观察。结果：支配腰大肌的神经纤维主要来源于L2，其次是L3肌支纤维在L2神经干的外上部走行，部位较恒定。髂肌肌支则在股神经合于起始处发出，神经纤维主要来源于L4，其次为L3及L2。结论：将肋间神经转位从背侧手术入路与L2神经根前支外上部端侧吻接，或经腹手术入路于股神经起始部与髂肌肌支吻接术式具有可行性。     

New insight into the iliofemoral ligament based on the anatomical study of the hip joint capsule

The iliofemoral ligament, which plays an important role in hip joint stability, is formed on the anterosuperior region of the hip joint capsule. Although the tendon and deep aponeurosis of the gluteus minimus and iliopsoas are partly connected to the same region of the capsule, the precise location of the connections between the joint capsule and the tendons and deep aponeuroses remains unclear. The locations of the tendinous and aponeurotic connections with the joint capsule may clarify whether the iliofemoral ligament can be regarded as the dynamic stabilizer. This study investigated the relationships between the anterosuperior region of the joint capsule and the tendon and deep aponeurosis of the gluteus minimus and iliopsoas. Fourteen hips from nine cadavers (five males; four females; mean age at death 76.7 years) were analyzed. Ten hips were macroscopically analyzed, and four were histologically analyzed. During macroscopic analysis, the joint capsule was detached from the acetabular margin and the femur, and its local thickness was measured using microcomputed tomography (micro-CT). The gluteus minimus tendon was connected to the joint capsule, and the lateral end of this connection was adjoined with the tubercle of the femur at the superolateral end of the intertrochanteric line. The deep aponeurosis of the iliopsoas was also connected to the joint capsule, and the inferomedial end of its anterior border corresponded with the inferomedial end of the intertrochanteric line. In the micro-CT analysis, capsular thickening was observed at the base of the connection to the gluteus minimus tendon and at the anterior border of the deep aponeurosis of the iliopsoas. A histological study showed that the gluteus minimus tendon and the deep aponeurosis of the iliopsoas were continuous with the hip joint capsule. Based on the morphology of the tendinous and aponeurotic connections, local capsular thickening and histological continuity, the transverse and descending parts of the iliofemoral ligament were the joint capsules, with fibers arranged according to the connection with the gluteus minimus tendon and the deep aponeurosis of the iliopsoas, respectively. Therefore, the so-called iliofemoral ligament could be regarded as the dynamic stabilizer, with the ability to transmit the muscular power to the joint via the capsular complex. This anatomical knowledge provides a better understanding of the hip stabilization mechanism.     

根据肌内神经分布定位髂腰肌和腰方肌痉挛的阻滞靶点

目的　通过探索髂腰肌和腰方肌的肌内神经分布模式,定位其肌痉挛时肉毒毒素A的阻滞靶点。 方法　12具24侧中国成人尸体髂腰肌和腰方肌。改良的Sihler’s染色法显示肌内神经分布。 结果　髂腰肌和腰方肌的神经支配源于T12和L1～L4脊神经分支。腰大肌肌腹上1/2区内有一神经分支密集区,位于肌长的（12.10±0.65）%～（43.20±1.17）%水平,其中心点在肌长（23.90±0.82）%水平,向内平对第三腰椎体中部;髂肌中央有一与髂嵴平行的蚕豆形神经密集区,其中心点位于髂腰肌肌长的（58.0±1.61）%水平,向外平对髂结节;腰方肌的内上和下1/3部各存在1个肌内神经密集区,其中心点分别平对第一和第三腰椎体下部。 结论　这些肌内神经密集区及中心的定位研究能指导临床医生注射肉毒毒素A接近其作用部位。     

非透视下确定顺行股骨髓内钉大转子进钉点的解剖观察及临床应用

目的 探讨非透视下确定顺行股骨髓内钉大转子进钉点的技术方法。方法 2007年12月—2008年6月选取10%甲醛溶液固定的成人髋部湿标本8具,男5例、女3例,观察股骨大转子解剖特征,标记大转子上臀中肌、梨状肌的附着情况,观察股骨大转子嵴拐点凹陷、髓腔中轴线与梨状窝的解剖关系。2010年1月—2012年12月对收治的44例股骨转子间及股骨干骨折患者进行前瞻性研究。其中男20例,女24例;年龄25～85岁,平均 (66.9± 15.7)岁。患者均行顺行髓内钉固定术,术中根据标本解剖中发现大转子嵴拐点凹陷和梨状窝的关系,非透视下通过手法触摸确定髓内钉开口位置。结果 尸体标本解剖研究发现,股骨大转子在与股骨颈结合部形成一个向外侧凸出类似“C”形的山嵴样结构。股骨大转子嵴呈后方高、前方平坦下降似斜坡样结构,中间凭借手指就可以感觉有一个类似拐点的凹陷切迹。臀中肌附着在大转子嵴的外侧部分,梨状肌腱附着在大转子嵴拐点切迹的内侧部分。梨状窝就是梨状肌附着点的骨质凹陷,梨状窝基本位于髓腔中轴线上、大转子嵴拐点凹陷的内侧。44例患者中,1例患者术中无法满意确定骨折近端髓腔朝向,开口过程中采用X线透视检查髓腔开口器的方向;43例均在非透视的情况下将髓内钉导针置入髓腔,髓内钉均置入良好。术后随访时间9～28个月,平均18.4个月;除1例股骨干骨折愈合迟缓,动力化后愈合外,其他患者均愈合良好;随访期间所有患者无髓内钉松动、股骨头切出等并发症。结论 在股骨干和股骨转子区骨折采用顺行髓内钉固定治疗术中,非透视下通过手法触摸,可以利用大转子嵴拐点凹陷切迹代替梨状窝参考定位,确定髓内钉开口位置,避免反复透视,降低辐射损害。     

Relationship between the hip joint capsule and piriformis tendon in a simulation of the modified Watson‐Jones anterolateral approach in THA cadaver study

Fifteen fresh frozen cadavers were used for a simulation of the modified Watson‐Jones anterolateral approach in an anatomical study. Several parameters were measured to evaluate the relation between the piriformis tendon insertion and hip joint capsule insertion. The anteroposterior diameter of the piriformis tendon was found to be greater than the medial–lateral diameter, and that the posterior part of the incised hip joint capsule is distant from the piriformis tendon as the piriformis is inserted into the extra‐articular portion. We also found that it was important not to dissect the anteroproximal portion of the greater trochanter to prevent rupture of the piriformis tendon, whereas the posterior portion was relatively safe. Clin. Anat. 26:610–613, 2013. © 2012 Wiley Periodicals, Inc.     

背阔肌腱下滑囊炎的应用解剖研究

目的    为临床诊治背阔肌腱下滑囊炎提供应用解剖学基础。  方法　20侧成人肩关节标本（右11侧、左9侧），对背阔肌腱下滑囊及与其邻近易误诊的解剖结构进行观测。  结果　背阔肌腱下滑囊位于肱骨结节嵴间沟底、肱骨小结节嵴、大圆肌附着部与背阔肌腱止点之间。肱骨结节间沟可分为肱骨大、小结节间沟和大、小结节嵴间沟，确定该滑囊的上下位置，即从肱骨小结节最高点至背阔肌腱下滑囊上端距离为（27.43±4.71）mm，可以确定该滑囊的上下位置，背阔肌腱下滑囊的内外位置关系，从肱二头肌长头腱内侧缘距背阔肌腱下滑囊中点为（8.12±1.23）mm，可以确定该滑囊的内外位置关系。背阔肌腱下滑囊的相关数据，在肱骨结节嵴间沟上、下高度为（36.5±4.79）mm，中点宽度为（8.62±1.83）mm。背阔肌腱下滑囊周围易发生炎症的有肱二头肌长头腱滑液鞘、大圆肌腱下滑囊、喙突下滑囊、胸大肌骨管等。  结论　本研究为背阔肌腱下滑囊的诊疗提供了形态学依据。     

髂腹股沟下入路中间窗解剖及改良

目的 为髋臼骨折髂腹股沟下入路血管损伤、术后血栓及淋巴漏的预防提供解剖学依据。 方法 20具（男女各10具,40侧）国人尸体标本,参照临床手术步骤解剖,观察和测量与髂腹股沟下入路中间窗显露相关结构的特点及关系。 结果 腹壁下动脉23侧（57.5%）起自髂外动脉,7侧（17.5%）起自股动脉,起点距耻骨联合中点(41.35±2.33)mm,与髂外动脉夹角约(40.23±5.23)°,左右侧差异无统计学意义（P＞0.05）,且与骨盆纵径及半骨盆横径不相关（P＞0.05）。髂血管周围无明确筋膜鞘样结构,血管和淋巴易受到牵拉损伤;股血管有明显鞘样结构,但与周围结构连接疏松易分离。髂耻弓起始处与腹股沟韧带内侧半呈(15.20±6.79)°锐性夹角,有少量菲薄膜样结构,易分离。髂筋膜内下部较厚,且厚度与骨盆纵径及半骨盆横径不相关（P＞0.05）。结论 髂腹股沟入路和髂腹股沟下入路中间窗显露时均易伤及血管和淋巴管,髂筋膜下部和髂耻弓结构致密,可从髂筋膜下分离与内侧窗贯通。     

Defining the position of deep inguinal ring in patients with indirect inguinal hernias

A preliminary survey of surgeons of all grades in our hospital revealed confusion about the position of the deep inguinal ring. Standard teaching is that the deep inguinal ring is lateral to the femoral artery. The aim of this study was to define the position of the deep ring in patients undergoing elective inguinal hernia repair. Thirty consecutive male patients undergoing indirect inguinal hernia repair under local anaesthesia were studied. The following landmarks were marked on the patient with a felt pen: anterior superior iliac spine (ASIS), femoral artery (FA), deep inguinal ring (DR), pubic tubercle (PT) and pubic symphysis (PS). The distance of each point from the ASIS was measured in centimetres. The relation of the femoral artery to the deep inguinal ring was confirmed by palpation through the deep ring during surgery. The femoral artery was consistently identified midway between the anterior superior iliac spine and pubic symphysis (mid-inguinal point). The deep inguinal ring was located medial (22/30) or above (8/30) the femoral artery, but never lateral. The mean distances from the anterior superior iliac spine to the deep ring and femoral artery were 8.8 and 7.7 cm, respectively. Contrary to standard teaching, this study demonstrates that the deep inguinal ring lies medial, not lateral, to the femoral artery. This may clarify some of the variations in textbook anatomy, and explain the difficulty in distinguishing direct and indirect inguinal hernias pre-operatively.Presented at the Association of Surgeons of Great Britain and Ireland (ASGBI, April 2004 Harrogate)     

On the organization of the Plexus lumbalis. I. On the recognition of the three-layered divisions and the systematic description of the branches of the human femoral nerve.

The arrangement of the nerve bundles at the branching point of the femoral nerve (F), the interrelations of the branches each other and toward other nerves in the anterior region of the thigh, and the patterns and the anatomical features of both the running courses and the distributions of the branches were macroscopically studied, whereby some special findings were observed and the following results were obtained: 1) The periphery of the femoral nerve was fundamentally divided into superficial-deeply arranged three-layered divisions. Including the femoral branch of the genitofemoral nerve (Rf) and the femoral lateral cutaneous nerve (Cfl), the nerve branches at the anterior region of the thigh were totally divided into five-layered divisions. 2) The cutaneous branches of each division including Rf or Cfl could be classified in three groups: the medial cutaneous branches (m), the anterior cutaneous branches (a), and the lateral cutaneous branches (l). Based on the above results, the branches could be described systematically. Parallelly, several accessory bundles of F penetrating the psoas major muscle were observed, and two types of accessory femoral nerves (F') could be distinguished: One was higher on the segmentation and mainly flew into the 1st division of F. While the other distributed only to the medial region of the thigh. To clarify the segmental or stratifical natures of the branches of each division, F', and the interrelations among them, analyses of the nerve fibers were undertaken under the operational microscope. Consequently, the segmental differences between the divisions were distinct, and the medial branches or F'm obviously contained ventral components. Thus, when a component originated from the higher segments, it distributed to the proximal region generally taking a superficial course; when it originated from the lower ones, it distributed to the distal region of the thigh forming the deeper division; when it belonged to the ventral stratum, it distributed to the medial region; and when it belonged to the dorsal stratum, it distributed to the lateral region. On the occasion of the fiber analysis, it was found that each root of the lumbar nerve was generally divided into two or three subsegmentally-arranged subroots that divided themselves into some fasciculi arranged micro-segmentally. A minute analysis of the segmentations of the nerves became possible because of the above characteristics.     

INFIX置钉入路的改良研究及其在骨盆骨折治疗中的应用

目的　探讨将INFIX置钉入路内移至缝匠肌与髂腰肌间隙的可行性,并评估其临床疗效和并发症。 方法　在大体标本上测量缝匠肌内、外缘至股外侧皮神经和股神经的距离,用t检验比较各组间的差异性。收集南方医科大学珠江医院从2016年8月~2018年12月应用INFIX技术治疗的骨盆骨折14例,从骨盆畸形指数、耻骨联合宽度、术后负重时间、内固定取出时间及Majeed评分等方面评估临床疗效,分析有无股外侧皮神经损伤、股神经损伤等并发症。 结果　缝匠肌内缘比外缘至股外侧皮神经的距离增加了7.71mm（P<0.01）,而至股神经的距离仍有22.36 mm。INFIX术后骨盆畸形指数减少了1.82%（P<0.01）,耻骨联合宽度缩小了6.98 mm（P<0.05）,平均12.70周负重,29.50周取出内固定,Majeed评分90.80分。术后无股外侧皮神经和股神经损伤,2例出现切口感染,1例有主观不适感。 结论 　INFIX置钉入路内移至缝匠肌与髂腰肌间隙可减少股外侧皮神经的损伤风险,且不干扰股神经,对于骨盆前环骨折具有微创、疗效好、并发症少等优势。