Proposal for classification of the suprascapular notch: a study on 423 dried scapulas

The present study proposes a simple and reproducible method to classify the morphology of the suprascapular notch (SSN), on the basis of specific geometrical parameters that clearly distinguish one type from another. Four hundred twenty-three dried scapulas from the Department of Anatomy in the University of Cologne, Germany, were examined. Five types of SSN were observed: type I, without a discrete notch, 35 (8.3%); type II, a notch that was longest in its transverse diameter, 177 (41.85%); type III, a notch that was longest in its vertical diameter, 177 (41.85%); type IV, a bony foramen, 31 (7.3%); type V, a notch and a bony foramen, 3 (0.7%). For the vertical diameter, we took the maximal diameter of the notch perpendicular to the imaginary line that joins the two superior corners of the notch. For the transverse diameter, we took the diameter perpendicular to the midpoint of the vertical diameter. This classification based on the vertical and the transverse diameters of the SSN suggested a clear distinction of the notch types. This simple classification included all the anatomical variations of the SSN. Using this method, the clinician will be able to define easily and quickly the notch type on a plain radiograph, and perhaps be able to correlate suprascapular nerve entrapment with a specific type of SSN.     

Sexual dimorphism of the suprascapular notch – morphometric study

Introduction

The concept of the study was to compare the morphometry of the suprascapular notch (SSN) in females and males because its size and shape may be a factor in suprascapular nerve entrapment.

Material and methods

The measurements of 81 scapulae included morphological length and width, maximal width and length projection of the scapular spine, and width and length of the glenoid cavity. The width-length scapular and glenoid cavity indices were calculated. In addition to standard anthropometric measurements three other dimensions were defined and collected for every SSN: maximal depth (MD), superior (STD) and middle (MTD) transverse diameters.

Results

The analysis of the measurements allowed us to distinguish five types of SSN. Type I (26%) had longer maximal depth than superior transverse diameter. Type II (3%) had equal MD, STD and MTD. In type III (57.6%) superior transverse diameter was longer than maximal depth. In type IV (7.4%) a bony foramen was present. Type V (6%) was without a discrete notch. Types I and III were divided into two subtypes: A (MTD was longer than STD) and B (MTD < STD). Distribution of the suprascapular notch types in both sexes was similar. However, MD, STD and MTD were significantly higher in males. The superior transverse suprascapular ligament was completely and partially ossified in 7.4% and 24.7% respectively.

Conclusions

The presented classification of the suprascapular notch is simple, easy to use, and based on specific geometric parameters which allow one to clearly distinguish five types of these structures. All dimensions of SSN were significantly higher in males than in females.     

Clinical evaluation of the shape of the suprascapular notch—an ultrasonographic and computed tomography comparative study: Application to shoulder pain syndromes

The most common site of suprascapular nerve compression and injury is the suprascapular notch. The aim of this study was to assess the sensitivity and specificity of sonography in determining the type of suprascapular notch (SSN). Thirty randomized patients (60 upper extremities) underwent USG examination of the shoulder area. The results were further compared with three‐dimensional reconstructions of the scapulae obtained through CT examination to place the SSNs within a fivefold classification. For identification of type I, the sensitivity was 73.3% and the specificity 97.8%. For identification of type III, the values was 96.9% and 85.7%, respectively. Type II was not found in USG examination. Discrimination between type IV and V was not possible. The mean distance between the line connecting the edges of the SSN and the skin was 38 mm in right‐handed patients and 34 mm in ambidextrous subjects. Ultrasonographic examination of the SSN is characterized by high specificity for type I, and high sensitivity for type III SSN. Discrimination between type IV and V of the SSN is not recommended based on sonographic evaluation. Clin. Anat. 28:774–779, 2015. © 2015 Wiley Periodicals, Inc.     

Topographical anatomy of the suprascapular nerve and vessels at the suprascapular notch

Suprascapular nerve entrapment caused by the superior transverse scapular ligament (STSL) causes pain, and limitation of motion in the shoulder. To relieve these symptoms, suprascapular nerve decompression is performed through the resection of STSL. To describe and classify the topographic anatomy of the suprascapular notch, 103 cadaveric shoulders were dissected. The mean length and width of STSLs were 11.2 and 3.4 mm, respectively. The bony bridges replacing STSL in four shoulders were 8.2 mm long and 3.5 mm wide on average. The suprascapular nerve always ran through the notch under the STSL. All shoulders had a single suprascapular artery, while multiple suprascapular veins appeared in 21.3%. The arrangement of the suprascapular vessels was classified into three types: in Type I (59.4%), all suprascapular vessels ran over the STSL; in Type II (29.7%), the vessels ran over and under the STSL simultaneously; in Type III (10.9%), all vessels ran under the STSL. In 48.9% of cadavers, these types were bilaterally matched. The omohyoid muscle originated distantly from the STSL in 38.0%, was adjacent to it in 44.0%, and was partially over the STSL in 18.0%. The number of suprascapular vessels running under the STSL was positively correlated with the size of the STSL and the middle diameter of the suprascapular notch. Age was inversely correlated with the length of STSL. The STSL was wider in males than in females. This study provides details of the structural variations in the region of the suprascapular notch.     

针刀微创手术治疗肩胛上神经卡压的解剖学研究

目的观测肩胛上横韧带,肩胛上动脉、肩胛上神经及其冈上肌支,为针刀治疗肩胛上神经卡压提供解剖学依据。方法解剖观测肩胛上横韧带的长度、宽度和厚度;观察肩胛上动脉和肩胛上神经以及它们的冈上肌支与肩胛上横韧带的位置关系,测量它们在肩胛切迹处的直径;以韧带内侧附着处下点的骨面为基点,确定体表穿刺点和穿刺深度。结果肩胛上横韧带下缘长(0.901±0.234)cm,韧带中间窄厚,内、外侧附着点宽薄;肩胛上神经走行于肩胛切迹内,肩胛上横韧带的下方;肩胛上动脉有16.67%走行于切迹内神经的外侧,83.33%走行在切迹外韧带外上方;肩胛上神经的冈上肌支经肩胛切迹内上角走行入冈上肌;体表穿刺定位角为(24.102±3.681)°。穿刺定位距离计算的回归方程是:Y=2.560+0.615X,穿刺深度为(4.342±0.629)cm。结论针刀切断韧带的方向应从韧带内侧部下缘切向内上,可避免损伤韧带下方的肩胛上神经和韧带外上的肩胛上动脉,且可更有效地解除对肩胛上神经及其冈上肌支的卡压;直线回归方程使穿刺的体表定位因人而异,更为准确。     

Anatomical basis of the suprascapular nerve entrapment, and clinical relevance of the supraspinatus fascia

Introduction  

The entrapment of the suprascapular nerve (SSN) is commonly considered at the level of the suprascapular notch and more rarely in the spinoglenoid notch. Recent per-operative findings showed a compression of the SSN along its course in the supraspinatus fossa. The removal of a fascia for releasing the nerve between the suprascapular notch and spinoglenoid notch led us to purchase an anatomical study.     

基于CT三维重建的肩胛切迹解剖分型及临床意义

目的 探讨基于CT三维重建的肩胛切迹解剖形态学分型及临床意义。 方法 收集来自西南医科大学附属中医医院300例因肩部疾病就诊患者的肩胛骨,通过CT三维技术重建肩胛骨图像,并进行肩胛切迹形态学分型及几何数据测量。 结果 我们将收集的肩胛切迹分为5种类型,√-形称为Ⅰ型共138例,约占46%;U-形称为Ⅱ型共125例约占41.7%;Ⅴ-形称为Ⅲ型,共20例,约占6.7%;O-形称为Ⅳ型,共10例约占3.3%;Ω-形称为Ⅴ型,共7例约占2.3%（另外,发现W-形、双O-形各1例,因数量较少暂未纳入分型）;左侧肩胛切迹平均深度、宽度分别为（5.58±1.42、10.22±3.24）mm,右侧肩胛切迹平均深度、宽度分别为（6.02±1.87、10.81±3.35）mm,左右对比差异有统计学意义（P<0.05）;Ⅰ和Ⅱ型的切迹宽度较其他3种类型宽度更宽,分别为（12.46±3.20、9.95±2.68）mm,且P<0.05差异有统计学意义;另外,不同类型中肩胛切迹最低点到肩胛冈基底部的垂直距离长度有所不同,其中Ⅰ型最短的为（12.52±2.56）mm,Ⅲ型最长的为（14.48±4.29）mm,Ⅰ型和Ⅲ型比较差异有统计学意义（P<0.05）。 结论 基于CT三维重建结果,将肩胛切迹分为5型,分别为√-形、U-形、Ⅴ-形、O-形、Ω-形。其中Ⅴ-形和O-形发生肩胛上神经卡压症的几率较大,而√-形及U-形的卡压几率则较小。     

Coexistence of the suprascapular notch and the suprascapular foramen—a rare anatomical variation and a new hypothesis on its formation based on anatomical and radiological studies

The suprascapular notch is the most common site of suprascapular nerve entrapment, which can manifest in disability and pain of the upper limb. Here, we present three cases of a very rare anatomical variation in the suprascapular region: the coexistence of the suprascapular notch and the suprascapular foramen. The variation was found during radiological and anatomical investigations. The suprascapular foramen was situated inferior to the suprascapular notch. A bony bridge lay between them, likely created by an ossified anterior coracoscapular ligament (ACSL). This anatomical variation probably increased the risk of suprascapular nerve entrapment by nerve irritation of the bony margins during passsage through the foramen and by a lack of the elasticity that the ACSL normally demonstrates. Also, a bony bridge passing through the middle part of the suprascapular notch reduces the space available for nerve passage (bony bridge decreases the space by about 36.5–38.6 %). One patient who underwent the radiological study had typical symptoms of suprascapular nerve entrapment. Based on his medical history and the presence of this rare variation of the suprascapular notch at the suprascapular region we suspect this neuropathy.     

Proposed surgical technique to facilitate targeted reinnervation of the infraspinatus: A cadaveric feasibility study

Restoration of shoulder lateral rotation remains a significant challenge following brachial plexus injury. Transfer of the accessory nerve to suprascapular nerve (SSN) has been widely performed, although with generally poor outcomes for lateral rotation. A recent report suggested a selective infraspinatus reinnervation technique using a radial nerve branch for SSN transfer. This cadaveric study was performed in 7 specimens (14 shoulders). We present technical modifications to achieve additional length to the recipient nerve (suprascapular) that would facilitate direct repair. Key elements of the technique are (1) isolation of the SSN immediately distal to its motor branch to supraspinatus near the superior transverse scapular ligament; and (2) delivery of the transected SSN through the spinoglenoid notch and deep to the infraspinatus for emergence in the infraspinatus‐teres minor interval. Nerve overlap of at least 21 mm was observed in all 14 dissected shoulders between the harvested SSN and radial nerve branches. The mean nerve overlap between harvested branches was 26 mm (range 21–32 mm). The mean harvested SSN length was 59 mm (range 46–80 mm). The mean length of the harvested radial nerve branch was 72 mm (range 65–85 mm). No measurements were significantly different between left and right shoulders or between males and females (smallest P value = 0.1249). Nerve diameter of the two harvested branches was judged to be appropriately compatible for surgical coaptation in all 14 dissected shoulders. We present a variation on a described technique to increase recipient suprascapular nerve length. Additional length of the recipient nerve is achieved through utilization of a more proximal dissection of the suprascapular nerve near the level of the superior transverse scapular ligament and delivering the nerve through the teres minor‐infraspinatus interval. These surgical modifications are of clinical interest when selective reinnervation of the infraspinatus muscle is considered. We believe such a targeted approach can potentially increase shoulder lateral rotation function. Clin. Anat. 32:131–136, 2019. © 2018 Wiley Periodicals, Inc.     

Morphometric study of the suprascapular notch: proposal of classification

Introduction  

The size and shape of the suprascapular notch (SSN) may be a factor in suprascapular nerve entrapment. The aim of the study was to determine the variation of the SSN of 86 scapulae in the Polish people.     

An anatomic study of the spinal accessory nerve: extended harvest permits direct nerve transfer to distal plexus targets

An anatomic study of the distal spinal accessory nerve (SAN) to determine the number of myelinated axons and feasibility of posterior harvest for direct neurotization of distal targets was performed. Ten fresh human cadavers were studied. A supraclavicular approach was performed followed by a posterior approach. The relationship of the SAN to bony landmarks (T1 spinous process, acromioclavicular joint, posterolateral corner of the acromium, and angle at the superior medial border of the scapula) as well as maximal harvestable length was recorded. After posterior dissection, the SAN was mobilized and the ability to reach both anterior infraclavicular and posterior targets was assessed. Axon counts were also performed at the proximal, mid, and distal points along the course of the nerve. The posteriorly harvested SAN was identified reliably with respect to bony landmarks. When harvested posteriorly, the SAN could reach the infraclavicular part of the brachial plexus (i.e., terminal branches), and posteriorly, the suprascapular nerve (SSN) both proximal and distal to the suprascapular ligament, the latter for selective reinnervation of the infraspinatus branch. The average number of myelinated fibers at the proximal end of the nerve was 1,328 axons, at the mid-way point was 1,021 axons, and at terminal end of the nerve was 817 axons. Harvest of the SAN from a posterior approach based on these landmarks is feasible, allowing direct transfer of the nerve to the infraclavicular brachial plexus and to the SSN both proximal and distal to the suprascapular ligament, without the use of interposition nerve grafts.     

肩胛上神经卡压机制的临床解剖学研究

目的　探讨肩胛上神经卡压症的解剖学机制,为临床诊断和治疗提供解剖学依据。 方法　22具(男13具,女9具)44侧成尸标本,解剖观测肩胛上切迹,冈盂切迹的形态特点以及肩胛上神经走行、分支及分布的解剖学特点,所测数据统计学处理。 结果　肩胛上切迹类型：U型占40.91%（18侧）,浅U型占22.73%（10侧）,大弧型占27.27%（12侧）,方形占9.01%（4侧）四种。肩胛上切迹的厚度为（1.55±0.36）mm。肩胛上神经主干与冈上肌支所成角为(86.04±1.28)°。冈下肌支的入肌点,有22.73%在该肌的起点处,77.27%在中或外1/3处。冈盂切迹的厚度在（6.82±1.21）mm 。肩胛上神经自肩胛上孔穿出点至肩胛冈基底部的高度为（11.13±0.21）mm;至冈盂切迹的水平距离为（14.03±0.64）mm 。肩胛上神经转折角为（49.65±1.63）°。 结论　肩胛上切迹的类型、肩胛上切迹和冈盂切迹的厚度,肩胛上神经转折角的大小、神经主干与冈上肌支的角度以及冈下肌支的入肌点等均是肩胛上神经卡压的危险因素。     

Ultrasonographic evaluation and morphometric measurements of the suprascapular notch

Background:  The aim of this study was to define the sonographic evaluation and morphometric measurements of the suprascapular notch. Methods  The suprascapular notch was evaluated by ultrasound on both sides in 50 volunteers (25 males, 25 females). By means of ultrasound, the notch width, the notch depth and the distance between the skin and the notch base (skin–notch base interval) were measured and imaging of the superior transverse scapular ligament was attempted. Furthermore, imaging of the suprascapular artery and vein was performed by Doppler ultrasound. Results  On the measurements performed, the notch was found to be deeper in men than in women on both the right (P = 0.022) and the left (P = 0.011) sides. Taking all volunteers into account without grouping sex, no differences were detected between the two sides with respect to the measurements of the notch width, notch depth and distance between the skin and the notch base. The superior transverse scapular ligament was demonstrated in 48 (96%) of 50 volunteers. On color Doppler ultrasound, the artery–vein complex was visualized in a total of 43 (86%) volunteers. Conclusions  Suprascapular notch measurements and the visualization of the anatomical neighborhood, which may be beneficial for the suprascapular nerve blockade procedure, can be successfully performed by the use of high-frequency ultrasound imaging.     

Willis环三维时间飞跃法磁共振成像的形态、解剖变异及脑底动脉直径测量

通过三维时间飞跃法磁共振成像建立正常国人Willis环的形态、解剖变异及各组成血管直径的正常参考值,探讨其临床意义,决定在Willis环的解剖中是否存在年龄或性别差异。153例健康志愿者和体检者做头MRA检查,显示Willis环,根据其完整情况分为I型(Willis环完整)、II型(Willis环前循环完整后循环不完整)、III型(Willis环前循环不完整后循环完整)、IV型(Willis环前后循环均不完整),根据各血管发育情况,各型又分为典型型、变异型、发育不良型和混合型4种亚型,并对各组成血管直径进行测量。结果表明:153例中,I型占34.64%,II型占47.71%,III型占5.23%,IV型占12.42%。各型及各亚型的年龄、性别差异无显著性。前交通动脉显示率为87.58%,后交通动脉显示率为65.34%,胚胎型大脑后动脉出现率为20.92%。MRA评价Willis环的形态和变异有重要的临床意义,脑底动脉MRA正常值可作为临床判断脑血管疾病的参考。     

肩胛上神经阻滞穿刺点的研究及其临床意义

目的为肩胛上神经阻滞麻醉提供解剖学基础。方法解剖观察102例成人尸体肩胛区,在肩胛冈中部上方切除一长宽约8 cm的区域,显露和观察肩胛上神经、血管及肩胛上横韧带的位置及其毗邻关系;测量肩胛上神经与肩峰内侧的距离和肩胛冈上方的距离及其深度;在肩胛骨上角与肩峰的连线上,测量肩胛上神经与肩峰内侧的距离。结果肩胛上神经距离肩峰内侧（6.29±0.71）cm、上方（1.93±0.59）cm、肩胛上神经在此点距皮肤的深度为（3.63±0.55）cm。在肩胛骨上角与肩峰连线上,肩胛上神经距离肩峰内侧（6.37±0.87）cm。结论肩胛上神经阻滞麻醉穿刺点位于肩峰内侧6.29 cm、正上方1.93 cm、此点深度3.63 cm,或在肩胛骨上角与肩峰连线上,肩胛上神经距离肩峰内侧6.37 cm。     

Variations in the extensor grooves on the radial styloid process in Chinese population

Purpose

The aim was to provide anatomical data for local blocking treatment of de Quervain’s disease through investigating features and classification of the first extensor groove on the radial styloid process.

Methods

Two hundred and eighty-four specimens of the intact distal extremity of dry radii from Chinese corpses were investigated and measured systematically in this study. Morphological features of the extensor grooves on the radial styloid process were observed by visual inspection. Correlation parameters of variability were measured with a vernier caliper.

Results

The study showed that the most prevalent group was Type I (the extensor groove that was deep and divided into two sub-grooves by a tiny bony ridge) accounting for 63.73 % (181 specimens). Seventy-nine specimens belonged to Type II (the extensor groove without the tiny bony ridge) accounting for 27.82 % and 24 specimens belonged to Type III (almost without any extensor groove on the radius) accounting for 8.45 %. The distance between the processus of the palmar bony ridge and the processus of the dorsal bony ridge (defined as AC) was 11.55 ± 1.32 mm. The distance between the processus of the palmar bony ridge and the sharp point of the styloid process of the radius (defined as AB) was 17.09 ± 1.99 mm.

Conclusions

The extensor groove could provide a subjective safe operation range for the steroid injections, which could be defined depending on the bony landmarks, which are easy to identify in the body surface. This anatomical variation is important in the management of de Quervain’s disease.     

Fibrocartilage at the entheses of the suprascapular (superior transverse scapular) ligament of man—a ligament spanning two regions of a single bone

The suprascapular ligament converts the suprascapular notch into a foramen separating the vessels and nerve of the same name. It connects 2 regions of the same bone and does not cross any joint, and no mechanical function has yet been attributed to it. Nevertheless, variations in its thickness and length, and its tendency to ossify, suggest that the ligament responds to changes in mechanical load. This should be reflected in the composition of the extracellular matrix. The primary purpose of the present study is to demonstrate that the suprascapular ligament has fibrocartilaginous entheses (i.e. insertion sites), even though there is no obvious change in insertional angle that directly results from joint movement. Such a change is more typical of tendons or ligaments that cross highly mobile joints. The complete ligament (including both entheses) was removed from 7 cadavers shortly after death and fixed in 90% methanol. Cryosections were immunolabelled with a panel of monoclonal antibodies against collagens (types I, II, III, VI), glycosaminoglycans (chondroitin 4 sulphate, chondroitin 6 sulphate, dermatan sulphate and keratan sulphates), proteoglycans (aggrecan and versican) and link protein. Both entheses were strongly fibrocartilaginous, and a moderately fibrocartilaginous matrix was also detected throughout the remainder of the ligament. The extracellular matrix of both entheses labelled strongly for type II collagen, aggrecan and link protein. The fibrocartilaginous character of the entheses suggests that the insertion sites of the ligament are subject to both compressive and tensile loading and are regions of stress concentration. This in turn probably reflects the complex shape of the scapula and the presence of a conspicuous indentation (the suprascapular notch) near the ligament. The loading patterns may reflect either the attachment of muscles and/or the forces transmitted to the suprascapular ligament from the neighbouring coracoclavicular ligament.     

成人下颌孔及周边骨性结构的解剖特点

目的:研究成人下颌孔及周边骨性结构的解剖特点,为临床手术操作提供解剖参考和依据.方法:由口腔专业教师确定各解剖结构的位置并标记,用游标卡尺、量角器、直尺和圆规对下颌骨进行测量,记录数据并进行统计学分析.结果:有76.00％的下颌孔位于下颌支内面中点之后,有87.00％的下颌孔位于下颌支内面中点之上;下颌孔的内外径为3....