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。     

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。     

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.     

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.     

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.     

Morphological study of the inferior transverse scapular ligament

The suprascapular nerve can be compressed by the inferior transverse scapular ligament (ITSL), also known as the spinoglenoid ligament, and this entrapment results in dysfunction of the external rotation of the upper arm owing to isolated weakness of the infraspinatus muscle. The morphology of the ITSL has not been adequately characterized. The aim of this study was to clarify the morphological characteristics of the ITSL. In total, 110 shoulders from 72 cadavers were dissected in this study. The ITSL was present in 73 (66.4%) of the 110 specimens, and comprised membrane in 40 (36.4%), ligament in 25 (22.7%), and both membrane and ligament in eight (7.3%). This structure could be classified into three types on the basis of its shape: band‐like (33.6%, type I), triangular (15.5%, type II), or irregular (17.3%, type III). In the spinoglenoid notch, the suprascapular nerve was always close to the lateral margin of the scapular spine. The length of the ligament between its origin and insertion sites ranged from 8.7 to 23.4 mm at its superior margin and from 8.9 to 17.5 mm at its inferior margin. The ligament width and thickness at its midportion ranged from 1.6 to 10.0 mm and from 0.1 to 1.2 mm, respectively. The results of this study improve understanding of the ITSL and will be helpful for successful diagnoses and treatments for selective suprascapular nerve entrapment. Clin. Anat. 27:707–711, 2014. © 2013 Wiley Periodicals, Inc.     

肩胛上神经及其冈上肌干支入肌点的应用解剖

目的探讨肩胛上神经的行程和冈上肌干支入肌点,为肩部疾病的诊治提供解剖形态学基础。方法对15具(30侧)成人上肢标本,观察肩胛上神经及其分支冈上肌支的走行、分段、体表定位和冈上肌支入肌点进行研究。结果肩胛上横韧带前段的肩胛上神经主干长4.03～5.23(4.36±0.60)cm,外径2.21～4.45(4.22±0.63)mm;骨纤维管内肩胛上神经外径与入管前一样;出管后肩胛上神经的分支冈上肌干支长1.24～0.90(3.78±0.23)cm,外径为0.54～2.01(1.82±0.20)mm。冈上肌干支入肌点距孔后为1.15～2.01(8.22±5.20)mm。结论①肩胛上神经行程较长,穿越骨纤维管位置恒定,易发生卡压,其体表定位位于距离肩峰最外端约6 cm处。②冈上肌干支伴血管行走,距孔后约1 cm入肌体,位置相对恒定,其体表定位相当于锁骨锥状结节的后方约3 cm处,入肌内分有前、中、后三支。     

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.     

Subclavius posticus muscle: supernumerary muscle as a potential cause for thoracic outlet syndrome

During routine dissection a subclavius posticus muscle was found on the left side of a male cadaver. This muscle arose from the upper margin of the scapula and transverse scapular ligament, inserted in the superior side of the first rib cartilage, and was innervated by a small branch from the suprascapular nerve. The anatomical relationships of the supernumerary muscle with the brachial plexus and the subclavian artery is suggestive of a possible cause of the thoracic outlet syndrome and therefore of clinical significance.     

肩胛骨安全区的解剖

目的通过解剖学研究,评估各个肩胛骨同一区域的差异,获得一个能有效避免医源性神经损伤的安全区,为施行和改良关节镜手术提供数据参考。方法选取100个保存完好的干肩胛骨,测量肩胛体、关节盂和肩胛上神经的走行路径,用统计学方法对所得数据进行处理和分析。结果肩胛体纵向最长距离(A)、肩胛体横向最长距离(B)、关节盂纵向最长距离(C)、关节盂横向最长距离(D)与肩胛切迹到盂上结节的距离(E)的皮尔森相关系数分别为:0.797、0.786、0.792、0.687;与冈下窝的后盂缘中线到肩胛冈嵴内侧缘的距离(F)的皮尔森相关系数分别为:0.368、0.381、0.403、0.396。根据统计学分析,国人的安全区即盂上结节到肩胛切迹的安全距离是2.2cm,冈下窝的后盂缘中线到肩胛冈嵴内侧缘的安全距离是1.3cm。结论对肩胛骨的相关指标进行评估,以便获得安全区以利于手术的进行,避免肩胛上神经的损伤;同时,线性方程预测也应该被应用于获取患者的肩胛上神经的相关解剖学数据。     

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.     

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.     

Anatomical evidence for a uniquely positioned suprascapular foramen

The suprascapular foramen is a rare but not exceptional variation of the suprascapular notch. The suprascapular notch and suprascapular foramen could lead to pain and muscles atrophy because of nerve compression. In this study, we present a suprascapular foramen which does not correspond to a nerve’s trajectory but rather corresponds to a specific bone formation that increases the surface area for muscle attachment. As a consequence, its presence cannot be taken as an indication for neurolysis, contrary to ossification of the foramen in its normal anatomical position. Moreover, this unique foramen is distinguishable from a classical suprascapular foramen on radiographs and, especially, on CT scan images.     

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。     

Anterior coracoscapular ligament and suprascapular nerve entrapment

A reduction in the height of the suprascapular foramen may predispose to entrapment of the suprascapular nerve. In this study, 16 of 27 cadavers (60%) demonstrated a heretofore unreported ligament located on the anterior aspect of the suprascapular foramen. In 11 of the 27 cadavers (41%), the ligament was observed bilaterally. The ligament decreased the foraminal height from the normative value of 5.6 +/- 0.4 to 2.3 +/- 0.4 mm (mean +/- SEM). Because this ligament, for which we propose the term anterior coracoscapular ligament (ACSL), substantially narrows the suprascapular foramen, it should be considered as a possible etiologic factor in suprascapular nerve entrapment.     

肩胛上神经卡压综合征的电生理诊断

目的：探讨肩胛上神经卡压综合征电生理诊断方法。方法：对10例肩胛上神经卡压综合征的病人应用肌电图（EMG）观察自发电位,检测肩胛上神经支配肌冈上肌、冈下肌;腋神经支配肌三角肌;肩胛背神经支配肌提肩胛肌的复合肌肉动作电位（CMAP）,观察指标为潜伏期、波幅的变化。结果：10例病人冈上肌均见自发电位,募集反应减弱,CMAP潜伏期延长,波幅降低,且波形离散。结论：电生理是诊断和鉴别诊断肩胛上神经卡压综合征的重要辅助手段。     

Anatomical considerations for safe scapular resection in snapping scapula syndrome

Background  

The resection of the superomedial angle of the scapula in snapping scapula syndrome is associated with potential risk of injury to the suprascapular nerve. The aim of the present study was to determine the distance of site of resection on the upper border of the scapula from the suprascapular notch during arthroscopic resection of the superomedial angle using standard superior Bell’s and medial portals at the middle of medial border.     

Bilateral suprascapular nerve entrapment

Bilateral suprascapular nerve entrapment syndrome is very rare. It presents with shoulder pain, weakness and atrophy of the supraspinatus and infraspinatus muscles. We present a twenty-year old man having a history of bilateral shoulder pain associated with weakness. Electromyographic studies revealed signs of a lesion that caused a neupraxic state of the left suprascapular nerve, moderate axonal loss of the right suprascapular nerve and denervation of the right suprascapular muscle. The patient was treated with physical and medical therapy. Due to worsening of the symptoms, a surgical operation was performed by the excision of the transverse scapular ligaments bilaterally. His pain, weakness and atrophy had diminished on examination six weeks later. Suprascapular nerve entrapment should be considered in patients with shoulder pain, particularly those with weakness and atrophy of the supraspinatus and infraspinatus muscles.     

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.