The patterns of proximal attachments of the popliteus muscle: form and function

The proximal attachments of the popliteus muscle exhibit some variability in the literature, leading to questions regarding function. The anatomic variability of the proximal attachments of popliteus muscles in Thais was studied in order to compare with the previous reported literature by carefully tracking its fibers caudo-cephalically. The sites of the proximal attachments of popliteus muscles found in this study were at the lateral femoral condyle (100%), the posterior horn of the lateral meniscus (63%) and the fibular head (52.1%). Our result also reveals the difference of the strength of the attachment at the lateral meniscus, having some relationship with the attachment at the fibular head, which corresponds with the concept of form and function.     

腘肌腱形态特点及其临床意义

目的 为临床腘肌腱损伤的诊断及关节镜下治疗提供解剖学基础.方法 对21个成人膝关节标本进行解剖,观察腘肌腱的形态及其与周围结构关系.结果 腘肌腱出现恒定,起始于腓侧副韧带股骨附着处前下方,穿过股二头肌腱和腓侧副韧带的深面在胫骨平台下与腘肌肌腹相连接.腘肌腱的长度为(40.12±0.91)mm,起点宽度为(6.19±0.27)mm,止点宽度为(6.46±0.35)mm,起点厚度为(3.38±0.24)mm,止点厚度为(3.62±0.25)mm.结论 腘肌腱是组成膝关节后外侧复合体的重要结构之一;深入了解其形态特点,对关节镜下腘肌腱损伤诊断、治疗及解剖重建有重要意义.     

腘肌腱和腓侧副韧带股骨止点的测量及其临床意义

目的　为临床膝关节后外侧角重建术股骨侧骨隧道的定位提供解剖学资料。 方法　选取男女各30例膝关节标本,对膝关节后外侧角仔细解剖分离,测量腓侧副韧带和腘肌腱股骨附丽部中心与股骨外上髁位置关系、两者中心点的距离以及附丽部的面积。 结果　腓侧副韧带附着面积为(47.25±　14.69)mm2,其中男性为(50.22±9.72)mm2,大于女性的(44.29±12.33)mm2;腘肌腱附着面积为(56.18±13.88)　mm2,其中男性为(60.57±12.44)mm2,大于女性的(51.79±13.68)mm2。腓侧副韧带附丽部中心在股骨外上髁近端(1.29±2.73)mm,后方(3.53±2.12)mm,腘肌腱附丽部中心在股骨外上髁远端(8.47±3.34)mm,后方　(3.86±2.09)mm。腓侧副韧带和腘肌腱两者股骨附丽部中心的距离平均为(10.12±3.06)mm,男性为(11.32±　3.69)mm,女性为(8.92±3.25)mm。 结论　两者附丽部的面积和中心距离存在性别差异（P<0.05）,本实验的解剖数据可以为临床重建术中定位骨隧道提供参数值。     

颊肌的解剖学研究及其临床意义

目的：阐明颊肌的血液供应,为新型颊肌粘膜瓣设计提供解剖学基础。方法：对10具新鲜尸体标本20侧面区进行解剖,从颈总动脉远心端注入红色乳胶,在2具尸体标本面静脉内注入兰色乳胶。显露颊肌及其血管和神经。结果：面动脉分别发出后颊支、下颊支和前颊支进入颊肌,后颊与颊动脉相互吻合。上齿槽后动脉和眶下动脉发出上颊支分别进入颊肌上界的后部与前部。这些分支相互吻合。颊肌静脉在颊肌后部形成颊静脉丛,分2～4支注入面静脉,或经颊静脉注入翼丛或上颌静脉。结论：面动脉为颊肌的主要供血动脉。以进入颊肌任何一方血管为蒂的颊肌粘膜瓣均可存活。本文设计了2种新的岛状颊肌粘膜瓣。     

股骨上段髓腔径线研究及其临床意义

目的:为设计符合国人股骨髓腔形状的人工股骨柄提供股骨上段髓腔几何形态学基础。方法:成人股骨标本共160根,每根标本分别拍照正位、侧位、45°内斜位和45°外斜位的X线片。对小转子顶点上方20mm(D)、小转子顶点(E)、小转子顶点下方20mm(F)、峡部近端(L)、峡部(G)和峡部远端(M)处各平面髓腔各径线进行测量。结果:所测结果均符合或接近正态分布。股骨头位置在小转子顶点上方(47.3±5.9)mm;各处髓腔宽度:D(40.2±4.5)mm,E(23.4±3.6)mm,F(16.8±2.8)mm,G[内径(10.0±2.6)mm,外径(24.0±2.6)mm];L及M在小转子顶点下方(68.5±12.1)mm,(144.4±17.5)mm处;G在小转子顶点下(103.9±14.3)mm处;在相同平面,各径线的相关系数为0.239￣0.802。结论:西方人的髓腔较国人的大,进口假体与国人有时难以匹配,或术中需要将髓腔扩大,以适应假体大小。峡部只是在正位片上显现,其前后径及双斜径并无明显变窄。同一平面髓腔各方向径线呈高度正相关,选择及设计假体时应遵循此规律。     

胫骨近端后侧数字化三维形态学测量及临床意义

目的　研究胫骨近端后侧数字化形态学测量的方法,探讨其对胫骨后侧平台骨折诊疗的意义。  方法　对60例健康成人胫骨干燥标本进行CT扫描,图像导入Mimics 10.01软件建立数字化三维模型,测量相关解剖参数,分析其分布规律与相关关系。  结果　后侧正中高度（8.46±1.62）mm,后内侧高度（12.27±1.93）mm,后内侧斜坡长度（14.71±2.27）mm,后内侧平台斜坡角（132.02±11.62）°,后内侧斜坡骨干角（147.28±10.72）°,后外侧高度（11.31±1.74）mm,后外侧斜坡长度（14.45±2.26）mm,后外侧平台斜坡角（124.01±9.81）°,后外侧斜坡骨干角（141.88±9.09）°,所有测量参数双侧差异无统计学意义（P＞0.05）。后正中高度、后外侧高度和后外侧斜坡长度与胫骨全长具有相关性（P＜0.01）。   结论　本研究建立的胫骨近端数字化三维模型仿真度高,解剖参数测量结果精确度高,能为胫骨后侧平台骨折临床治疗和内固定物设计提供解剖学依据。     

Anatomical study of the arrangement and attachments of the human medial pterygoid muscle

The authors have studied the medial pterygoid muscle on 179 fresh cadavers using anatomical dissection and magnetic resonance imaging (MRI). The aim of this study was to define the general morphology and architectural organisation of the human medial pterygoid. Plane by plane dissection, anatomical sections in different spatial planes on half heads and isolated blocks demonstrated that the medial pterygoid has different architectural disposition and insertional zones from those which are normally described. The study has shown that the muscle has a typical penniform structure made up of seven alternating muscular/aponeurotic layers and that the tendinous intramuscular sheets were particularly well developed. This allows supporting a future functional study.     

Muscular architecture of the popliteus muscle and the basic science implications

BackgroundThe function of the popliteus muscle is largely treated as a static stabilizer and has a lack of basic muscular architectural data to enable study of its dynamic function. A large volume of literature supports its static function and the essential need for reconstruction in the posterolateral knee when injured to restore knee stability.Hypothesis/purposeWe hypothesize that the popliteus muscle is more significant as a dynamic presence in the knee.MethodsA collection of popliteus architectural data was collected from 28 cadaver specimens (mean (SD) 76 years (11)). Physiological cross-sectional area of the popliteus and semimembranosus muscles were calculated from muscle volume and fiber length to power future muscle force prediction models. Posterior knee muscle trajectories were measured with respect to the longitudinal axis of the tibia. A 2-tailed T test was performed.ResultsSignificant differences between males and females were found for both the popliteus (p = 1.1E − 05) and semimembranosus (p = 2.0E–05) muscle volumes. Significant differences between males and females were also found in PCSA for the popliteus (p = 0.005) and semimembranosus (p = 4.1E–05) muscles. There were no significant differences in fiber length, overall muscle length (with tendon removed), age, and orientation.ConclusionFurther consideration should be given to include the popliteus muscle as a dynamic entity in the knee given its mechanical properties, trajectory, and prior biomechanical evidence showing when and how it is activated. The present study provides data that may shape future directions of research and treatment with regard to posterolateral corner injuries and ligamentous balancing of the knee.     

鼻肌的应用解剖及其临床意义

目的：研究鼻肌的解剖分部、功能及其临床意义。方法：３０具成人尸体及１具单侧唇裂死胎（胎龄８个月），采用由浅入深，逐层显示和顺肌肉走行为原则的大体解剖方法。结果：鼻肌是起源于上颌骨切牙窝的一组扁平肌，按肌纤维走行分为４部分，即横部、翼部、基底部和小柱部。唇裂死胎解剖中未见裂侧之基底部和小柱部。结论：鼻肌是外鼻下端主要的肌肉组织，对外鼻的形态维持起重要作用。唇裂患者裂侧鼻肌发育畸形，隧导致了两侧鼻肌肌力的失衡，进而导致或加剧了单侧唇裂患者复杂多样的外鼻畸形。     

骨质疏松时股骨上段髓腔形态学特点及其临床意义

目的:探讨骨质疏松时股骨上段髓腔的形态学变化,为老年人工髋关节置换术提供依据。方法:160根股骨,每个标本分别拍照正位、侧位、45°内斜位和45°外斜位的X线片,记录Singh指数,测量股骨上段髓腔,研究Singh指数和股骨上段髓腔的关系。结果:Singh指数为7￣5的62个标本中髓腔扩大者6.5%(4),不扩大者93.5%(58);Singh指数为4￣1的95个标本中髓腔扩大者67.4%(64),不扩大者32.6%(31);Singh指数越大,股骨上段髓腔越窄,Singh指数越小,股骨上段髓腔越宽大;骨质疏松时股骨髓腔扩大是全方位的,其骨皮质吸收以髓腔内面明显。结论:(1)骨质疏松标本髓腔扩大峡部不明显,假体设计要考虑到峡部不明显时如何使股骨柄远端与股骨骨髓腔形态相匹配,对老年人可将柄下端适当加粗,以适应髓腔变化。(2)对骨质疏松老年人,选择假体前要拍照股骨全长的正、侧位及双斜位X线片,对髓腔形态有较全面的评估,以选择适合的假体。     

Anatomical relationships and scapular attachments of the supraspinatus muscle

Summary Ten anatomical preparations and 15 MRI scans (Magnetic Resonance Imaging) performed on healthy subjects were used to define accurately the lateral attachments and anatomical boundaries of the supraspinatus m. Using 5 frozen specimens sectioned in the plane corresponding to the sagittal oblique MRI plane, it was possible to calculate quantitatively the ratio between the bony contours (O) and muscles (M) of the supraspinous fossa. This ratio was maximal (O/M=2.4) for the section passing through the plane which included the coracoid process anteriorly and the spine of the scapula posteriorly (“Y” section). Five dissections on unembalmed subjects demonstrated that the postero-lateral origin of supraspinatus m. extended further laterally than classically described. This observation was confirmed in the 15 MRI subjects which showed that the supraspinatus m. may arise as far laterally as the “Y” section on MRI in 53% of cases. A quantitative evaluation of atrophy of the supraspinatus m. using MRI is possible with a knowledge of these two parameters.

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Rapports et insertions scapulaires du muscle supra-épineux

Résumé Dix préparations anatomiques et 15 IRM (Imagerie par Résonance Magnétique) sur sujets sains ont été utilisées pour préciser les insertions latérales du m. supra-épineux et les limites de sa loge d'insertion. Cinq préparations congelées et coupées dans le plan correspondant à celui de l'incidence sagittaleoblique de l'IRM, ont permis de calculer le rapport quantitatif entre les contours osseux (O) et musculaires (M) de la fosse supra-épineuse: ce rapport est maximal (O/M=2,4) pour une coupe passant dans le plan comprenant le processus coraco?de en avant et l'épine de la scapula en arrière (coupe en Y). Cinq dissections sur sujets non embaumés ont montré que l'insertion postéro-latérale du m. supra-épineux s'étendait latéralement au delà des insertions classiquement décrites. Cette observation a été confirmée par 15 IRM sur sujets témoins qui ont montré que le m. supra-épineux présentaient encore des insertions au niveau de la coupe IRM “en Y” dans 53 % des cas. La connaissance de ces deux paramètres permet de proposer une technique d'évaluation quantitative de l'atrophie du m. supra-épineux à l'aide de l'IRM.

     

Branched myofibers in long-term whole muscle transplants: a quantitative study

Orthotopic transplants of whole extensor digitorum longus muscles were performed on six 4-6-week-old 129 ReJ mice. One hundred days posttransplantation, the animals were killed and the regenerated muscles were processed for electron microscopy. The grafts contained polygonal-shaped myofibers with persistent central nuclei, organized into discrete muscle fascicles. No central area of fatty infiltration or fibrosis was observed. The mean number of myofibers in a regenerating transplanted muscle, as determined from an ultrathin section taken from the graft's widest girth, was 631 (SEM = +/- 59), a reduction of approximately 32% from that found in age-matched control muscle (Ontell et al., 1983). By following the myofibers in spaced, serial ultrathin sections along their length, it was found that the branched, regenerating myofibers found in immature grafts of normal muscle (Ontell et al., 1982) persisted in stabilized, long-term transplanted muscle. The frequency of branching was determined by following each fiber found at the widest girths of four of the grafts in spaced, serial ultrathin sections (15-micron intervals) for approximately 2% of the total length of the grafts. Over this distance, 6.6% of the fibers were involved in the branching phenomenon. The persistence of branched fibers in long-term grafts and the frequency with which the branching phenomenon was found to occur may have physiological consequences and should be investigated.     

Anatomic study of popliteus complex of the knee in a Chinese population

This study explored the anatomic relationship of the popliteus complex (PC) and collected anatomic data of PC in a Chinese population. The anatomic study was performed using 81 formalin-fixed knees. The femoral attachment of the popliteus tendon could be classified into three types with respect to femoral attachment of the lateral collateral ligament. The popliteofibular ligament presented as ligament (87.7%) or fascia (12.3%), originating from the musculotendinous junction of the popliteus muscle or just proximal to it. Given the great variability of the posterolateral structures, reconstructive surgeons should design a method based on individual anatomic features, rather than a fixed reconstructive surgery.     

The attachments of the conus elasticus to the laryngeal skeleton: Physiologic and clinical implications

The attachments of the inferior and dorsal extensions of the lateral parts of the conus elasticus (CE) are not fully understood. A re-investigation was done in plastinated serial sections of 20 adult human larynges. The CE consists of a coherent sheet of connective tissue fibers dividing into two layers toward the inferior anchorage to the cricoid arch, and the posterior anchorage to the cricoid lamina. Caudally, the medial fiber layer is continuous with the submucous fibro-elastic membrane of the trachea and is not connected to the cricoid cartilage. The lateral caudal fiber layer is attached to the superior rim of the cricoid arch. Dorsally, both layers of the CE are fixed to the cricoid lamina, the lateral sheet to the lateral edge of the cartilage, the medial sheet to its anterior perichondrium near the midline. Towards the cricoarytenoid joint, the dorsal extension of the CE divides into a caudal and a cranial sheet including a fold of adipose tissue at the base of the arytenoid cartilage. The cranial layer extends towards the vocal process, the caudal layer radiates into the joint capsule and may therefore influence the complicated joint mechanics. The firm attachments of the CE to the cricoid cartilage probably counteract deformations of the CE during phonation. An insufficient fixation of the CE may contribute to an obstruction of the airways causing sleep apnea. © 1996 Wiley-Liss, Inc.     

An anatomic study of the attachments on the condylar process of the mandible: muscle bundles from the temporalis

Purpose

The aim of this study was to evaluate anatomically the relationship between bone and muscles by detailed observation of the bone shape and the structure of muscles to facilitate an understanding of the function of the muscles involved in jaw movement.

Methods

36 specimens of 24 Japanese cadavers were examined. The insertion areas were marked using a radiopaque marker and examined by micro-computed tomography. For morphological observation, we used 101 condylar processes. In addition, we made histological sections in some specimens to observe the detailed attachments of the muscle.

Results

Based on the micro-CT images and dissection findings, the lateral pterygoid muscle was found to be most frequently inserted into the anterior impression and attached to the medial impression of the process. According to the histological observations, the lateral pterygoid muscle mainly inserted to the condylar process. The micro-CT images indicated that the obvious bony ridge was lateral to the pterygoid fovea on the condylar process in all specimens. The midmedial muscle bundle of the temporalis was attached to the ridge. Based on the morphological observations, the ridge was situated on the lateral area of the condylar process.

Conclusions

Since dysfunction of the temporomandibular joint is likely closely related to both the lateral pterygoid muscle and also the temporalis, further studies are necessary to evaluate the function of these muscles and consider jaw movement.

     

股骨偏心距的测量及其临床意义

目的测量股骨偏心距的大小并探讨其临床意义。方法对100例正常双髋关节X线片进行影像学测量,测量参数包括股骨偏心距、颈干角、股骨头直径、外展肌力臂、体重力臂、小转子中点及其上下20mm的冠状径、峡部直径和髓腔闪烁指数等,SPSS10.0统计学软件分析股骨偏心距与外展肌力臂、体重力臂、股骨髓腔各解剖参数的相关关系及男女各参数间的差异,并将测量结果与国内外学者的测量参数进行比较。结果本组股骨偏心距大小为(36.64±5.31)mm;股骨偏心距与外展肌力臂呈明显的正相关(r=0.73,P0.01),与股骨颈干角呈负相关(r=-0.46,P0.01),与其它股骨近端解剖参数无明显相关性。男女两性间股骨偏心距、颈干角、股骨头直径、外展肌力臂有显著性差异(P0.05)。本组股骨偏心距、颈干角与白种人有显著性差异(P0.01)。结论股骨偏心距大小为(36.64±5.31)mm,重建股骨偏心距有利于恢复外展肌力臂,重建正常髋关节生物力学。     

胫骨平台后外侧髁“边缘曲线”的影像学研究及临床意义

研究胫骨平台后外侧髁弧形轮廓的角度及长度,为临床钢板塑形和设计新型水平带状钢板提供理论依据。 方法　收集50例成人膝关节CT数据[男31 例,女19例,平均（37.68±12.76）岁]。在横断面平扫图像下,以腓骨头尖初次显露为标准图片,在胫骨平台外侧髁边缘标记A、B、C、D、E五点。分段测量并记录其连线的长度与夹角,计算后外侧髁曲线长度和曲线的转折角。 结果　胫骨平台后外侧髁曲线长度平均（44.04±11.33）mm (19.50~75.50 mm), 由前向后的三点折弯角平均为（163.36±7.67）°、（127.95±20.85）°和（160.50±11.99）°。手术中按照该测量参数进行钢板折弯与塑形,5例患者术后CT显示,钢板形状与胫骨平台后外侧髁贴服紧密,对皮质轮廓包绕良好。 结论　按照骨骼测量的边缘曲线参数进行术中钢板折弯和设计新型解剖钢板,能够提高钢板与后外侧髁的贴合程度。     

An analysis of the popliteus muscle in man, dog, and pig with a reconsideration of the general problems of muscle function

On the basis of general considerations of muscle functions and by means of mechanical and measuring methods and by computer analysis, it is shown that the popliteus muscle of man, dog, and pig is basically an extensor, regardless of whether femur or tibia are considered as resting. The traditional doctrine claiming a flexor function of the popliteus muscle has to be revised. In spite of the basic extending function, its effect in actual extension, especially against the weight of the entire body, is evidently most doubtful. Never has its rotatory function been doubted. Its role in reversing the compulsory rotation at the beginning of flexion can now easily be explained: since it is an extensor, the flexion would cause its passive elongation, against which its mere tonus causes rotation.     

Perisynaptic satellite cells in human external intercostal muscle: a quantitative and qualitative study

It is not known whether or not satellite cell nuclei are more common in the vicinity of motor endplates than in extrasynaptic regions of human muscle, as in animals. If so, perisynaptic satellite cells may have a role in preserving neuromuscular function. We compared the frequencies of satellite cell nuclei and of myonuclei in perisynaptic and extrasynaptic regions of human external intercostal muscle, and found an absolute as well as a relative increase of perisynaptic satellite cells. The mean frequency of satellite cell nuclei per sarcomere was 0.016 in perisynaptic and 0.00003 in extrasynaptic regions. The mean frequency of myonuclei per sarcomere was 0.098 in perisynaptic and 0.014 in extrasynaptic regions. We could not demonstrate any influence of aging on satellite cell distribution. Perisynaptic satellite cells had many processes, and some features suggested a more active state. These cells might add to the pool of junctional myonuclei for synthesis of acetylcholine-receptor molecules or help in the repair of the postsynaptic membrane. Alternatively, they may synthesize basal lamina substances that are specific for the endplate.