盂肱关节骨性结构测量的研究进展

与现代人工肩关节假体设计有关的各项解剖参数测量方法很多,包括标本解剖学测量、X线平片测量、CT测量等。由于测量方法及定义线的不一致,导致较多参数测值差别太大,给肩关节假体设计及手术带来不便。本文就盂肱关节骨性结构解剖参数的测量进行综述,提出测量方法应统一到CT或MRI三维重建测量上来,以满足现代肩关节假体设计解剖与解剖关系重建的核心理念。     

肩关节手术入路中的应用解剖学研究

目的:观测肩关节的形态结构及周围结构的特点,为临床手术提供资料。方法:解剖观察20具成人肩关节周围肌肉及其血管神经等重要结构。结果:三角肌外侧部深面主要有横过骨肌肉之间的腋神经前支和旋肱后血管,后侧深部主要有冈上肌冈下肌、小圆肌、回边孔、三边孔及其内部结构。(2)冈上肌肌腱密切粘着于肩关节囊例上部肌腱表面,于肩峰深面有肩峰下深液囊,有时与三角肌下滑液囊相通。(3)肩关节的血液供应主要靠旋肱前动脉及肩胛后动脉．肩关节靠近大血管主干,血供丰富、血流速度快。(4)神经界面,肩关节周围的界面有三角肌冈下肌间隙,三角肌胸大肌间隙,三角肌与喙肱肌、肱二头肌间隙、冈下肌小圆肌间隙。结论:肩关节结构极为复杂,解剖肩关节时应避免损伤重要组织结构。     

The use of sequential MR image sets for determining tibiofemoral motion: reliability of coordinate systems and accuracy of motion tracking algorithm

The use of magnetic resonance imaging has been proposed by many investigators for establishment of joint reference systems and kinematic tracking of musculoskeletal joints. In this study, the intraobserver and interobserver reliability of a strategy to establish anatomic reference systems using manually selected fiducial points were quantified for seven sets of MR images of the human knee joint. The standard error of the measurement of the intraobserver and interobserver errors were less than 2.6 degrees, and 1.2 mm for relative tibiofemoral orientation and displacement, respectively. An automated motion tracking algorithm was also validated with a controlled motion experiment in a cadaveric knee joint. The controlled displacements and rotations prescribed in our motion tracking validation were highly correlated to those predicted (Pearson's correlation = 0.99, RMS errors = 0.39 mm, 0.38 degree). Finally, the system for anatomic reference system definition and motion tracking was demonstrated with a set of MR images of in vivo passive flexion in the human knee.     

Muscle efficiency in total shoulder prosthesis implantation: dependence on position of the humeral head and rotator cuff function]

Modern shoulder prostheses permit an anatomic reconstruction of the joint, although the biomechanical advantages are not proven. The goal of this study was to investigate the relationship between position of the humeral head and function of the shoulder prosthesis (muscle efficiency). Shoulder elevation-motion and rotator cuff defects were simulated in vitro in a robot-assisted shoulder simulator. The EPOCA Custom Offset shoulder prosthesis (Argomedical AG, Cham, CH) was implanted in seven normal shoulders (77 +/- 20 kg, 55 +/- 14 years). Active elevation was simulated by hydraulic cylinders, and scapulothoratic motion by a specially programmed industrial robot. Muscle efficiency (elevation-angle/muscle-force of the deltoid muscle) was measured in anatomic (ANA), medialised (MED) and lateralised (LAT) positions of the humeral head, with or without rotator cuff muscle deficiency. Medialisation increased efficiency by 0.03 +/- 0.04 deg/N (p = 0.022), lateralisation decreased it by 0.04 +/- 0.06 deg/N (p = 0.009). Supraspinatus muscle deficiency increased the deltoid force required to elevate the arm, and thus decreased efficiency (ANA p = 0.091, MED p = 0.018, LAT p = 0.028). The data confirm that the position of the humeral head affects the mechanics of total shoulder arthroplasty. Medialisation increases efficiency of the deltoid muscle and may prove useful in compensating isolated supraspinatus muscle deficiency. Lateralisation, in contrast, leads to an unfavorable situation.     

Fluid collection within the synovial sheath of the tendon of the flexor hallus longus muscle in the tarsal joint of rats: an anatomic variant detectable with magnetic resonance imaging

Magnetic resonance (MR) images of the right tarsal joint of 22 normal male Han:Wistar rats were acquired using a 4.7 T magnet. An intermediate-high signal area associated with the tendon of the flexor hallus longus muscle was noticed in three rats on T2-weighted images. These areas appeared as an intermediate-high signal on lightly T2-weighted images, but appeared as an iso-signal to muscle structure on proton density weighted images. Histology preparations showed that such areas were caused by a sizable fluid collection within the synovial sheath of the tendon of the flexor hallus longus muscle, with all other joint structures appearing normal. This anatomic variant could be potentially regarded as a lesion on T2-weighted MR images, such as inflamed tissue with oedema, especially when the spatial resolution and/or signal-to-noise ratio are not optimal.     

Glenohumeral translation during active and passive elevation of the shoulder - a 3D open-MRI study

Despite its importance for the understanding of joint mechanics in healthy subjects and patients, there has been no three-dimensional (3D) in vivo data on the translation of the humeral head relative to the glenoid during abduction under controlled mechanical loading. The objective was therefore to analyze humeral head translation during passive and active elevation by applying an open MR technique and 3D digital postprocessing methods. Fifteen healthy volunteers were examined with an open MR system at different abduction positions under muscular relaxation (30-150 degrees of abduction) and during activity of shoulder muscles (60-120 degrees ). After segmentation and 3D reconstruction, the center of mass of the glenoid and the midpoint of the humeral head were determined and their relative position calculated. During passive elevation, the humeral head translated inferiorly from +1.58mm at 30 degrees to +0. 36mm at 150 degrees of abduction, and posteriorly from +1.55mm at 30 degrees to -0.07mm at 150 degrees of abduction. Muscular activity brought about significant changes in glenohumeral translation, the humeral head being in a more inferior position and more centered, particularly at 90 and 120 degrees of abduction (p<0.01). In anterior/posterior direction the humeral head was more centered at 60 and 90 degrees of abduction during muscle activity. The data demonstrate the importance of neuromuscular control in providing joint stability. The technique developed can also be used for investigating the effect of muscle dysfunction and their relevance on the mechanics of the shoulder joint.     

Use of virtual, interactive, musculoskeletal system (VIMS) in modeling and analysis of shoulder throwing activity

Our purpose in this study was to apply the virtual, interactive, musculoskeletal system (VIMS) software for modeling and biomechanical analysis of the glenohumeral joint during a baseball pitching activity. The skeletal model was from VIMS library and muscle fiber attachment sites were derived from the visible human dataset. The muscular moment arms and function changes are mainly due to the large humeral motion involved during baseball pitching. The graphic animation of the anatomic system using VIMS software is an effective tool to model and visualize the complex anatomical structure of the shoulder for biomechanical analysis.     

Shoulder muscle function depends on elbow joint position: an illustration of dynamic coupling in the upper limb

Shoulder muscle function has been documented based on muscle moment arms, lines of action and muscle contributions to contact force at the glenohumeral joint. At present, however, the contributions of individual muscles to shoulder joint motion have not been investigated, and the effects of shoulder and elbow joint position on shoulder muscle function are not well understood. The aims of this study were to compute the contributions of individual muscles to motion of the glenohumeral joint during abduction, and to examine the effect of elbow flexion on shoulder muscle function. A three-dimensional musculoskeletal model of the upper limb was used to determine the contributions of 18 major muscles and muscle sub-regions of the shoulder to glenohumeral joint motion during abduction. Muscle function was found to depend strongly on both shoulder and elbow joint positions. When the elbow was extended, the middle and anterior deltoid and supraspinatus were the greatest contributors to angular acceleration of the shoulder in abduction. In contrast, when the elbow was flexed at 90°, the anterior deltoid and subscapularis were the greatest contributors to joint angular acceleration in abduction. This dependence of shoulder muscle function on elbow joint position is explained by the existence of dynamic coupling in multi-joint musculoskeletal systems. The extent to which dynamic coupling affects shoulder muscle function, and therefore movement control, is determined by the structure of the inverse mass matrix, which depends on the configuration of the joints. The data provided may assist in the diagnosis of abnormal shoulder function, for example, due to muscle paralysis or in the case of full-thickness rotator cuff tears.     

Morphology and function of the shoulder joint of bats (Mammalia: Chiroptera)1

The shoulder joint of the Microchiroptera shows a remarkable morphological variation that has been studied in 20 individual bats from 15 species and 11 families. The basic morphology of the shoulder joint, with a globular humeral head and a corresponding glenoid cavity, is found in the Megachiroptera and, within the Microchiroptera, in the Rhinopomatidae. Besides this basic shoulder joint, there are two derived joint types: the derived and specialized shoulder joint with a single articular surface on the scapula and a more-or-less oblong humeral head, and the derived and specialized shoulder joint with secondary articular surfaces on the trochiter and on the dorsal aspect of the scapula. The first type of derived joint is most strikingly developed in the Mormoopidae and the Noctilionidae, the second one in the Vespertilionidae and the Molossidae. It is suggested that both types of derived shoulder joints have the functional significance of reducing the pronatory movements of the abducted forearm during the downstroke of the wing-beat cycle. This suggested function of the secondary shoulder joint is a new approach to understanding this very peculiar structure. In species with these specialized shoulder joints, the downstroke musculature is comparatively better developed and the M. serratus ant. post. div. comparatively less well developed. A hypothesis is offered to explain and combine the osteological and myological findings. Each of the derived types of shoulder joints has developed independently more than once through parallel evolution.     

An MRI Study of Symptomatic Adhesive Capsulitis

Background

Appilication of MR imaging to diagnose Adhesive Capsulitis (AC) has previously been described. However, there is insufficient information available for the MRI analysis of AC. This study is to describe and evaluate the pathomorphology of the shoulder in Asian patients with AC compared to healthy volunteers.

Methodology/Principal Findings

60 Asian patients with clinically diagnosed AC and 60 healthy volunteers without frozen shoulder underwent MRI of the shoulder joint. All subjects who were age- and sex-matched control ones underwent routine MRI scans of the affected shoulder, including axial, oblique coronal, oblique sagittal T1WI SE and coronal oblique T2WI FSE sequences. Significant abnormal findings were observed on MRI, especially at the rotator cuff interval. The coracohumeral ligament (CHL), articular capsule thickness in the rotator cuff interval as well as the fat space under coracoid process were evaluated. MRI showed that patients with adhesive capsulitis had a significantly thickened coracohumeral ligament and articular capsule in the rotator cuff interval compared to the control subjects (4.2 vs. 2.4 mm, 7.2 vs. 4.4 mm; p<0.05). Partial or complete obliteration of the subcoracoid fat triangle was significantly more frequent in patients with adhesive capsulitis compared with control subjects (73% vs. 13%, 26% vs. 1.6%; p<0.001). Synovitis-like abnormality around the long biceps tendon was significantly more common in patients with adhesive capsulitis than in control subjects. With regards to the inter-observer variability, two MR radiologists had an excellent kappa value of 0.86.

Conclusions/Significance

MRI can be used to show characteristic findings in diagnosing AC. Thickening of the CHL and the capsule at the rotator cuff interval and complete obliteration of the fat triangle under the coracoid process have been shown to be the most characteristic MR findings seen with AC.     

Effects of anterior offsetting of humeral head component in posteriorly unstable total shoulder arthroplasty: Finite element modeling of cadaver specimens

A novel technique of “anterior offsetting” of the humeral head component to address posterior instability in total shoulder arthroplasty has been proposed, and its biomechanical benefits have been previously demonstrated experimentally. The present study sought to characterize the changes in joint mechanics associated with anterior offsetting with various amounts of glenoid retroversion using cadaver specimen-specific 3-dimensional finite element models. Specimen-specific computational finite element models were developed through importing digitized locations of six musculotendinous units of the rotator cuff and deltoid muscles based off three cadaveric shoulder specimens implanted with total shoulder arthroplasty in either anatomic or anterior humeral head offset. Additional glenoid retroversion angles (0°, 10°, 20°, and 30°) other than each specimen׳s actual retroversion were modeled. Contact area, contact force, peak pressure, center of pressure, and humeral head displacement were calculated at each offset and retroversion for statistical analysis. Anterior offsetting was associated with significant anterior shift of center of pressure and humeral head displacement upon muscle loading (p<0.05). Although statistically insignificant, anterior offsetting was associated with increased contact area and decreased peak pressure (p > 0.05). All study variables showed significant differences when compared between the 4 different glenoid retroversion angles (p < 0.05) except for total force (p < 0.05). The study finding suggests that the anterior offsetting technique may contribute to joint stability in posteriorly unstable shoulder arthroplasty and may reduce eccentric loading on glenoid components although the long term clinical results are yet to be investigated in future.     

The role of the biceps brachii in shoulder elevation.

The biceps brachii is a bi-articular muscle affecting motion at the shoulder and elbow. While its' action at the elbow is well documented, its role in shoulder elevation is less clear. Therefore, the purpose of this project was to investigate the influence of shoulder and elbow joint angles on the shoulder elevation function of the biceps brachii. Twelve males and 18 females were tested on a Biodex dynamometer with the biceps brachii muscle selectively stimulated at a standardized level of voltage. The results indicated that both shoulder and elbow joint angles influence the shoulder joint elevation moment produced by the biceps brachii. Further analysis revealed that the elevation moment was greatest with the shoulder joint at 0 degrees and the elbow flexed 30 degrees or less. The greatest reduction in the elevation moment occurred between shoulder angles of 0 degrees and 30 degrees . The shoulder elevation moment was near zero when shoulder elevation reached or exceeded 60 degrees regardless of elbow angle. These results clarify the role of the biceps in shoulder elevation, as a dynamic stabilizer, and suggest that it is a decelerator of the arm during the throwing motion.     

Quantitative Analysis of the Deltoid and Rotator Cuff Muscles in Humans and Great Apes

The shoulder is one of the anatomic regions differentiating orthograde primates (gibbons, orangutans, gorillas, chimpanzees, bonobos, and humans) from the rest of the pronograde primates. Orthograde primates are characterized by a dorsal position of the scapula and a more lateral orientation of the glenoid cavity. This anatomic pattern, together with adaptations in related osteological structures and muscles, serves to facilitate the elevation of the upper extremity in the scapular plane. We quantified the proportions of the muscles comprising the principal functional and stabilizing components of the glenohumeral joint —deltoid, subscapularis, supraspinatus, infraspinatus, and teres minor— in 3 species of orthograde primates: Pongo pygmaeus, Pan troglodytes, and Homo sapiens. Our objective was to determine whether quantifiable differences in these muscles relate to the functional requirements of the types of locomotion used by these 3 species: suspension/vertical climbing, knuckle-walking, and bipedalism. We observed a close similarity between the proportional mass of these muscles in Homo sapiens and Pongo pygmaeus, whereas Pan troglodytes displayed a unique anatomic pattern, particularly in the subscapularis, which may be due to differences in how the glenohumeral joint is stabilized in a great ape knuckle-walker. Our findings may help explain the high incidence of subacromial impingement syndrome in humans.     

MRI in shoulder joint instability

The paper provides the results of MRI studies in 100 patients having complaints of pain and impaired movements in the shoulder joint in order to establish a diagnosis. Sixty-three patients were found to have MRI signs of shoulder joint instability (SJI). The paper presents and states the found MRI symptoms of SJI. The author concludes that MRI of the shoulder joint in its instability should be used appropriately as it may early reveal changes in the articular osseous, cartilaginous, and soft tissues, which is useful in diagnosing and choosing a treatment.     

MRI in shoulder joint instability

The paper provides the results of MRI studies in 100 patients having complaints of pain and impaired movements in the shoulder joint in order to establish a diagnosis. Sixty-three patients were found to have MRI signs of shoulder joint instability (SJI). The paper presents and states the found MRI symptoms of SJI. The authors concludes that MRI of the shoulder joint in its instability should be used appropriately as it may early reveal changes in the articular osseous, cartilaginous, and soft tissues, which is useful in diagnosing and choosing a treatment.     

“四个自由度肌电控制全臂假肢”肩关节机构的设计

全臂假肢肩关节结构，不但要符合人手臂的外形特征，而且在结构设计的布局上还要考虑仿生性和造型的美观逼真。由于在肩关节处要承受相当大的力矩，肩关节机构要经得起前臂的较大负载外力，所以功能可靠更为重要。因此关肩节机构的 设计具有相当的难度。本机构利用蜗轮蜗杆传动的优点，来实现肩关节前屈后伸运动。克服了链传间隙大的缺点，缩短了力臂改善了肩关节处的受力状态，并且在假肢的上臂安装了上臂手动旋转环，其既可在任意     

A kinematic model of the shoulder complex to evaluate the arm-reachable workspace

Upper-arm evaluation including shoulder motion in physiotherapy has no three-dimensional tool for an arm-functioning evaluation, which hampers an uniform, objective comparison. Human shoulder complex models suffer from lack of shoulder girdle kinematic data. A kinematic shoulder-complex model with six degrees of freedom is proposed as the composition of the inner joint representing the shoulder-girdle joints and outer joint representing the glenohumeral joint. The outer shoulder joint has three perpendicular rotations: adduction/abduction, retroflexion/flexion and internal/external rotation of the humerus. The inner shoulder joint has two rotations, depression/elevation and retraction/protraction, and one translation, which are all dependent on the elevation angle of the humerus. The human arm-reachable workspace that represents the area within reach of the wrist is calculated on the basis of the shoulder-complex model and the additional elbow-joint direct kinematics. It was demonstrated that cross-sections of the calculated workspace are in agreement with the measured arm-reachable workspace in all three anatomical planes. The arm-reachable workspace volume and graphics were calculated and a comparison of the arm's workspaces during a patient's shoulder treatment was made. The obtained numerical and graphical arm-reachable workspaces can be used for arm-functioning evaluations in rehabilitation and ergonomics.     

Characterization of the shoulder net joint moment during manual wheelchair propulsion using four functional axes

Understanding how individuals distribute mechanical demand imposed on their upper extremity during physically demanding activities provides meaningful insights to preserve function and mitigate detrimental mechanical loading of the shoulder. In this study, we hypothesized that parameterization of the shoulder net joint moment using four functional axes could characterize distribution tendencies about the shoulder during manual wheelchair propulsion and that regardless of demographics, a shoulder flexor dominant NJM distribution would be predominantly used by individuals with paraplegia (n = 130). Forces and kinematics of the upper extremity and trunk were quantified using motion capture and an instrumented wheel during steady state manual wheelchair propulsion at self-selected fast speeds on a stationary ergometer. The results indicate that parsing out the internal/external rotation component of the shoulder net joint moment about the upper arm and distributing the remainder across the three orthogonal axes of the torso was successful in identifying common shoulder net joint moment distribution techniques used across individuals with paraplegia during manual wheelchair propulsion. Distribution tendencies were predominantly flexor dominant across injury level, gender, time since injury, body mass index, and height demographics. The 4-axis parameterization of the shoulder NJM effectively differentiated moment distribution tendencies used by individuals during manual wheelchair propulsion using a functionally relevant representation of shoulder kinetics. Use of the four-axis parameterization of joint kinetics in future studies is expected to provide important insights that can advance knowledge, preserve function, and inform clinical decisions.     

Cineradiographic study of forelimb movements during quadrupedal walking in the brown lemur (Eulemur fulvus, Primates: Lemuridae)

Movements of forelimb joints and segments during walking in the brown lemur (Eulemur fulvus) were analyzed using cineradiography (150 frames/sec). Metric gait parameters, forelimb kinematics, and intralimb coordination are described. Calculation of contribution of segment displacements to stance propulsion shows that scapular retroversion in a fulcrum near the vertebral border causes more than 60% of propulsion. The contribution by the shoulder joint is 30%, elbow joint 5%, and wrist joint 1%. Correlation analysis was applied to reveal the interdependency between metric and kinematic parameters. Only the effective angular movement of the elbow joint during stance is speed-dependent. Movements of all other forelimb joints and segments are independent of speed and influence, mainly, linear gait parameters (stride length, stance length). Perhaps the most important result is the hitherto unknown and unexpected degree of scapular mobility. Scapular movements consist of ante-/retroversion, adduction/abduction, and scapular rotation about the longitudinal axis. Inside rotation of the scapula (60 degrees -70 degrees ), together with flexion in the shoulder joint, mediates abduction of the humerus, which is not achieved in the shoulder joint, and is therefore strikingly different from humeral abduction in man. Movements of the shoulder joint are restricted to flexion and extension. At touch down, the shoulder joint of the brown lemur is more extended compared to that of other small mammals. The relatively long humerus and forearm, characteristic for primates, are thus effectively converted into stride length. Observed asymmetries in metric and kinematic behavior of the left and right forelimb are caused by an unequal lateral bending of the spinal column.