OBJECTIVE: To conduct a comprehensive analysis of proximal humeral anatomical characteristics in the Chinese population utilizing three-dimensional reconstruction technology, thereby establishing an evidence base for the enhancement of shoulder hemiarthroplasty procedures and the development of domestically manufactured prostheses. METHODS: The study cohort comprised 30 patients (60 shoulders) presenting with cervicoscapular pain between July 2023 and June 2025, with equal gender distribution (15 males and 15 females); age distribution ranged from 20 to 75 years (mean, 53.7 years). Data acquisition was performed via high-resolution CT imaging (technical parameters: slice thickness 0.625 mm, voltage 120 kV, current 150 mA, matrix 512×512). Subsequently, CT datasets were processed in DICOM format using Mimics17.0 software for three-dimensional reconstruction, followed by quantitative assessment via Imageware12.0 software to evaluate key proximal humeral parameters: humeral head dimensions (coronal diameter, sagittal diameter, surface curvature diameter, thickness), angular measurements [neck-shaft angle, retroversion angle (retroversion angle 1 was the angle between the humeral head axis and the line connecting the medial and lateral condyles, and retroversion angle 2 was the angle between the humeral head axis and the tangent of the trochlea)], and positional metrics (medial offset, posterior offset). Statistical analysis incorporated Pearson correlation coefficients to determine parameter relationships, with comparative evaluations conducted across demographic variables including gender, height, body mass, and age. RESULTS: Quantitative analysis yielded the following measurements: humeral head coronal diameter (41.8±3.6) mm, sagittal diameter (39.1±4.1) mm, surface curvature diameter (44.9±4.6) mm, thickness (17.2±1.8) mm, neck-shaft angle (128.4±4.2)°, retroversion angle 1 (16.9±8.9)°, retroversion angle 2 (21.4±11.3)°, medial offset (3.8±1.7) mm, and posterior offset (5.1±1.6) mm. Correlation analysis demonstrated the most pronounced positive relationship between humeral head surface curvature diameter and thickness ( r=0.966, P=0.001), with additional significant positive correlations observed between surface curvature diameter and coronal diameter ( r=0.842, P=0.001), posterior offset and retroversion angle 1 ( r=0.766, P=0.001), and coronal diameter and thickness ( r=0.727, P=0.001). Demographic analysis revealed significantly greater dimensions in males compared to females for humeral head surface curvature diameter, coronal diameter, sagittal diameter, and thickness ( P<0.05), with these parameters demonstrating progressive increases corresponding to height ( P<0.05). With the exception of neck-shaft angle, all parameters exhibited a positive correlation with body mass. No significant age-related differences were detected across parameters ( P>0.05). CONCLUSION The proximal humeral morphology in the Chinese population exhibits substantial variability, necessitating optimization of prosthetic designs based on population-specific anatomical metrics to enhance the efficacy of personalized clinical interventions.
Humans ; Middle Aged ; Male ; Female ; Aged ; Imaging, Three-Dimensional/methods* ; Adult ; Tomography, X-Ray Computed/methods* ; Humerus/diagnostic imaging* ; Shoulder Joint/surgery* ; Hemiarthroplasty/methods* ; Humeral Head/anatomy & histology* ; Young Adult ; Clinical Relevance

BACKGROUND: The aim of this study was to determine if there were significant differences in glenohumeral joint morphology between North American and East Asian populations that may influence sizing and selection of shoulder arthroplasty systems. METHODS: Computed tomography reconstructions of 92 North American and 58 East Asian patients were used to perform 3-dimensional measurements. The proximal humeral position was normalized in all patients by aligning it with the scapular plane utilizing anatomic landmarks. Measurements were performed on the humerus and scapula and included coronal and axial humeral head radius, humeral neck shaft and articular arc angles, glenoid height and width, and critical shoulder angle. Glenohumeral relationships were also measured and included lateral distance to the greater tuberosity and acromion, abduction lever arm, and acromial index. Parametric and nonparametric statistical analyses were used to compare population metrics. RESULTS: East Asian glenohumeral measurements were significantly smaller for all linear metrics (p < 0.05), with the exception of acromial length, which was greater than in the North American cohort (p < 0.001). The increase in acromial length affected all measurements involving the acromion including abduction lever arms. No difference was found between the neck shaft and articular angular measurements. CONCLUSIONS: The East Asian population exhibited smaller shoulder morphometrics than their North American cohort, with the exception of an extended acromial overhang. The morphologic data can provide some additional factors to consider when choosing an optimal shoulder implant for the East Asian population, in addition to creating future designs that may better accommodate this population.
African Americans/*statistics & numerical data ; Aged ; Anthropometry ; Asian Continental Ancestry Group/*statistics & numerical data ; European Continental Ancestry Group/*statistics & numerical data ; Female ; Humans ; Male ; Prosthesis Design ; Republic of Korea/epidemiology ; Shoulder/*anatomy & histology ; Shoulder Joint/*anatomy & histology ; Shoulder Prosthesis ; United States/epidemiology

Acupuncture Points ; Acupuncture Therapy ; Adult ; Female ; Hand ; anatomy & histology ; Humans ; Male ; Meridians ; Middle Aged ; Periarthritis ; Shoulder Injuries

Acromioclavicular Joint ; anatomy & histology ; injuries ; surgery ; Fracture Fixation ; instrumentation ; methods ; Humans ; Male ; Shoulder Dislocation ; surgery

Animal shoulder models are important in the investigation of the natural history of various pathologic conditions and for evaluation of the effectiveness of different treatments and biomaterials. The characteristics of animal shoulder models that may be used for rotator cuff related experiments are different with regard to the anatomy, behavioral pattern, advantages and disadvantages in application to each other. The lower primates and all the non-primate species, except the tree kangaroo, were neither functional overhead nor had a true rotator cuff. Utilizing more advanced primates, or perhaps even the tree kangaroo would be ideal and the most relevant to man as they possess a true rotator cuff. However, ethical concerns, costs, and many limitations in obtaining primates generally preclude the use of these animals for such research. Finally we should consider the differences in comparative anatomy and behavioral pattern of each animal model during performance or interpretation of rotator cuff experiments.
Anatomy, Comparative ; Animals ; Biocompatible Materials ; Macropodidae ; Models, Animal ; Natural History ; Primates ; Rotator Cuff* ; Shoulder*

Animal shoulder models are important in the investigation of the natural history of various pathologic conditions and for evaluation of the effectiveness of different treatments and biomaterials. The characteristics of animal shoulder models that may be used for rotator cuff related experiments are different with regard to the anatomy, behavioral pattern, advantages and disadvantages in application to each other. The lower primates and all the non-primate species, except the tree kangaroo, were neither functional overhead nor had a true rotator cuff. Utilizing more advanced primates, or perhaps even the tree kangaroo would be ideal and the most relevant to man as they possess a true rotator cuff. However, ethical concerns, costs, and many limitations in obtaining primates generally preclude the use of these animals for such research. Finally we should consider the differences in comparative anatomy and behavioral pattern of each animal model during performance or interpretation of rotator cuff experiments.
Anatomy, Comparative ; Animals ; Biocompatible Materials ; Macropodidae ; Models, Animal ; Natural History ; Primates ; Rotator Cuff ; Shoulder

INTRODUCTIONDetailed anatomical knowledge of the suprascapular notch (SSN) is important for the management of entrapment neuropathy and interventional procedures. The objective of the present study was to collect data on the morphological features and anatomical variations of the SSN in an Indian population.

METHODSWe studied 268 human scapulae of unknown sex (126 right-sided, 142 left-sided) taken from the Department of Anatomy, Dayanand Medical College and Hospital, India. SSNs were classified as either type I, II, III, IV or V, based on the shape of the inferior border of the incisura, and comparison of the SSN's vertical and transverse diameters. The shape of the SSN (i.e V- or U-shaped), if present, was also recorded.

RESULTSType II SSN was the most common (50.00%), followed by type I, type IV and type III (32.46%, 9.70% and 7.84%, respectively). For right-sided type II SSNs, the transverse and vertical diameters were 9.1 ± 3.2 mm and 5.2 ± 1.9 mm, respectively, while those for left-sided type ll SSNs were 9.2 ± 2.4 mm and 5.1 ± 1.8 mm, respectively. Generally, the transverse diameter of type II SSN was found to be greater than that of type III SSN. The incidence of U-shaped SSN was 51.49%, while that of V-shaped SSN was 2.99%.

CONCLUSIONThis study of the morphometrical characteristics and anatomical variations of SSN provides an anatomical database of SSN in the Indian context. This database will be of use in surgical procedures, as the information can be used to ensure adequate access to and complete decompression of the suprascapular nerve.

Humans ; India ; Nerve Compression Syndromes ; diagnosis ; Scapula ; anatomy & histology ; surgery ; Shoulder Joint ; injuries

OBJECTIVETo explore the distribution rules of proximal and distal focus of muscle meridian region in scapulohumeral periarthritis.

METHODSThree hundred and six shoulder joints of affected side were selected in 216 patients of scapulohumeral periarthritis. Under the guidance of muscle meridian theory, with the anatomical characteristics of muscle meridian focuses, the frequency and location where proximal and distal focus appeared were calculated by palpation.

RESULTSThe percentages of the frequency that the focus of muscle meridian of Hand-Yangming, Hand-Shaoyang, Hand-Taiyang, and three yin meridians of hand appeared at proximal points of shoulder joint were 25.6% (1 146/5 657), 30.9% (1 749/5 657), 19.0% (1 075/5 657), and 24.5% (1 387/5 657), respectively, the focuses of muscle meridian region were Jianyuci, Juguci, Xiaoshuoci, Naohuici, etc. The percentages of the frequency that the focus of muscle meridian region appeared at distal points of shoulder joint were 31.77% (287/905), 23.2% (210/905), 10.9% (99/905), and 34.1% (304/905), the focuses of muscle meridian were Yangxici, Shousanlici, Yangchici, etc.

CONCLUSIONThe location and frequency of proximal and distal focus of muscle meridian in scapulohumeral periarthritis are closely related with the anatomical structure and biomechanical characteristics of the shoulder joints, thus new therapy for scapulohumeral periarthritis is implied.

Acupuncture Points ; Acupuncture Therapy ; Adult ; Aged ; Female ; Humans ; Male ; Meridians ; Middle Aged ; Palpation ; Periarthritis ; diagnosis ; therapy ; Shoulder Joint ; anatomy & histology

We developed a three-dimensional finite element model of the shoulder glenohumeral joint after shoulder arthroplasty including humerus shaft, scapular, scapular cartilage and eight muscles, while each of the muscles was simulated with 50 spring elements. To reduce the element number and improve the analytical precision, we used mixed tetrahedral and hexahedral elements in the model. We then used the model to calculate the biomechanics of the shoulder glenohumeral joint after hemiarthroplasty during humeral external rotation. Results showed that the maximum joint reaction force was 374.72 N and the maximum contact stress was 6. 573 MPa together with the contact areas at 40 degrees external rotation. These might be one of the reasons for prosthetic disarticulation, and would provide theoretical bases to prosthetic design.
Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Humeral Head ; anatomy & histology ; Models, Anatomic ; Prosthesis Design ; Range of Motion, Articular ; Rotation ; Shoulder Joint ; anatomy & histology

BACKGROUND: The ability to explore the anatomy has improved our appreciation of the brachial anatomy and the quality of regional anesthesia. Using real-time ultrasonography, we investigated the cross-sectional anatomy of the brachial plexus and of vessels at the axillary fossa in Koreans. METHODS: One hundred and thirty-one patients scheduled to undergo surgery in the region below the elbow were enrolled after giving their informed written consent. Using the 5-12 MHz linear probe of an ultrasound system, we examined cross-sectional images of the brachial plexus in the supine position with the arm abducted by 90degrees, the shoulder externally rotated, and the forearm flexed by 90degrees at the axillary fossa. The results of the nerve positions were expressed on a 12-section pie chart and the numbers of arteries and veins were reported. RESULTS: Applying gentle pressure to prevent vein collapse, the positions of the nerves changed easily and showed a clockwise order around the axillary artery (AA). The most frequent positions were observed in the 10-11 section (79.2%) for the median, 1-2 section (79.3%) for the ulnar, 3-5 section (78.4%) for the radial, and 8-9 section (86.9%) for the musculocutaneous nerve. We also noted anatomical variations consisting of double arteries (9.2%) and multiple axillary veins (87%). CONCLUSIONS: Using real-time ultrasonography, we found that the anatomical pattern of the major nerves in Koreans was about 80% of the frequent position of individual nerves, 90.8% of the single AA, and 87% of multiple veins around the AA.
Anatomy, Cross-Sectional ; Anesthesia, Conduction ; Arm ; Arteries ; Axilla ; Axillary Artery ; Axillary Vein ; Brachial Plexus* ; Elbow ; Forearm ; Humans ; Musculocutaneous Nerve ; Shoulder ; Supine Position ; Ultrasonography* ; Veins