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

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