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

Objective:To report the application of our self-made Kirschner wire connecting rod combined with a conventional intramedullary nail extractor in difficult extraction of intramedullary devices.Methods:From January 2012 to August 2017, 10 patients with a hard-to-remove intramedullary device were treated at Department of Orthopaedics, The Fifth Hospital Affiliated to Xinjiang Medical University. They were 7 males and 3 females with a mean age of (40.0±9.0) years. In cases where no relevant extractor was available for the intramedullary device or it was impossible to connect the extractor connecting rod to the tail of the intramedullary device, the Kirschner wire was bent and pulled through the screw hole or the hole newly drilled at the tail of the intramedullary device to be tied or fixed with a conventional extractor connecting rod to form an effective connection. Next, our self-made Kirschner wire connecting rod was used to pull out the intramedullary device. In this cohort, 7 intramedullary nails in the tibia, 1 femoral intramedullary nail, 1 humeral intramedullary nail, and 1 tibial elastic nail were removed. The difficult extraction was due to "cold welding" of the tail cap of the intramedullary nail in 3 cases, mismatch between the screw rod of the extractor and the tail screw hole of the intramedullary nail in 4 cases, and unavailability of relevant removal tools in 3 cases. The time for intramedullary device removal, blood loss and postoperative adverse reactions were recorded.Results:Of this cohort, 9 patients underwent simple removal of the intramedullary device and 1 patient replacement of the intramedullary device. The total time for removal of an intramedullary device was (2.3±0.8) h, ranging from 1.0 to 3.2 h. The amount of blood loss was (159.0±61.0) mL, ranging from 80 to 250 mL. The follow-up was (14.5±2.2) months, ranging from 11 to 18 months. There was no infection or fracture associated with implant removal.Conclusion:Application of our self-made Kirschner wire connecting rod in combination with a conventional intramedullary nail extractor is an easy operation to successfully extract hard-to-remove intramedullary implants, requiring no more special instruments.