OBJECTIVE: To compare the biomechanical properties of personalized Y-shaped plates with horizontal plates, vertical plates, and traditional Y-shaped plates in the treatment of distal humeral intra-articular fractures through finite element analysis, and to evaluate their potential for clinical application. METHODS: The study selected a 38-year-old male volunteer and obtained a three-dimensional model of the humerus by scanning his upper limbs using a 64-slice spiral CT. Four types of fracture-internal fixation models were constructed using Mimics 19.0, Geomagic Wrap 2017, Creo 6.0, and other software: horizontal plates, vertical plates, traditional Y-shaped plate, and personalized Y-shaped plate. The models were then meshed using Hypermesh 14.0 software, and material properties and boundary conditions were defined in Abaqus 6.14 software. AnyBody 7.3 software was used to simulate elbow flexion and extension movements, calculate muscle strength, joint forces, and load torques, and compare the peak stress and maximum displacement of the four fixation methods at different motion angles (10°, 30°, 50°, 70°, 90°, 110°, 130°, 150°) during elbow flexion and extension. RESULTS: Under dynamic loading during elbow flexion and extension, the personalized Y-shaped plate exhibits significant biomechanical advantages. During elbow flexion, the peak internal fixation stress of the personalized Y-shaped plate was (28.8±0.9) MPa, which was significantly lower than that of the horizontal plates, vertical plates, and traditional Y-shaped plate ( P<0.05). During elbow extension, the peak internal fixation stress of the personalized Y-shaped plate was (18.1±1.6) MPa, which was lower than those of the other three models, with significant differences when compared with horizontal plates and vertical plates ( P<0.05). Regarding the peak humeral stress, the personalized Y-shaped plate model showed mean values of (10.9±0.8) and (13.1±1.4) MPa during elbow flexion and extension, respectively, which were significantly lower than those of the other three models ( P<0.05). Displacement analysis showed that the maximum displacement of the humerus with the personalized Y-shaped plate during elbow flexion was (2.03±0.08) mm, slightly higher than that of the horizontal plates, but significantly lower than that of the vertical plates, showing significant differences ( P<0.05). During elbow extension, the maximum displacement of the humerus with the personalized Y-shaped plate was (1.93±0.13) mm, which was lower than that of the other three models, with significant differences when compared with vertical plates and traditional Y-shaped plates ( P<0.05). Stress contour analysis showed that the stress of the personalized Y-shaped plate was primarily concentrated at the bifurcation of the Y-shaped structure. Displacement contour analysis showed that the personalized Y-shaped plate effectively controlled the displacement of the distal humerus during both flexion and extension, demonstrating excellent stability. CONCLUSION The personalized Y-shaped plate demonstrates excellent biomechanical performance in the treatment of distal humeral intra-articular fractures, with lower stress and displacement, providing more stable fixation effects.
Humans ; Male ; Adult ; Healthy Volunteers ; Finite Element Analysis ; Tomography, Spiral Computed ; Models, Anatomic ; Biomechanical Phenomena ; Humeral Fractures, Distal/surgery* ; Fracture Fixation, Internal/instrumentation* ; Bone Plates ; Computer Simulation ; Precision Medicine/methods* ; Elbow Joint/surgery* ; Elbow/surgery* ; Humerus/surgery* ; Torque ; Stress, Mechanical ; Intra-Articular Fractures/surgery* ; Prosthesis Design/methods* ; Imaging, Three-Dimensional ; Range of Motion, Articular

OBJECTIVE: To evaluate the feasibility and short-term effectiveness of three-dimensional (3D)-printed customized porous acetabular components for reconstruction of extensive acetabular bone defects during primary total hip arthroplasty (THA). METHODS: The clinical data of 8 patients with extensive acetabular bone defects, who were treated with 3D-printed individualized porous acetabular components between July 2018 and January 2022, were retrospectively analyzed. The cohort comprised 4 males and 4 females with an average age of 48 years ranging from 34 to 56 years. Acetabular bone defects were classified as Paprosky type ⅢA in 3 cases and type ⅢB in 5 cases. The causes of acetabular destruction were hip tuberculosis (5 cases), pigmented villonodular synovitis (2 cases), and syphilitic arthritis (1 case). Visual analogue scale (VAS) score and Harris hip score (HHS) were used to evaluate the pain relief and hip function before and after operation. Reconstruction outcomes were further assessed by imaging results [X-ray film and Tomosynthesis Shimadzumetal artefact reduction technology (T-SMART)], and the mechanical properties were evaluated by finite element analysis. RESULTS: The operation time ranged from 174 to 195 minutes (mean, 187 minutes), and intraoperative blood loss ranged from 390 to 530 mL (mean, 465 mL). All 8 patients were follow-up 26-74 months (mean, 44 months). Among the 5 patients with tuberculosis, none experienced postoperative recurrence. At last follow-up, the VAS score was 0.3±0.5 and the HHS score was 87.9±3.7, both significantly improved compared to preoperative values ( t=25.170, P<0.001; t=-28.322, P<0.001). X-ray films at 2 years after operation demonstrated satisfactory matching between the 3D-printed customized acetabular component and the acetabulum. The postoperative center of rotation of the operated hip was shifted by (2.1±0.5) mm horizontally and (2.0±0.7) mm vertically relative to the contralateral side, with both offsets showing significant differences compared to preoperative values ( t=24.700, P<0.001; t=55.230, P<0.001). T-SMART imaging showed satisfactory osseointegration at the implant-host bone interface. No complications such as aseptic loosening or screw breakage was observed during follow-up. Finite element analysis showed that the acetabular component had good mechanical properties. CONCLUSION The application of 3D-printed individualized porous acetabular components in the reconstruction of extensive acetabular bone defects demonstrated precise anatomical reconstruction, stable mechanical support, and good functional performance in short-term follow-up, offering a potential alternative for acetabular defect reconstruction in primary THA.
Humans ; Middle Aged ; Male ; Female ; Printing, Three-Dimensional ; Arthroplasty, Replacement, Hip/instrumentation* ; Acetabulum/diagnostic imaging* ; Adult ; Follow-Up Studies ; Retrospective Studies ; Hip Prosthesis ; Prosthesis Design ; Porosity ; Treatment Outcome ; Plastic Surgery Procedures/methods*

OBJECTIVE: To quantitatively evaluate the accuracy of data obtained from liquid-interference surfaces using an intraoral 3D scanner (IOS) integrated with a compressed airflow system, so as to provide clinical proof of accuracy for the application of the compressed airflow system-based scanning head in improving data quality on liquid-interference surfaces. METHODS: The study selected a standard model as the scanning object, adhering to the "YY/T 1818-2022 Dental Science Intraoral Digital Impression Scanner" guidelines, a standard that defined parameters for intraoral scanning. To establish a baseline for accuracy, the ATOS Q 12M scanner, known for its high precision, was used to generate true reference values. These true values served as the benchmark for evaluating the IOS performance. Building on the design of an existing scanner, a new scanning head was developed to integrate with a compressed airflow system. This new design aimed to help the IOS capture high-precision data on surfaces where liquid-interference, such as saliva, might otherwise degrade scanning accuracy. The traditional scanning method, without airflow assistance, was employed as a control group for comparison. The study included five groups in total, one control group and four experimental groups, to investigate the effects of scanning lens obstruction, airflow presence, liquid media, and the use of the new scanning head on scanning process and accuracy. Each group underwent 15 scans, generating ample data for a robust statistical comparison. By evaluating trueness and precision in each group, the study assessed the impact of the compressed airflow system on the accuracy of IOS data collected from liquid-interference surfaces. Additionally, we selected Elite and Primescan scanners as references for numerical accuracy values. RESULTS: The scanning accuracy on liquid-interference surfaces was significantly reduced in terms of both trueness and precision [Trueness: 18.5 (6.5) vs. 38.0 (6.7), P < 0.05; Precision: 19.1 (8.5) vs. 31.7 (15.0), P < 0.05]. The use of the new scanning head assisted by the compressed airflow system significantly improved the scanning accuracy [Trueness: 22.3(7.6) vs. 38.0 (6.7), P < 0.05; Precision: 25.8 (9.6) vs. 31.7 (15.0), P < 0.05]. CONCLUSION The scanning head based on the compressed airflow system can assist in improving the accuracy of data obtained from liquid-interference surfaces by the IOS.
Imaging, Three-Dimensional/methods* ; Humans ; Dental Impression Technique/instrumentation*

To explore the safety and efficacy for radiofrequency ablation of paroxysmal supraventricular tachycardia (PSVT) guided by Carto Univu three-dimensional mapping system.
 Methods: A total of 99 patients with PSVT underwent radiofrequency catheter ablation (RFCA) were assigned to a Carto Univu group (51 patients) and a two-dimensional X-ray group (48 patients) according to the mapping method. The operation time, X-ray exposure time, X-ray exposure dose, dose area product (DAP), operation success rate and complication rate were compared between the two groups.
 Results: The Carto Univu group and the two-dimensional X-ray group were not significant difference in the operation time, the X-ray exposure time of placing catheter, the X-ray DAP of placing catheter, the number of discharge, the discharge power, and the total discharge time (P>0.05). The mapping and ablation time, total exposure time, mapping and ablation DAP and total DAP in the Carto Univu group were significantly lower than those in the two-dimensional X-ray group (P<0.01). In the right accessory pathway cases, the mapping and ablation DAP and the total DAP in the Carto Univu group decreased compared with X-ray group (P<0.05), but it decreased more profound (P<0.01) in the left accessory pathway cases and the dual atrioventricular nodal pathways cases. Seven cases in the Carto Univu group achieved "zero X-ray", including 5 cases of the dual atrioventricular nodal pathways and 2 cases of the left accessory pathway. The immediate success rate for the two groups was 100%. After 3-12 months of follow-up, there was no recurrence in the Carto Univu group but 3 suspected recurrences in the two-dimensional X-ray group. In addition, no complications occurred in the two groups. 
 Conclusion: Carto Univu electroanatomic mapping system can guide PSVT safely and effectively during radiofrequency ablation and reduce radiation exposure to both doctors and patients. It is especially suitable for dual atrioventricular nodal pathways, which may even achieve "zero X-ray". Perhaps Carto Univu will be the first choice for RFCA of dual atrioventricular nodal pathways.
Catheter Ablation ; instrumentation ; methods ; Humans ; Imaging, Three-Dimensional ; instrumentation ; methods ; Operative Time ; Radiation Exposure ; prevention & control ; statistics & numerical data ; Radiography ; statistics & numerical data ; Recurrence ; Tachycardia, Supraventricular ; diagnostic imaging ; surgery ; Treatment Outcome

The purpose of this research was to evaluate the structural stress and deformation of a newly designed onplant miniplate anchorage system compared to a standard anchorage system. A bone block integrated with a novel miniplate and fixation screw system was simulated in a three-dimensional model and subjected to force at different directions. The stress distribution and deformation of the miniplate system and cortical bone were evaluated using the three-dimensional finite element method. The results showed that the stress on the plate system and bone was linearly proportional to the force magnitude and was higher when the force was in a vertical direction (Y-axis). Stress and deformation values of the two screws (screw 1 and 2) were asymmetric when the force was added along Y-axis and was greater in screw 1. The highest deformation value of the screws was 7.5148 μm, much smaller than the limit value. The load was decreased for each single miniscrew, and the ability of the new anchorage system to bear the load was also enhanced to some degree. It was suggested that the newly designed onplant miniplate anchorage system is effective, easily implanted and minimally invasive.
Biomechanical Phenomena ; Bone Plates ; Bone Screws ; Cancellous Bone ; anatomy & histology ; surgery ; Computer Simulation ; Cortical Bone ; anatomy & histology ; surgery ; Finite Element Analysis ; Humans ; Imaging, Three-Dimensional ; methods ; Orthodontic Anchorage Procedures ; instrumentation ; methods ; Stress, Mechanical

The advent of three-dimensional printing (3DP) technology has enabled the creation of a tangible and complex 3D object that goes beyond a simple 3D-shaded visualization on a flat monitor. Since the early 2000s, 3DP machines have been used only in hard tissue applications. Recently developed multi-materials for 3DP have been used extensively for a variety of medical applications, such as personalized surgical planning and guidance, customized implants, biomedical research, and preclinical education. In this review article, we discuss the 3D reconstruction process, touching on medical imaging, and various 3DP systems applicable to medicine. In addition, the 3DP medical applications using multi-materials are introduced, as well as our recent results.
Biomedical Research ; Computer-Aided Design ; Diagnostic Imaging/*instrumentation/*methods ; Humans ; Precision Medicine ; *Printing, Three-Dimensional ; Prostheses and Implants

OBJECTIVE: To evaluate the influence of high-pitch mode (HPM) in dual-source computed tomography (DSCT) on the accuracy of three-dimensional (3D) volumetry for solid pulmonary nodules. MATERIALS AND METHODS: A lung phantom implanted with 45 solid pulmonary nodules (n = 15 for each of 4-mm, 6-mm, and 8-mm in diameter) was scanned twice, first in conventional pitch mode (CPM) and then in HPM using DSCT. The relative percentage volume errors (RPEs) of 3D volumetry were compared between the HPM and CPM. In addition, the intermode volume variability (IVV) of 3D volumetry was calculated. RESULTS: In the measurement of the 6-mm and 8-mm nodules, there was no significant difference in RPE (p > 0.05, respectively) between the CPM and HPM (IVVs of 1.2 +/- 0.9%, and 1.7 +/- 1.5%, respectively). In the measurement of the 4-mm nodules, the mean RPE in the HPM (35.1 +/- 7.4%) was significantly greater (p < 0.01) than that in the CPM (18.4 +/- 5.3%), with an IVV of 13.1 +/- 6.6%. However, the IVVs were in an acceptable range (< 25%), regardless of nodule size. CONCLUSION: The accuracy of 3D volumetry with HPM for solid pulmonary nodule is comparable to that with CPM. However, the use of HPM may adversely affect the accuracy of 3D volumetry for smaller (< 5 mm in diameter) nodule.
Humans ; Imaging, Three-Dimensional/instrumentation/*methods ; Lung/radiography ; Lung Neoplasms/*radiography ; Multiple Pulmonary Nodules/*radiography ; Phantoms, Imaging ; Solitary Pulmonary Nodule/*radiography ; Tomography, X-Ray Computed/instrumentation/*methods

Spinal biomechanics, especially the range of spine motion,has close connection with spinal surgery. The change of the range of motion (ROM) is an important indicator of diseases and injuries of spine, and the essential evaluating standards of effect of surgeries and therapies to spine. The analysis of ROM can be dated to the time of the invention of X-ray and even that before it. With the development of science and technology as well as the optimization of various types of calculation methods, diverse measuring methods have emerged, from imaging methods to non-imaging methods, from two-dimensional to three-dimensional, from measuring directly on the X-ray films to calculating automatically by computer. Analysis of ROM has made great progress, but there are some older methods cannot meet the needs of the times and disappear, some classical methods such as X-ray still have vitality. Combining different methods, three dimensions and more vivo spine research are the trend of analysis of ROM. And more and more researchers began to focus on vivo spine research. In this paper, the advantages and disadvantages of the methods utilized recently are presented through viewing recent literatures, providing reference and help for the movement analysis of spine.
Animals ; Humans ; Imaging, Three-Dimensional ; instrumentation ; methods ; trends ; Radiography ; Spine ; diagnostic imaging

The lack of depth perception and spatial orientation in two-dimensional image of traditional laparoscopy require long-term training of the surgeons. Three-dimensional (3D) laparoscopy provides stereoscopic visions as compared to monocular views in a traditional laparoscopic system. In this review, the authors summarize the clinical application of 3D laparoscopy and its current research progress.
Imaging, Three-Dimensional ; instrumentation ; methods ; Laparoscopy ; methods

OBJECTIVETo explore the value of 3D printing technique in the surgical management and strategy of rehabilitation therapy of acetabular fracture.

METHODSFor a patient with acetabular fracture, the pelvis model was printed preoperatively by 3D printing technique for surgical simulation to determine the optimal position of the screw, measure the screw length, and design the route of screw entry. Laparoscopic assisted internal fixation was performed, and a gradual and systematic rehabilitation plan was carried out after the surgery based on the results of simulation.

RESULTSThe operation was completed successfully with a shortened postoperative recovery time.

CONCLUSIONSThe application of 3D printing allows more accurate and safer surgical management of acetabular fracture to promote postoperative recovery of the patient and lower the medical costs.

Adult ; Bone Screws ; Fracture Fixation, Internal ; methods ; Hip Fractures ; rehabilitation ; Humans ; Imaging, Three-Dimensional ; Male ; Postoperative Period ; Printing, Three-Dimensional ; Rehabilitation ; instrumentation ; methods