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Objective To explore the short-term efficacy of digitally-assisted traditional Chinese medicine manual reduction combined with 3D printed splint in the treatment of AO type-A distal radius fractures, and explore the quantification of traditional Chinese medicine manual reduction and personalized improvement of splinting. Methods The clinical data of 50 patients with AO type-A distal radius fractures, who received treatment at the outpatient department of Cangzhou Integrated Traditional Chinese and Western Medicine Hospital in Hebei Province, were retrospective analyzed. The patient cohort included 22 females and 28 males, with ages ranging from 25 to 75 years old. Among them, 27 cases presented with distal radius fractures on the left side, and 24 cases on the right side. The patients were categorized into two groups: treatment group (n=25) and control group(n=25). There were 13 males and 12 females in the treatment group, with an average age of (56.2±5.5) years old. Treatment approach for this group involved several steps. Initially, Mimics Research software was used to conduct comprehensive analysis of complete CT data from the affected limb, resulting in the creation of a three-dimensional model. Subsequently, 3D models of the bones and skin contours, stored as STL format files, were imported into the Materialise Magics 23.0 software for model processing and repair. This facilitated the simulation of reduction and recording of displacement data, effectively generating a "digital prescription" to guide and quantify traditional Chinese medicine manipulation procedures. Finally, a personalized 3D printed splint was applied for fixation treatment. There were 15 males and 10 females in the control group, with an average age of (53.32±5.28) years old. These patients were treated with manualreduction combined with traditional splinting. The clinical efficacy of the two groups was assessed in terms of fracture reduction quality, fracture healing time, Gartland-Werley wrist joint score and X-ray parameters (palminclination angle, ulnar deviation angle, radius height) at 6 weeks post-operatively. Results The treatment group exhibited a shorter duration for achieving clinical healing compared to the control group (P<0.05). Six weeks post-operatively, the treatment group demonstrated higher wrist joint function scores, and a higher proportion of excellent and good outcomes than the control group(P<0.05). The treatment group was superior to the control group in terms of imaging parameters 6 weeks post-operatively (P<0.05). Conclusion By quantifying skin contours through digital simulation prescription reduction, a personalized 3D printed splint is developed to effectively stabilize fractures, enhancing localized fixation while ensuring greater adherence, stability, and comfort. This innovative approach offers personalized treatment for AO type-A distal radius fractures and presents a novel, precise treatment strategy for consideration.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , East Asian People , Printing, Three-Dimensional , Retrospective Studies , Splints , Wrist Fractures/therapy , Medicine, Chinese Traditional/methods , Therapy, Computer-Assisted/methods , Manipulation, Orthopedic/methods , Tomography, X-Ray Computed , Precision Medicine/methodsABSTRACT
BACKGROUND: Different bone materials have different properties. Therefore, to simplify the model and improve the analysis efficiency in biomechanical analysis, many scholars have adopted different assignment methods to the bone model in the biomechanical simulation research. The distribution of material properties will have a great influence on the results of biomechanical analysis. OBJECTIVE: Three kinds of finite element models of the femur were established by different material attribute assignment methods, and the finite element simulation analysis was carried out to explore the influence of different material assignment methods on the biomechanical simulation analysis of femur finite element. METHODS: Volunteer femur CT scanning data were collected and imported into Mimics medical image processing software in DICOM format to reconstruct the femur model. Three different material attributes were assigned to the models, including uniform material assignment, skin cancellous bone assignment and gray scale assignment. The models were imported into finite element analysis Abaqus 6.14 software to set the same load and boundary conditions for stress and displacement analysis. RESULTS AND CONCLUSION: (1) The stress values of the three kinds of models differed slightly and were all in a reasonable range. (2) Whereas, the maximum stress of homogeneous assigned model and the model assigned according to cortical-cancellous bone assembly model mainly distributed in the diaphysis region, while the maximum stress distributed in the femoral neck region for the gray value assigned model. (3) The displacement value of cortical-cancellous bone assigned model was essentially in agreement with the gray value assigned model. The homogeneous assigned femoral model possessed the minimum displacement value and the value was about 40% different from the other two models. (4) The grayscale method can better reflect the biomechanical characteristics of human femur, so as to more accurately simulate the real biomechanical characteristics of real femur, which also provides an important theoretical basis for the finite element simulation modeling of orthopedic biomechanics.
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BACKGROUND: It is reported that the hip-conserving effect of osteonecrosis of femoral head is closely related to the retention of lateral column. The classification of China-Japan Friendship Hospital is based on the three-column structure, and the prediction accuracy of femoral head collapse is high. OBJECTIVE: To establish a three-dimensional finite element model for China-Japan Friendship Hospital classification of femoral head necrosis, and to analyze the mechanical changes of fibula implantation in each classification by finite element method, and to explore the significance of lateral column retention in hip preservation, so as to provide a basis for precise prediction of collapse of the classification. METHODS: Three groups of 11 kinds of three-dimensional finite element models of normal femoral head, China-Japan Friendship Hospital type femoral head necrosis (type M, type C, type L1, type L2, type L3) and fibula implantation were established. The finite element analysis was carried out by ANSYS software. The maximum stress, maximum displacement and load transfer mode of proximal femur were observed in each group. RESULTS AND CONCLUSION: (1) In the necrosis group, the strain was the largest, and the displacement was different due to the different types of necrosis. The displacement changes were as follows: Type M < type C < type L1 = type L2 < type L3. The displacement recovery of fibula implantation group was lower than that of the normal group, and the displacement recovery was different due to the different necrosis types. The displacement changes were as follows: Type M < type C < type L1 < type L2 < type L3. The reduction range of the displacement of the repaired necrotic femoral head gradually decreased from the lateral column to the medial column, which was lower than the maximum displacement of the normal femoral head. (2) The peak value of the stress nephogram of the loading area of the femoral head after necrosis was higher than that of the normal group. The peak value of necrotic type M was nearly normal. The peak value of necrotic type C was 74.5% higher than that of the normal group, and the peak value of necrotic type L was more than 100% higher than that of the normal group. The peak value of necrotic type M after operation was not only 14.2% lower than that before operation, but also was lower than that of the normal group. The peak value of necrotic type C after operation was 5.3% lower than that before operation, but higher than that of normal group. The peak value of necrosis type L after operation was lower than that before operation, but significantly higher than the normal level. (3) The load transfer in the normal femoral head was continuous. The conduction path was from the lateral column of the femoral head to the femoral moment. In the necrosis group, the internal load transfer of types M and C femoral head was continuous, and the conduction of type M was basically consistent with normal. The stress of type C conduction to femoral moment was reduced. The load transfer of L1, L2 and L3 type femoral head was interrupted. The stress changed in cliff type, and was unable to transmit to femoral moment, resulting in stress concentration in load area of the femoral head. A certain effective load transfer mode was reconstructed in the femoral head of the fibula implantation group, and the stress concentration at the femoral moment occurred in all types of conduction. Part of the load was transferred to the femoral moment through fibula, and the normal load transfer mode was partially restored. (4) China-Japan Friendship Hospital type fibula placement can prevent the collapse of the femoral head to a certain extent. The location and size of the necrosis area are very important. The closer the necrosis is to the lateral column, the easier it is to collapse and the more difficult it is to repair. The retention of the lateral column is an important factor for accurate prediction of the collapse of the femoral head.
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BACKGROUND: The biomechanical characteristics of knee meniscus have been studied extensively at home and abroad, but most of them focus on the knee flexion motion. The finite element analysis of biomechanics of knee joint meniscus under the complete gait cycle is not yet perfect. OBJECTIVE: To understand the mechanism of biomechanical changes after meniscus injury in the complete gait cycle by comparing the lateral meniscus tear model with the healthy meniscus model. METHODS: Based on the CT scan data of healthy adult knee joints, a finite element model of healthy knee joint including tibia, meniscus and articular cartilage was established. The lateral meniscus tear of knee joint was constructed based on the healthy model. The biomechanical mechanism of lateral meniscus tear in the knee during complete gait cycle was explored and compared with the healthy knee model. RESULTS AND CONCLUSION: (1) The instantaneous stress variation of the tibia cartilage during the complete gait cycle was consistent in both models. The tibial cartilage stress at each instant in the meniscus tear model was higher than that of the healthy meniscus model. The maximum stress values of tibia cartilage in the meniscus tear model and the healthy meniscus model was 30 and 20.5 MPa. (2) The instantaneous stress variation of the meniscus during the complete gait cycle was consistent in both models. The meniscus stress at each instant in the meniscus tear model was higher than that of the healthy meniscus model. The maximum stress values of meniscus in the meniscus tear model and the healthy meniscus model was 69.8 and 41.3 MPa. (3) In the first 60% of the gait cycle, the maximum stress distribution of the tibia cartilage in the meniscus tear model was much larger than that in the healthy model, and as the gait cycle grew, the contact range gradually spread to the outer edge of the cartilage. After 60% of the gait cycle, the stress on the tibia cartilage was small, and the distribution range of the maximum stress was also small. (4) The stress distribution of the healthy medial meniscus was basically the same in the two models, while the maximum stress distribution of the torn outer meniscus was wider than that of the healthy medial meniscus. A more severe stress concentration phenomenon occurred around the crack, and with the gait cycle, the stress concentration area gradually shifted toward the crack near the anterior corner of the meniscus. (5) These results suggest that the meniscus is an important load-bearing component in human knee joint. From the perspective of biomechanics, the hazard of the meniscus injury on the human knee joint can be observed more intuitively.
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Orthopedic 3D printed surgical navigational template is an instrument that is prepared by 3D reconstruction based on preoperative radiological data of the patient using computer-aided design (CAD) and 3D printing techniques. The 3D printed navigational template allows accurate intra-operative assessment of the relative spatial distance, angular relationship, direction and depth. The application of 3D printed navigational template technique in orthopedics surgeries achieves the conversion of preoperative planning from 2/3D graphics to 3D models, and provides a new method for individualized and precise treatment. Herein we review the evolution, clinical application, and basic classification of 3D printed navigation template technique, analyze its advantages and disadvantages, and discuss the current problems and the future development of this technique.
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Humans , Computer-Aided Design , Orthopedic Procedures , Printing, Three-DimensionalABSTRACT
BACKGROUND:As lumbar spine biomechanics research is unceasingly thorough and the constant development of related fusion and dynamic fixation device, the spine fusion technique which is represented by artificial disc replacement is a new choice to the spine surgeons. Therefore, it is particularly important to design reasonable artificial intervertebral disc. OBJECTIVE:To establish the finite element model of the new artificial disc replacement of the lumbar motion segment for further biomechanical study. METHODS:The L3-4 thin-section CT images of a healthy male volunteer was selected, combined with human anatomy data and applied the reverse engineering technology to rebuild the lumbar spine model with medical image software Mimics and tool software Geomagic Studio. The three-dimensional model of the silicone artificial disc was converted into a finite element model through software ANSYS12.0. RESULTS AND CONCLUSION:Through CT scanning, digital image processing and computer-aided design, the three-dimensional model of the lumbar motion segment and the finite element model of artificial disc replacement were successful y established. The finite element model contained 691 085 units and 1 008 913 nodes which could be applied constraint and load and could be used for spinal biomechanics and the further research of the new artificial intervertebral disc.
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BACKGROUND:Spine is relatively complex in structure, shape, material properties, and load bearing. The traditional biomechanical method cannot solve these problems. OBJECTIVE:To investigate the stress distribution of intervertebral disc, zygapophysial joints and vertebral body of degenerative scoliosis, and to provide accordance to the biomechanical mechanism of degenerative scoliosis occurrence and development. METHODS:Based on the successive CT images of spinal column from T12 to superior segment of S1 of degenerative scoliosis patients, the special material properties were attributed to the model to form the integrated and effective three-dimensional finite element model of degenerative scoliosis. The model was loaded on the anteflexion, extension, left lateral bending, right lateral bending, left rotation and right rotation conditons. Then the spinal activity and the stress distribution of intervertebral disc, vertebral body and articular cartilage of zygapophysial joints were calculated and analyzed. RESULTS AND CONCLUSION:The spinal activities of degenerative scoliosis finite element model were less than those of common lumbar spine. The stress distribution of intervertebral disc was inclined to the verge of it and the greatest stress was appeared on the extension motion. The apex of scoliosis was the place of stress concentration and the obvious stress concentration of articular cartilage of zygapophysial joints was appeared on the rotation motion, then fol owed by the extension motion, especial y that of articular cartilage of zygapophysial joints on the apex of scoliosis. Stress concentration is easily appeared on the apex of scoliosis, and the extension and rotation motion can aggravate the development of degenerative scoliosis.
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BACKGROUND:Mechanical experiment of finite element numerical simulation is the effective method to research the biomechanical structure of human body. OBJECTIVE:To establish the three-dimensional finite element model of a normal 6-year-old child’s humerus. METHODS:CT images of a 6-year-old child volunteer were imported to the Mimics 10.01 software. The threshold segmentation method was used to rebuild the humerus three-dimensional model. The surface optimization treatment and surface patches dicision were performed on the surface of the model with Geomagic Studio 12.0 software. Then the mesh generation was completed in the software TrueGrid. Final y, the material properties were set and the finite element model was completed. The boundary conditions and constrains were exerted to simulate the three-point-bending test of humeurs. After the simulation, the results were outputted. RESULTS AND CONCLUSION:The humerus finite element model included 3 024 nodes and 18 758 nodes-hexahedron elements. The 0.01 m/s and 3 m/s dynamic loads were loaded respectively, then the central humerus fracture occurred and the load-displacement curve was close to the cadaver test results. The simulation results show that the simulation results of children humerus finite element model are close to the cadaver’s test, and the finite element simulation method can simulate the physical properties of the human skeleton very wel .
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BACKGROUND:The finite element model has been developed from two-dimensional model to three-dimensional model, from linear model to nonlinear model. As the advantage of this method in the analysis of mechanical characteristics of the irregular objects, the finite element model has been widely used in the research of orthopedic biomechanics, especial y in the research of hip joint. OBJECTIVE:To analyze the stress state of human femur with finite element analysis method and to investigate a method that can rapidly construct femoral finite element model and precisely analyze the biomechanics. METHODS:Normal male femur was used as specimen for CT scan to obtain cross-sectional images of femur in each slice. Three-dimensional reconstruction was performed with DICOM data and MIMICS software, then the femoral three-dimensional finite element model was established with the finite element analysis ABQUS 6.8 software, and the stress distribution of the model was analyzed under loading condition. RESULTS AND CONCLUSION:Based on DICOM data, three-dimensional finite element model of femur was constructed more quickly and precisely. The models were divided into 38 636 nodes and 201 422 units. The model included the parts of cortical and cancel ous bone. The biomechanical test results were accorded with the previous results, so the model could objectively reflect the real femur shape and biomechanical behavior with high precision. The Mimics software provided a simpler and effective method for the construction of femur model and improved the efficiency of modeling, and the three-dimensional finite element model based on DICOM data was accurate in shape and can be used for the normal research on biomechanical behavior of femur. The stress distribution analyzed with ABQUS 6.8 software is consistent with the clinical observation.