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1.
Article in Chinese | WPRIM | ID: wpr-734408

ABSTRACT

Objective To investigate the feasibility and primary clinical outcomes of a kind of independent research and development customized 3D printed external fixator in the treatment of tibial fracture.Methods Data of 7 tibial fracture patients who were treated using computer-assisted reduction and 3D printing technique including a new kind of customized external fixator with automatical reduction function from December 2013 to November 2015 were retrospectively analyzed.There were 5 males and 2 females in this cohort.The age of the patients ranged from 25 to 49 years old,with an average age of 38.1 years old.The procedure was as follows.At first,two or three pins were placed separately into the distal and proximal tibia away from fracture site.Then,the CT scanning was performed on the fractured tibia.According to the CT scanning data,the external fixator was designed by computer software and manufactured by the 3D printing technique.The reduction of tibial fracture was achieved automatically after the 3D printed external fixator was connected to the inserted pins.Finally,the accuracy of reduction was assessed by postoperative X-ray image.During the different fracture healing course,the stress environment could be dynamically adjusted by screwing or unscrewing the nuts to fulfill rigid fixation,compression fixation or elastic fixation for the bone healing.Results All the 7 cases had obtained successful reduction by only one time operation with the 3D printed external fixators.The average lateral angulation was 1.42°± 1.13°,and the average anteroposterior angulation was 1.65°± 1.36°,while the average lateral displacement was 1.38± 1.44 mm,and the average anteroposterior displacement was 1.83± 1.30 mm,which were measured from postoperative X-ray image.The individual durations of the operation were 9 min,8 min,9 min,1.5 min,1.4 min,1.4 min and 2.4 min,respectively.All fractures had achieved bony union in 19-25 weeks after operation,with an average time of 21.4±1.6 weeks.All patients were followed up for 6 months when removal of the external fixator,and no refracture occurred.Conclusion The customized 3D printed external fixator has the function of automatical reduction.In addition,it can provide three kinds of fixation modes,which are rigid fixation,compression fixation and elastic fixation.It has the advantages of simple operation,accurate reduction,reasonable fixation,etc.

2.
Article in Chinese | WPRIM | ID: wpr-771122

ABSTRACT

Aiming at comparing the pre-operative and post-operative gait characteristics and therefore establishing post-operative rehabilitation guidance for patients with end-stage knee osteoarthritis (KOA) merged with varus deformity, this study captured the level walking and sit-to-stand trials of 9 patients with 3-dimensional motion analysis system and after which musculoskeletal multi-body dynamic analysis was conducted. The study indicated that the average range of motion (ROM) of the proposed-surgical knee was 24.4°-57.6° and that of the non-surgical knee was 22.5°-71.5°. The knee ROM of control group during level walking was 7.2°-62.4°. When the unilateral KOA patients stood up from chair to complete the sit-to-stand movement, the ground reaction forces (GRFs) symmetry was 0.72-0.85, which means that the non-surgical limb bear the majority of body weight. The GRFs of the bilateral KOA patients were smallest during the sit-to-stand movement. The strategy that the non-surgical limb dominates in loading bearing taken by the unilateral KOA patients to cover most post-operative daily activities could increase the risk of KOA among non-surgical side joints as a result of long-term excessive loading-bearing. The study, on kinematics and biomechanical characteristics of patients with KOA merged with varus deformity, could help to understand the pathogenesis of KOA merged with varus deformity from the perspective of biomechanics and to provide strong clinic guidance for the pre-operative evaluation, prevention and post-operative recovery for patients.

3.
Article in Chinese | WPRIM | ID: wpr-266723

ABSTRACT

Focusing on the poor mechanical strength of porous bioceramics bone scaffold, and taking into account of the good mechanical properties of biodegradable magnesium alloy, we proposed a novel method to fabricate magnesium alloy/bioceramics composite bone scaffold with stereolithography double channels. Firstly, a scaffold structure without mutually connected double channels was designed. Then, an optimized bioceramics scaffold was fabricated according to stereolithography and gel-casing. Molten AZ31 magnesium alloy was perfused into the secondary channel of scaffold by low-pressure casting, and magnesium alloy/bioceramics composite bone scaffold was obtained when magnesium alloy was solidified. The compression test showed that the strength of bioceramics scaffold with only one channel and without magnesium alloy was (9.76 ± 0.64) MPa, while the strength of magnesium alloy/bioceramics composite scaffold with double channels was (17.25 ± 0.88) MPa. It can be concluded that the magnesium alloy/bioceramics composite is obviously able to improve the scaffold strength.


Subject(s)
Alloys , Biomechanical Phenomena , Bone and Bones , Ceramics , Humans , Magnesium , Materials Testing , Porosity , Tissue Scaffolds
4.
Article in Chinese | WPRIM | ID: wpr-484984

ABSTRACT

BACKGROUND:With significantly individual differences in the anatomy of the knee joint, traditional total knee replacement is difficult to accurately predict the position of locating limb alignment, size of the prosthesis and osteotomy amount of patients during operation. OBJECTIVE:To investigate the clinical effect of total knee replacement based on the assistance of medical image reconstruction, computer-aided design technology and 3D-printing personalized surgical navigation template. METHODS:Medical image data of patients were col ected using CT or magnetic resonance scanning equipment. The three-dimensional reconstruction of the bone was conducted by two-dimensional medical image processing technology. The navigation template was designed by computer-aided design technology. The personalized surgical navigation templates were produced by 3D printing technology, and the clinical total knee replacement was conducted. The postoperative results were evaluated using imageology. RESULTS AND CONCLUSION:Arigin 3D Pro (Arigin Medical Co., Ltd.) can accurately reconstruct a three-dimensional model of the lower limb bones. The three-dimensional design software Arigin Surgical Templating by their independent research and development can precisely pinpoint related lower limb axis, including limb alignment, rotation axis of the femur and osteotomy reference point. The personalized navigation template we researched and produced for knee surgery fitted tightly with femoral condyle and tibial plateau bone anatomy during operation, without significant movement. The deviation of patients’ limb alignment was less than 3° after total knee replacement.

5.
Article in Chinese | WPRIM | ID: wpr-444736

ABSTRACT

BACKGROUND:In recent years, many manufacturing techniques have been recently developed for soft tissue engineering scaffolds. Especialy additive manufacturing with a unique material accumulated forming principle can be feasible and reliable to manufacture the highly precise scaffolds with gradient structures and multi-materials for large soft tissue defect repairing. OBJECTIVE:To summarize scaffolds manufacturing technologies in the soft tissue engineering applications developed in recent years and to predict the direction of development. METHODS: A retrieval was performed for the literature about the manufacturing methods of soft tissue scaffolds using key words of “additive manufacturing, microfabrication, vascular tissue engineering, muscle tissue engineering, cartilage tissue engineering, stereolithography, 3D printing, biodegradable hydrogel” in English and Chinese, which were published between January 2010 and September 2013 in PubMed Database and China National Knowledge Infrastructure (CNKI) Database. RESULTS AND CONCLUSION:For large soft tissue defects repairing, structure design of the scaffolds has been shifted from a simple planar structure to a more complex three-dimensional structure, and integration of scaffold structure, materials and cels, and growth factors during the manufacturing procedure can be used to obtain the resolution of vascularization. Additive manufacturings become one of the most promising approaches for the ideal soft tissue scaffolds with gradient and complex structure and multi-materials. In particular, the hydrogel/cellcomposite scaffolds fabrication, a hot but promising approach to develop the soft tissue engineering wil be made progress by the accurate principles and processes of the hydrogel additive manufacturing combined with the introduction of living cels and growth factors.

6.
Article in Chinese | WPRIM | ID: wpr-259921

ABSTRACT

A new system of blood flow block for control of bleeding in abdominal operation is composed of an abdominal magnetic blocking unit, an abdominal external electromagnet unit and other non-magnetic operation instrument. The abdominal external electromagnetic unit is placed in advance in the operation bed. The abdominal magnetic blocking unit can be placed directly on the ventral of the large vessels when need to blocking the abdominal large vessels during the operation. According to the non-contact suction characteristics of magnetic materials, the two magnetic units will attract each other and compression the vessels. Using this system for vascular occlusion does not need clear exposure and without separating vessel. There is the advantage of rapid, accurate and reliable for the system.


Subject(s)
Abdomen , Blood Loss, Surgical , Electromagnetic Phenomena , Equipment Design , Surgical Equipment
7.
Article in Chinese | WPRIM | ID: wpr-359144

ABSTRACT

Referring to the anatomical characterization of natural spongy bone and channel network in cortical bone, we designed a new pattern of biomimetic impalnt with preset channel for blood vessel inserting to treat early femoral head necrosis. The surgical ptrocedure was simulated by CAD model. Ceramic stereolithography was applied to fabricate the green part. Other process, such as dehydration, rinsing, drying and sintering, were taken successively. The final ceramic part kept identical with the engineered part either in the shape or in the internal structure. No deformation or crack happened. Pore size, interconnected pore size, porosity and interconnected porosity of ceramic part could satisfy cellular grouth. Spectrum analysis showed that no phase transition or chemical reaction happened during fabrication process. The biocompatibility of the final part kept the same with original during beta-TCP powder. The compressive strength was 23.54 MPa, close to natural spongy bone. It is an ideal implant to treat early femoral head necroseis because it makes preimplantation of cells and biological factors, blood velssel inserting, early establishment of blood supply possible. At the same time, it could provide enough mechanical support to prevent collapse of femoral head. It could provide a wide clinical foreground.


Subject(s)
Biocompatible Materials , Chemistry , Bone Substitutes , Chemistry , Calcium Phosphates , Chemistry , Computer-Aided Design , Femur Head Necrosis , Therapeutics , Humans , Porosity , Prostheses and Implants , Tissue Engineering , Tissue Scaffolds , Chemistry
8.
Article in Chinese | WPRIM | ID: wpr-331393

ABSTRACT

A rotating perfusion bioreactor system has recently been developed in our laboratory to produce 3D dynamic culture condition, and the critical-sized scaffolds with interconnected microchennels were fabricated. Gas exchange occurs by semipermeable membrane covered on each side of bioreactor and gas-permeable peristaltic pump tube. Rotation and perfusion of culture media through large scaffolds enhance well mixing and mass transport of oxygen and nutrients in the bioreactor. Osteoblastic cells attached to microchennels are exposed to a low fluid flow-induced shear stress level. This bioreactor system overcomes several defects exited in static culture condition, improves the culture environment, facilitates osteoblast proliferation, differntiation, significant matrix production and mineralization, and the controllability of culture process is enhanced. Large scaffolds/osteoblast constructs were cultured in the bioreactor system for 14 days. Osteoblastic cells attached to microchannels of scaffolds were observed under scanning electron microscope (SEM). The results indicated that cells grew extensively in the microchennels of large scaffolds.


Subject(s)
Animals , Animals, Newborn , Bioreactors , Cell Culture Techniques , Methods , Cell Differentiation , Osteoblasts , Cell Biology , Rabbits , Skull , Cell Biology , Tissue Engineering , Methods , Tissue Scaffolds
9.
Article in Chinese | WPRIM | ID: wpr-320484

ABSTRACT

It is the critical technology for bone tissue engineering to fabricate scaffolds, especially to fabricate the internal microchannel of scaffolds. Utilizing stereolithography rapid prototyping indirect fabrication approach, suitable size microchannel structure scaffolds with orientation, branching, and interconnectivity under control was manufactured. Observation under light microscope showed that the arrange of microchannel size was 200-600 microm, the orientation and branching were accorded with designed structure, and all the microchannels were completely interconnected. Scaffolds seeded with osteoblast cells were put into 6-well plate and rotating 3D dynamic culture system which was developed in our lab. The morphology of osteoblasts and the development on the surface and internal microchannel of scaffolds were observed under scanning electron microscope (SEM). The results indicated that the dynamic culture permited an even distribution of cells across the surface of scaffolds, besides, a few cells grew into the lumen of microchannels.


Subject(s)
Animals , Bone Substitutes , Cell Culture Techniques , Methods , Cells, Cultured , Osteoblasts , Cell Biology , Rabbits , Surface Properties , Tissue Engineering
10.
Article in Chinese | WPRIM | ID: wpr-597639

ABSTRACT

BACKGROUND:At present, there are several limb-preserving methods,such as xenogenic bone joint replacement, artificial metal prothesis replacement and inactivation and replantation of tumor bone segment, etc.Each method has its advantages and disadvantages. In addition, mismatch of xenogenic and autogeneic joints and articular cartilage necrosis in the late stage, which affects joint function, are two important problems for large frozen bone-joint allograft at ultra-low temperature in repair of bone defect following bone tumor resections in extremities.OBJECTIVE:To evaluate a method to obtain outline information on the cartilage surface through spiral CT scanning data, so as to lay foundation for study on individualized artifical semi-knee joint based on rapid prototyping (RP) technique.DESIGN: Open experiment.SETTING: First Department of Trauma, Urumqi General Hospital of Lanzhou Military Area Command of Chinese PLA.MATERIALS: This experiment was carried out at Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University of Chinese PLA, and Institute of Advanced Manufacturing, Xi'an Jiaotong University from September 2001 to May 2003. CT scanning subject was a 25-year-old healthy male volunteer.METHODS:Distal femur was performed 1 mm in thickness scanning with Picker 6 000 spiral CT. Three-dimensional volume reconstruction was conducted at the Voxel Q Image workstation on Picker 6000 CT, then, two-dimensional tomography image of reconstruction data were downloaded with spacing of 0.1 mm. Data format converter software was self-developed. The downloaded image was treated through smoothing, de-noise and so on.Vector data of two-dimensional borderline outline of tomography image was calculated and input into Surfacer 9.0 software (American Imageware company) for vectorial three-dimensional reconstruction. According to recognition of articular cartilage outline and request of prothesis design, the threedimensional images of interested articular cartilage surface outline were extracted and used in the computer-aided design for individualized artificial semi-knee joint.MAIN OUTCOME MEASURES:Vector converting of CT image and vector image of three-dimensional reconstruction of femoral condyle.RESULTS:Vector converting of CT image dafa had been come true using self-developed medical image vector converter software. Three-dimensional solid model of individualized femoral condyle was constructed with Surfacer9.0 three-dimensional processing software and edited according to design request. Three-dimensional model of articular cartilage requested by artifical semi-knee joint prothesis was extracted for computer-aided design. The constructed articular surface outline could be treated further to complete computer-aided design of artificial semi-knee joint prothesis; The file format was .stl, which could be recognized by RP software and used in engineering.CONCLUSION:Vector reconstruction of articular cartilage outline is performed based on spiral CT data that can obtain precise three-dimensional solid model of articular cartilage outline. The three-dimensional model can be edited, which lays foundation for computer-aided design and RP manufacturing of artificial semi-knee joint prothesis compounded with large segment xenogenic bone; It is easy and practicable in vector converting of medical image information with this method, and it also has good application prospect in biomanufacturing field in orthopaedic and oral maxillofacial surgery.

11.
Chinese Journal of Surgery ; (12): 932-935, 2002.
Article in Chinese | WPRIM | ID: wpr-257749

ABSTRACT

<p><b>OBJECTIVES</b>To construct new type of bone graft material by combining calcium phosphate cement (CPC) with bone morphogenetic protein (BMP), and then to detect its osteogenic activity.</p><p><b>METHODS</b>The surface of CPC and CPC/BMP composite were observed by scanning electron microscope (SEM). CPC and CPC/BMP pellets were separately implanted into the thigh muscle pouches of mice. Samples obtained at different times were tested by histological analysis, SEM, organic substance detection, and alkaline phosphatase (ALP) measurement to observe the induced ectopic bone formation.</p><p><b>RESULTS</b>Under SEM, the CPC and CPC/BMP composite was found to consist primarily of platy crystals, granular crystals and some small rod-like crystals with micropores about 10-50 microm in size. BMP about 1-5 microm in size was seen like micro globules distributing evenly in the micropores. Newly formed cartilage or bone was not found in the CPC group. In the CPC/BMP group, mesenchymal cells were proliferated and abundant cartilage was found in one week. Woven bone appeared at 2 weeks. New bone formation increased with bone marrow at 4 weeks. At 8 weeks, the implanted CPC/BMP became heterogeneous and a lot of collapsed granules were observed. At the end of 16 weeks, mature lamellar bone appeared and the volume of the implanted CPC/BMP became smaller. One week after implantation, the ALP increased evidently in the CPC/BMP groups and reached the highest level at the 4th week, which was about 168 U/L. The content of organic substance in specimens increased from 22% to 39% by the end of the 16th week, showing the continuous calcification and formation of new bone. SEM also showed that the CPC/BMP composite had good potentiality of ectopic bone induction, and the new bone formed accompanied by the slow degradation of the material.</p><p><b>CONCLUSION</b>The results of this study suggested that the CPC/BMP composite could be used as material for bone graft substitute.</p>


Subject(s)
Animals , Bone Cements , Bone Morphogenetic Proteins , Pharmacology , Bone Substitutes , Pharmacology , Calcium Phosphates , Male , Materials Testing , Mice , Mice, Inbred Strains , Osteogenesis , Prosthesis Implantation
12.
Article in Chinese | WPRIM | ID: wpr-433901

ABSTRACT

Purpose To study the main points of the diagnosis and differential diagnosis of the lymphadenitis in CSD. Methods Expression of CD45, CD3 and CD68 were evaluated immunohistochemically (S-P method). Results Five cases of microabscess in early stage and 21 cases of microabscess-granuloma were found. The histologic features were the formation of microabscess and granuloma. The early microabscess in the lymphnodes were surounded by B lymphocytes (CD20+) and macrophages (CD68+). The typial microabscess granuloma were surrounded by epitheloid cells (CD68+) and CD3 positive T lymphocytes. Conclusion The main characteristic of the lymphadenitis of cat scratch disease is the formation of granuloma with microabscess. The immumohistochemical markers are useful to distinguish the proliferative cell types. This lesion may result from bacterial infection which induces the cell immune reaction.

13.
Article in Chinese | WPRIM | ID: wpr-670856

ABSTRACT

Objective:To investigate the stress distribution of the edentulous maxilla with unilateral maxillary defect after implant rehabilitation under occlusal loads.Methods:Three dimensional finite element model of the edentulous maxilla with unilateral maxillary defect was build.The stress distribution of the edentulous maxilla under occlusal loads with computer simulated implant rehabilitation was investigated.Results:Regardless of load manner,the stress of the bone around 1 were high when just healthy side implanted,but the stress reduced after implantantion in health side combined with the implantation in zygoma in defect side.Conclusion:Implantation in health side combined with that in zygoma in defect side can reduce the stress of the bone around the implant.

14.
Article in Chinese | WPRIM | ID: wpr-670636

ABSTRACT

Objective: To enable an artificial mandible substitute to be with individualized shape in the individual patient. Methods: Rapid prototyping and surface imitating were used as the primary technology in the individualized design and manufacturing of the artificial mandible substitute. Results: The shape and size of the manufactured artificial mandibe were almost the same to those of the original natural one. Conclusion: Rapid prototyping may be used in individualized bone substitute preparation.

15.
Article in Chinese | WPRIM | ID: wpr-670568

ABSTRACT

Objective: To enable an artificial mandible substitute to be mostly suitable for mandibular reconstructon in individual patients. Methods: Use rapid prototypinlg and surface imitating as the primary technology for individualized design and manufacturing of the artificial mandible substitute. Results: An individualized artificial mandible substitute was designed and prepared. Conclusion: Rapid prototyping is feasible in individualized bone substitute preparation.

16.
Article in Chinese | WPRIM | ID: wpr-537814

ABSTRACT

objective: To study the stress distribution of abutment dentin of mandibular complete overdenture based on post core abutment(COBPA). Methods: 3 D FEM was employed to investigate the stress distribution of abutment dentin of mandibular COBPA and natural abutment(NA) on standard model, the data were compared. Results: In the same loading condition, stress concentration was observed at the root end area of dentin in both COBPA and NA. When post core was applied decreased stress distribution area and increased stress value were found aroud tooth neck, decreased stress concentration was found at root end. Conclusion: In COBPA and NA the stress may be transferred to the root end along the axis. Apart from retention, post core can transfer and buffer the stress, change the way of stress transfer, and may result in cervical fracture.

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