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BACKGROUND:On CT reconstruction of three-dimensional (3D) model, fracture virtual reduction and internal fixation cannot be achieved, and reasonable operation scheme cannot be formulated. Digital design can fuly meet the needs of clinical orthopedics physicians. Standard parts database can provide the possibility to choose the ideal internal fixation. 3D printing makes the reasonable operation scheme accurate in clinical implementation. OBJECTIVE:To discuss the feasibility, accuracy and minimal invasion of internal fixation in treatment of the distal femoral fracture with digital design of standard parts database by 3D printing. METHODS: (1) Nine adult lower extremity specimens were selected to take continuously thin-layer CT scanning. After Dicom images were imported into the mimics software, the model was established. According to the AO classification, they were classified into A1-3, B1-3 and C1-3 types of distal femoral fracture by virtual design. Internal fixation with plate and screw formed standard parts database virtualy. It was printed out the pilot hole of the navigation module design by three-dimensional printing forming technique. Plate and screw were inserted assisted by the module. X-ray and CT scan were taken postoperatively to access the position. (2) 30 patients with distal femoral fracture were subjected to above fixation. The operation time, intraoperative blood loss and postoperative drainage were recorded. Imaging and curative effects were evaluated during folow-up. RESULTS AND CONCLUSION: (1) Nine samples underwent X-ray and CT scan. 3D reconstruction results revealed plate position, screw entry point, nail direction, length and diameter were consistent with presetting data in Mimics software. The navigation models were designed to fit the lateral bony structure of distal femur. There were good fitting degree, good card position and good stability when the navigation was applied. It could guide plant and screw implantation. (2) In 30 cases, the operation time was (104.63±26.12) minutes, intraoperative blood loss was (121.74±11.49) mL, and postoperative drainage volume was (30.29±6.38) mL. Al patients were folowed up. According to Schagzker criterion, the efficiency of 22 cases was excelent, 6 cases good and 2 cases average, and the excelent and good rate was 93%. The parameters of length, diameter, orientation and angle were consistent with that preoperatively. (3) Internal fixation formed by standard parts database assisted by 3D printing navigation model has advantages of high accuracy, short process, lessened blood loss, high safety, less complications, and precise fixation. Digital design of standard parts database via3D printing navigation module is expected to achieve implant navigation and application.
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BACKGROUND:Preliminary experiments have performed three-dimensional (3D) reconstruction of proximal tibial fractures, digital steel plate design, the establishmentof the proximal tibia plate standard parts library and the operation simulation of 3D printing. OBJECTIVE:To explore feasibility and accuracy of standard parts library plates and screws in the proximal tibial fracture internal fixation navigation in digital design combined with 3D printing model on the basis of preliminary studies. METHODS:Dicom format images of continuous thin layer CT scanning were colected in 20 cases of proximal tibial fractures, and uploaded in Mimics software for 3D reconstruction and fracture reduction. Plate and screw selected from standard part library wereusedfor virtual fixation. Navigation module with screw channel was designed. 3D printing skeleton, bone plate, and navigation module were used for skeleton model and internal fixation. Screw and plate were placed by navigation. Navigation module card, nail and board position were observed. Postoperative appearance and CT scanning were utilized to assess outcomes. RESULTS AND CONCLUSION:After CT scanning and reconstructionin 20 skeleton models, in combination with appearance, the position of plate, screw insertion point, the direction, length and diameter of the screw were consistent with that in Mimics software. The navigation module and the corresponding proximal end of the tibia were closely bonded with good fitting degree. In the application, card slots and stability were good, and could perfectly guide plate and screw placement. These reuslts suggest that with the aid of navigation module, standard parts library plate internal fixation for proximal tibia fracture has high accuracy. On the basis of digital design and 3D printing, digital internal fixation technology of standard parts library plate is expected to achieve good implant navigation in the department of orthopedics.
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BACKGROUND:In three-dimensional CT reconstruction model, fracture virtual reduction and internal fixation cannot be achieved, and reasonable operation scheme cannot be formulated. It cannot fuly meet the needs of clinical orthopedics physicians. OBJECTIVE:To explore the methods to perform three-dimensional reconstruction, reduction on proximal tibial fracture and to design digital plate using software. METHODS:Nine specimens of knee joint were built to be A1-3, B1-3 and C1-3 types of proximal tibial fracture according to the AO standard. Al specimens were treated with CT scan. Three-dimensional reconstruction and reduction on nine types of bone fracture models were performed in Mimics. The digital plates and screws were designed in Solidworks. Virtual internal fixation on the reduced three-dimensional models was performed. RESULTS AND CONCLUSION:Al bone fracture models received three-dimensional reconstruction and reduction, and the design for internal fixational plates and screws as wel as virtual internal fixation were accomplished. A3, B3 and C3 types were presented. These results suggest that the digital plates for proximal tibial fracture could be designed in Mimics and Solidworks with a personal computer. Our experience could be used in the real operation.
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BACKGROUND:Odontoid fracture is very common in cervical spine injuries, the special position of odontoid process, which is adjacent to important anatomic structure, makes screw placement difficult, and a slight discrepancy in position and orientation of the inserted screw leads to a decrease in intensity of internal fixation, even invalid internal fixation. Therefore, it is very necessary to develop an individualized treatment protocol by which screws can be precisely and safely placed and which is worthy of clinical popularization. OBJECTIVE:To study the navigation of Mimics software and three dimensional (3D)-printed module in anterior odontoid cannulated screw fixation and to investigate its feasibility and accuracy. METHODS:Sixteen human cadaveric cervical spines were scanned by a continuous thin-slice CT scanner. Original DICOM CT images were three-dimensional y reconstructed using Mimics software. The screw channel and support column were designed for C2 vertebra odontoid cannulated screw fixation for odontoid fracture. Segmentation of bone surface was performed. Navigation modules with screw channel were built using 3D printing technique. Navigation modules were used to aid screw placement. Screw fitting and placement were evaluated using X-ray and CT scan. RESULTS AND CONCLUSION:Total y 16 navigation modules were built and 22 screws were implanted. During and after screw placement, the cortical bone along screw channel and surrounding the vertebral body was not cracked. Postoperative X-ray and CT scans showed that some factors regarding screw placement such as entry point, orientation and depth of placement were consistent with those ideal factors simulated by Mimics software. The navigation modules were closely attached to the corresponding bony structure in front of the vertebral body, with a satisfactory gomphosis. Screw fitting and stability were good during application. These results verify that with the aid of navigation module, anterior odontoid cannulated screw fixation is reliable for treatment of odontoid fracture, which provides insights into the popularization of 3D printing-based digital navigation technique in orthopedic implantation.
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10.3969/j.issn.2095-4344.2013.26.024
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OBJECTIVE: To establish HPLC method for the determination of the contents of atenolol, hydrochlorothiazide and nifedipine in xueyaan sustained release tablets. METHODS: The determination was performed on ZORBAX SB C18 column with column temperature at 35℃ . The mobile phase consisted of 0. 01mol? L- 1 sodium dihydrogen phosphate solution- methanol- acetonitrile ( 6∶ 3∶ 1) . The UV detection wavelength was set at 272nm and the sample size was 20? L. RESULTS: The liner ranges of atenolol, hydrochlorothiazide and nifedipine were 10～ 250? g? mL- 1 ( r=0. 999 4) , 6～ 150? g? mL- 1( r=0. 999 6) , and 5～ 125? g? mL- 1( r=0. 999 2) respectively. The average recovery rates of the three constituents were ( 98. 51? 0. 98) % ～ ( 99. 12? 0. 98) % , ( 98. 87? 1. 10) % ～ ( 99. 69? 1. 43) % , and( 98. 80? 1. 27) % ～ ( 99. 38? 1. 13) % , respectively, with RSD at 1. 00% , 1. 17% , and 1. 25% , respectively. CONCLUSION: The established method is simple, sensitive and reproducible, and suitable for the quality control of xueyaan sustained release tablets.