BACKGROUND:The limitation of the traditional intramedulary nailing relies on the personal experience of the doctor. Moreover, the enlargement of the bone marrow causes the destruction of the biological environment of the marrow cavity and affects the healing of bone. OBJECTIVE:To observe therapeutic effect of digital technology assisted intramedulary nail fixation for femoral shaft fracture. METHODS:A total of 80 patients with femoral shaft fracture, who were treated in the Department of Orthopedics, Affiliated Hospital of Putian University from January 2010 to January 2014, were enroled. Digital technology was used to assist treatment. Three-dimensional digital model of femoral shaft fracture was established before treatment. Virtual reduction was conducted in the three-dimensional digital fractures. The diameter of medulary cavity was measured. Appropriate specification of intramedulary nailing was selected according to the measurement data. Closed reduction and intramedulary nailing were performed according to operation scheme of digital technology. RESULTS AND CONCLUSION:The 80 patients were folowed up for 12 to 24 months. Fractures were completely healed. At 12 months after treatment, they were evaluated by clinical curative effect standard in department of orthopedics. There were excelent in 62 cases, good in 15 cases, and good in 3 cases, with the excelent and good rate of 96%. No complications occurred such as infection, fixator breakage or loosening. These results verify that digital technology assisted intramedulary nail fixation for femoral shaft fracture obtained positive therapeutic effects, could obviously shorten operation time, reduce surgical trauma, and diminish intraoperative X-ray emission to patients and health care workers.

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.

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.

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.

Objective    To evaluate the prognosis of interventional treatment with covered stent graft for retrograde Stanford type A aortic dissection and intramural hematoma by single-arm meta-analysis. Methods    Related studies on treating retrograde Stanford type A aortic dissection and intramural hematoma with covered stent graft were retrieved from the databases by computer, including PubMed, EMbase, The Cochrane Library, Wanfang Data, VIP, CNKI and CBM, from inception to January 2020. Literatures were screened by researchers step by step according to the predefined inclusion and exclusion criteria. Quality of the enrolled literatures was evaluated, and data were extracted from the included studies. Afterwards, single-arm meta-analysis was carried out by the R3.6.3 software. Results    A total of 12 English and 5 Chinese studies were included, which were all case series, and the quality of all literatures was moderate evaluated by Newcastle-Ottawa Scale (NOS). After analyzing the clinical prognosis of 260 patients, the 30-day mortality was 6% (95%CI 0.04 to 0.11, P=0.97), the late mortality was 8% (95%CI 0.05 to 0.14, P=0.78), the incidence of endoleak was 21% (95%CI 0.16 to 0.29, P=0.06), the incidence of stroke was 5% (95%CI 0.03 to 0.09, P=0.99), the incidence of new aortic dissection was 7% (95%CI 0.04 to 0.11, P=0.96), the incidence of dissection progression was 10% (95%CI 0.07 to 0.16, P=0.24), and the absorption rate of intramural hematoma was 84% (95%CI 0.37 to 1.00, P<0.01). Conclusion    Interventional treatment with covered stent graft for retrograde Stanford type A aortic dissection and intramural hematoma can obtain good early treatment results for some patients, and can be used as a safe and effective treatment for aged patient with high risk who cannot tolerate surgery. Endoleak, stroke and new aortic dissection are the early serious complications of this method.