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Objective To investigate the primary application of 3D printing technique in vascularized fibula resection and grafting for mandible ameloblastoma. Methods The data of 3 cases of unilateral mandibular ameloblastoma were retrospectively collected.The thin slice CT scan of mandible was performed before operation.The scanned original data were imported into mimics 17.0 software for 3D reconstruction.Mirror image of the healthy side mandible was generated by the mirror image tool of the software.Preoperative planning,designing transplantation of vascularized fibula bone,pre-bending and pre-shaping titanium plate,surgical simulation were done by the mirror model.Results All operations were performed successfully,and were in agreement with the preoperative planning.The facial appearance and mandible function were both satisfactory.Conclusion 3D printing technology assisting mandibular ameloblastoma resection and bone graft reconstruction is able to optimize preoperative planning,provide individualized treatment and achieve postoperative satisfaction.
ABSTRACT
BACKGROUND: Posterior pedicle screw fixation of lower cervical spine has many advantages. However, because of the special anatomy of pedicle, the technical requirements of nailing placement are high and it is also a challenge to surgeons. The application of three-dimensional (3D) printing technology can help to complete screw placement, and has certain advantages. OBJECTIVE: To introduce the method of 3D printing personalized navigation template assisted posterior lower cervical pedicle screw fixation and evaluate its clinical application value. METHODS: Totally 20 patients with lower cervical spine pedicle screw internal fixation who were treated from June 2015 to December 2016 in Affiliated Hospital of Yan'an University were retrospectively analyzed. Before the surgery, the patient's lower cervical spine CT data was introduced into the relevant software and the 3D printing personalized navigation template assisted nailing pedicle screw was designed. The number of screws inserted was recorded. After the operation, CT scan was used to calculate the accuracy rate of screw placement. Preoperative and postoperative cervical spine Visual Analogue Scale score and spinal function score of Japanese Orthopedic Association were used to evaluate the clinical effect of cervical nerve. RESULTS AND CONCLUSION: (1) All patients were followed up for 3 months postoperatively. (2) 3D printing personalized navigation template assisted 132 pedicle screws. The precise insertion rate was 94.7%. Among them, 125 screws were at grade 0 (94.7%, 125/132), 3 screws grade 1 (2.3%, 3/132), 4 screws grade 2 (3.0%, 4/132), no screw grade 3. (3) At postoperative 1 and 3 months, the neck shoulder Visual Analogue Scale score and spinal function score of Japanese Orthopedic Association of the patients were significantly improved (P < 0.05), but there was no significant difference (P > 0.05), compared with those at preoperative. (4) In summary, 3D printing personalized navigation template assisted cervical pedicle screw placement had the high insertion rate and satisfactory clinical efficacy.
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BACKGROUND: Thoracolumbar fracture is commonly seen in spinal injuries, which causes loss of stability of the spine, as well as spinal cord and nerve compression, even deformity and paralysis. The diagnosis and treatment of thoracolumbar fracture remain controversial.OBJECTIVE: To summarize the mechanism of thoracolumbar fracture based on finite element method, its classification and transpedicular screw fixation.METHODS: The first author retrieved CNKI and PubMed databases for the relevant literature published between January 2000 and December 2016. The keywords were "finite element method, thoracolumbar spine fracture,transpedicular screw fixation" in Chinese and English, respectively.RESULTS AND CONCLUSION: (1) The finite element analysis method can simulate the mechanism of thoracolumbar fracture and provides a reference for the studies on the occurrence, development and treatment of thoracolumbar fracture. (2) The classification of thoracolumbar fracture is beneficial for planning a rational treatment strategy and evaluating prognosis. (3) Compared with the traditional screw fixation, the transpedicular screw fixation holds advantages in biomechanical stability and postoperative correction effect. (4) There are various classifications for thoracolumbar fracture; differences in severity and cartilage injury are difficult to simulate completely. (5) The finite element analysis method shows certain application limitations due to long learning curve and modeling time as well as complicated calculations.
ABSTRACT
BACKGROUND: The lower cervical pedicle screw fixation is the most stable internal fixation of the cervical spine in biomechanics, which can penetrate the anterior, middle and posterior columns of the spine, effectively restore the sagittal sequence of the cervical spine, provide strong internal fixation and high fusion rate. OBJECTIVE: To review the relevant information of the anatomical structure of lower cervical pedicle, the biomechanical property of screw fixation, and three-dimensional printing technology-assisted screw placement at home and abroad. METHODS: PubMed and CNKI databases were searched for the articles concerning lower cervical pedicle screw fixation from January 1990 to January 2017. The key words were "lower cervical, pedicle screw, 3D printing technology" in Chinese and English, respectively. Totally 193 articles were researched, and the repetitive research, case report and meta-analysis were excluded. RESULTS AND CONCLUSION: (1) Finally 52 eligible articles were enrolled for result analysis. (2) Although it has a very high risk to fix lower cervical pedicle screw, the risk could be minimized or avoided through fully individualized evaluation preoperatively and precise fixation intraoperatively. So the lower cervical pedicle screw fixation has high clinical value.