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.
ABSTRACT
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.