Biomechanical evaluation of internal fixation combined with injured vertebrae cement reinforcement in the treatment of osteoporotic thoracolumbar burst fractures#br#
ZHAI Weifeng1 JIA Yongwei1 YAN Hao1 NI Ming2 ZHANG Jianpo1 WEI Licheng1 HUANG Zheng1 JIN Lang1
1.Department of Spine Surgery, Guanghua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200052, China;
2.Department of Orthopaedics, Pudong New Area People’s Hospital, Shanghai University of Medicine and Health Sciences, Shanghai 201299, China
Abstract Objective To evaluate the stability of internal fixation combined with injured vertebrae cement reinforcement in the treatment of osteoporotic thoracolumbar burst fracture, and to provide reference for clinical application. Methods Six elderly thoracolumbral (T11-L3) spinal specimens were collected by Shanghai University of Traditional Chinese Medicine from January 2018 to June 2019 to prepare L1 vertebral body burst fracture model. Then biomechanical tests were performed in the order of complete state (blank group), fracture state (fracture group), 6-screw internal fixation state (6-screw group), 6-screw internal fixation combined with injured vertebrae cement reinforcement state (6-screw + cement group), and 4-screw internal fixation combined with injured vertebrae cement reinforcement state (4-screw + cement group). The specimens in each group were tested in different stages of flexion, extension, left and right bending and axial compression respectively. The deformation images of the specimens were collected by CCD camera. Based on Image J software, digital marker point centroid tracking method was used to measure the vertical displacement of T12 on the coronal plane to reflect the stiffness of the fixed segment, and the comparison was made. Results Under axial compression, flexion, extension, and left and right bending loading modes, the specimen stiffness of fracture group was significantly lower than that of blank group, 6-screw group, 4-screw + cement group, and 6-screw + cement group, with statistically significant differences (P < 0.05). The stiffness of specimens in the 6-screw group was higher than that in the blank group under extension and left and right bending loading modes, and the stiffness of specimens in the 6-screw group was lower than that in the blank group under axial compression and forward bending loading modes, with statistical significance (P < 0.05). Under axial compression, extension, and left and right bending loading modes, the stiffness of specimens in the 4 screw + cement group and 6 screw + cement group were higher than those in the blank group and 6 screw group, and the 6 screw + cement group was higher than the 4 screw + cement group, the differences were statistically significant (P < 0.05). In flexion loading mode, the stiffness of specimens in the 4 screws + cement group was lower than that of the blank group but higher than that of the 6 screws group, and the 6 screws + cement group was higher than those of the blank group and the 6 screws group, with statistical significance (P < 0.05). Conclusion The three fixation methods can achieve the stability of the fixed segment, but the 6-screw internal fixation combined with injured vertebrae cement reinforcement has the strongest stability and the best biomechanical performance.
ZHAI Weifeng1 JIA Yongwei1 YAN Hao1 NI Ming2 ZHANG Jianpo1 WEI Licheng1 HUANG Zheng1 JIN Lang1. Biomechanical evaluation of internal fixation combined with injured vertebrae cement reinforcement in the treatment of osteoporotic thoracolumbar burst fractures#br#[J]. 中国医药导报, 2021, 18(30): 96-100.
