Wang Hongwei, Mo Zhongjun, Han Jianda, Liu Jun, Li Changqing, Zhou Yue, Xiang Liangbi, Yang Lei
Department of Orthopedics, General Hospital of Shenyang Military Area Command of Chinese PLA, Shenyang, Liaoning State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Science, Shenyang, Liaoning State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan, Hubei State Key Laboratory of Trauma, Burn and Combined Injury, Third Military Medical University, Chongqing National Research Center for Rehabilitation Aids, Beijing Department of Orthopedics, Xinqiao Hospital, The Third Military Medical University, Chongqing Department of Nutrition, General Hospital of Shenyang Military Area Command of Chinese PLA, Shenyang, Liaoning, China..
Medicine (Baltimore). 2018 Jun;97(26):e11244. doi: 10.1097/MD.0000000000011244.
Intermediate screw fixation at the fracture level has been widely accepted to treat thoracolumbar burst fractures, but no study has shown the effect of the extent and location of fixation. The effect of the extent and location of fixation on short- or long-segment pedicle screw fixation through intermediate screw fixation at the fracture level in the treatment of thoracolumbar burst fractures is discussed.Posterior intermediate screw fixation techniques in treating T12 vertebral fracture models were simulated and compared using finite element methods; the fixation techniques included M3-L1 (bilateral 3 monoaxial pedicle screw fixation from L1 to T11), M3-L2, M4-L1 (bilateral 4 monoaxial pedicle screw fixation from L1 to T10), M4-L2, M4-L3, and M5-L2 (bilateral 5 monoaxial pedicle screw fixation from L2 to T10). Range of motion (ROM) and largest von Mises stress (LVMS) of the instrumentations were recorded and analyzed.No significant differences were observed in the mean ROM of all states of motion between the M3-L1 model and the other fixation models except for M5-L2. The LVMS of the pedicle screws and rods all occurred during flexion. The LVMS values of the pedicle screws were larger in the M3-L2 fixation model and M4-L3 fixation model than in the other fixation models. The M3-L1 model presented a significantly smaller mean LVMS of the pedicle screws in all states of motion than the M3-L2 model (P = .026). The LVMS values of the rods were larger in the M3-L2 fixation model, M4-L3 fixation model, and M4-L2 fixation model than in the other fixation models. No significant differences were observed in the mean LVMS of the rods in all states of motion among all the fixation models.When choosing short-segment pedicle screw fixation with the screwing of fractured vertebrae to treat thoracolumbar fractures, we suggest M3-L1 over M3-L2. More severe injuries can be considered to identify an alternative treatment to long-segment monoaxial pedicle fixation constructs such as the M4-L1 and M5-L2 techniques.
在骨折节段进行中间螺钉固定已被广泛接受用于治疗胸腰椎爆裂骨折，但尚无研究表明固定范围和位置的效果。本文讨论了在骨折节段通过中间螺钉固定进行短节段或长节段椎弓根螺钉固定的范围和位置对胸腰椎爆裂骨折治疗的影响。使用有限元方法模拟并比较了治疗T12椎体骨折模型的后路中间螺钉固定技术；固定技术包括M3-L1（从L1到T11双侧3枚单轴椎弓根螺钉固定）、M3-L2、M4-L1（从L1到T10双侧4枚单轴椎弓根螺钉固定）、M4-L2、M4-L3和M5-L2（从L2到T10双侧5枚单轴椎弓根螺钉固定）。记录并分析了器械的活动范围（ROM）和最大冯·米塞斯应力（LVMS）。
除M5-L2外，M3-L1模型与其他固定模型在所有运动状态下的平均ROM均无显著差异。椎弓根螺钉和棒的LVMS均出现在屈曲过程中。M3-L2固定模型和M4-L3固定模型中椎弓根螺钉的LVMS值高于其他固定模型。在所有运动状态下，M3-L1模型椎弓根螺钉的平均LVMS显著小于M3-L2模型（P = 0.026）。M3-L2固定模型、M4-L3固定模型和M4-L2固定模型中棒的LVMS值高于其他固定模型。所有固定模型在所有运动状态下棒的平均LVMS均无显著差异。
在选择通过骨折椎体拧入螺钉进行短节段椎弓根螺钉固定治疗胸腰椎骨折时，我们建议选择M3-L1而非M3-L2。对于更严重的损伤，可考虑采用M4-L1和M5-L2技术等长节段单轴椎弓根固定结构的替代治疗方法。
