Wang Long, Zhao Yong-Hui, Cai Xing-Bo, Liang Jin-Long, Luo Hao-Tian, Ma Yu-Long, Xu Yong-Qing, Lu Sheng
Postgraduate College of Kunming Medical University, No. 1168 Chunrong Xi Road, Kunming, China.
Department of Orthopedics, 920th Hospital of Joint Logistics Support Force, 212 Daguan Road, Kunming, China.
Medicine (Baltimore). 2021 Jul 16;100(28):e26666. doi: 10.1097/MD.0000000000026666.
To investigate the feasibility of using cortical bone trajectory (CBT) screws for bridging fixation in revision surgery for lumbar adjacent segment degeneration and to provide a reference for clinical practice.
Computed tomography scans of the lumbar spines of 36 patients in our hospital were used. Sixteen males and 20 females with an average age of 65.5 ± 10.5 years (range: 46 to 83 years) were included. Three-dimensional reconstruction was performed using computer software. Screws with appropriate sizes were selected for the L1 to L5 vertebral segments, and traditional pedicle screws were placed using the standard method. After completing screw placement, simulated placement of CBT screws was performed separately. No overlap occurred between the two screws in the process of CBT screw placement, and the placement point and direction were adjusted until screw placement completion. After all screw placement simulations were complete, according to the contact area of the cortical bone of the screw trajectory and the screw puncture position and distance through the trajectory, the screw placement results were categorized as excellent, good, general, and failure. Excellent and good ratings were considered successful, while a general rating was regarded as acceptable. Then, the success rate and acceptable rate of each segment of the lumbar spine were calculated.
Three hundred and sixty screw placement simulations were performed in lumbar pedicles, and 72 CBT screws were implanted in each vertebral body of the lumbar spine. The success rates in the L1 to L5 segments were 73.6%, 80.6%, 83.3%, 88.9%, and 77.8%, respectively, and the acceptable rates were 91.7%, 97.2%, 97.2%, 100%, and 91.7%, respectively. The overall success rate and acceptable rate of CBT screw placement in the lumbar spine were 80.8% and 95.6%, respectively.
CBT screws are feasible for bridging fixation in lumbar adjacent segment degeneration revision surgery, and the accuracy of screw placement in different lumbar vertebrae varies.
探讨皮质骨轨迹（CBT）螺钉在腰椎相邻节段退变翻修手术中进行桥接固定的可行性，为临床实践提供参考。
采用我院36例患者的腰椎计算机断层扫描。纳入16例男性和20例女性，平均年龄65.5±10.5岁（范围：46至83岁）。使用计算机软件进行三维重建。为L1至L5椎体节段选择合适尺寸的螺钉，并采用标准方法置入传统椎弓根螺钉。完成螺钉置入后，分别进行CBT螺钉的模拟置入。在CBT螺钉置入过程中，两枚螺钉之间不发生重叠，并调整置入点和方向直至螺钉置入完成。所有螺钉置入模拟完成后，根据螺钉轨迹皮质骨的接触面积以及螺钉穿刺轨迹的位置和距离，将螺钉置入结果分为优、良、一般和失败。优和良等级视为成功，一般等级视为可接受。然后计算腰椎各节段的成功率和可接受率。
在腰椎椎弓根进行了360次螺钉置入模拟，腰椎每个椎体植入72枚CBT螺钉。L1至L5节段的成功率分别为73.6%、80.6%、83.3%、88.9%和77.8%，可接受率分别为91.7%、97.2%、97.2%、100%和91.7%。腰椎CBT螺钉置入的总体成功率和可接受率分别为80.8%和95.6%。
CBT螺钉在腰椎相邻节段退变翻修手术中进行桥接固定是可行的，不同腰椎节段螺钉置入的准确性有所差异。
