Multidirectional instability of the thoracic spine due to iatrogenic pedicle injuries during transpedicular fixation. A biomechanical investigation.
Multidirectional instability of the thoracic spine due to iatrogenic pedicle injuries during transpedicular fixation. A biomechanical investigation.
复制标题
经椎弓根固定期间由于医源性椎弓根损伤导致胸椎多向不稳定。
DOI：
10.1097/00007632-199708150-00008
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发表时间：
1997
期刊：
影响因子：
3
通讯作者：
Liu,W
中科院分区：
文献类型：
--
作者：
Kothe,R;Panjabi,MM;Liu,W
研究设计：在体外模型中模拟椎弓根骨折，并量化其对椎弓根器械提供的多向稳定性的影响。目的：量化不同医源性椎弓根损伤导致的椎弓根器械多向灵活性。背景资料总结：螺钉错位和医源性椎弓根骨折是椎弓根器械的主要并发症。尽管越来越多的临床研究涉及这个问题，但关于术中椎弓根内固定的生物力学影响的可靠信息很少。方法：在10具人体尸体的5个椎体脊柱标本中，从中、下胸椎区域，建立爆裂性骨折。用半刚性椎弓根螺钉固定器械稳定骨折。为了模拟术中椎弓根骨折，分四步切除内固定节段的椎弓根。每个椎弓根损伤后，三维灵活性的活动范围和中立区的结构的形式进行了测定，并与完整的values.Results. Detection椎弓根的影响不大的多方向屈曲-伸展的稳定性所提供的仪器。当切除外侧壁时，中胸椎的轴向旋转显著增加（活动范围，8.2 vs. 3.6;中性区，4.2 vs. 1.7），而在下胸椎，仅当切除所有椎弓根时才显著增加（活动范围，3.8 vs. 1.4;中性区，1.1 vs. 0.4）。侧切椎弓根导致两侧中胸椎侧弯的活动范围和中立区显著增加（活动度，19.0 vs. 10.0;中性区，2.4 vs. 1.1）和下胸椎结论：椎弓根切除导致器械提供的轴向旋转和侧弯稳定性显著降低。这种影响在中胸椎高于下胸椎，可能与这些区域使用椎弓根螺钉产生的椎弓根骨折有关。
Study Design.Pedicle fracture was simulated in an in vitro model, and its effect on multidirectional stability provided by pedicle instrumentation was quantified.Objectives.To quantify the multidirectional flexibility of pedicle instrumentation due to different iatrogenic pedicle injuries.Summary of Background Data.Misplacement of the screw and iatrogenic pedicle fracture are the main complications of pedicle instrumentation. Despite the increasing number of clinical studies dealing with this issue, there is little reliable information concerning the biomechanical effects of an intraoperative pedicle fracture.Methods.A burst fracture was created in 10 human cadaveric five-vertebrae spine specimens, from the middle and lower thoracic spine regions. The fracture was stabilized with a semirigid pedicle screw fixation device. To simulate an intraoperative pedicle fracture, the pedicles of the instrumented segments were resected in four steps. After each pedicle injury, three-dimensional flexibility in the form of range of motion and neutral zone of the construct was determined and compared with the intact values.Results.Resection of the pedicles had little effect on the multidirectional flexion-extension stability provided by the instrumentation. There were significant increases of axial rotation in the middle thoracic spine when the lateral wall was resected (range of motion, 8.2 vs. 3.6; neutral zone, 4.2 vs. 1.7), whereas in the lower thoracic spine, significant increases occurred only when all the pedicles were resected (range of motion, 3.8 vs. 1.4; neutral zone, 1.1 vs. 0.4). Lateral resection of the pedicle resulted in significant increases of range of motion and neutral zone for lateral bending in both the middle thoracic spine (range of motion, 19.0 vs. 10.0; neutral zone, 2.4 vs. 1.1) and the lower thoracic spine (range of motion, 4.3 vs. 2.5; neutral zone, 0.9 vs. 0.3).Conclusions.Resection of the pedicles results in a significant decrease in axial rotation and lateral bending stability provided by the instrumentation. This effect was higher in the middle than in the lower thoracic spine and may be relevant to pedicle fractures produced by pedicle screws used in these regions.