Ugur H C, Attar A, Uz A, Tekdemir I, Egemen N, Genç Y
Department of Neurosurgery, The University of Ankara, Faculty of Medicine, Turkey.
J Spinal Disord. 2001 Feb;14(1):39-45. doi: 10.1097/00002517-200102000-00007.
This anatomic study investigated the thoracic pedicle and its relations. The objective was to emphasize the importance of the thoracic pedicle for transpedicular screw fixation to avoid complications during surgery. Twenty cadavers were used to observe the cervical pedicle and its relations. The isthmus of the pedicle was exposed after removal of whole-posterior bony elements, including spinous processes, laminas, lateral masses, and the inferior and superior facets. The pedicle width and height, interpedicular distance, pedicle-inferior nerve root distance, pedicle-superior nerve root distance, pedicle-dural sac distance, root exit angle, and nerve root diameter were measured. There was no distance between the pedicle and dural sac in eight specimens. There was, however, a short distance in 12 remaining specimens in the upper and lower thoracic regions. The distances between the thoracic pedicle and the adjacent nerve roots ranged from 1.5 to 6.7 mm and 0.8 to 6.0 mm superiorly and inferiorly at all levels. The mean pedicle height and width at T1-T12 ranged from 2.9 to 11.4 mm and 6.2 to 21.3 mm, respectively. The interpedicular distance decreased gradually from T1 to T5 and then increased gradually to T12. The mean root exit angle decreased consistently from 104 degrees to 60 degrees. The nerve root diameter was between 2.3 and 2.5 mm at the T1-T5 level and then increased consistently from 2.5 to 3.7 mm. All significant differences were noted at p < 0.05 and p < 0.01. The following suggestions are made based on these results. 1) More care should be taken when a transpedicular screw is placed in the horizontal plane. 2) Improper medial placement of the pedicle screw, especially in the middle thoracic spine, should be avoided, and the anatomic variations between individuals should be considered. 3) Because of substantial variations in the size of thoracic pedicles, utmost attention should be given to the findings of a computed tomographic evaluation before thoracic transpedicular fixation is begun.
本解剖学研究对胸椎椎弓根及其关系进行了调查。目的是强调胸椎椎弓根在经椎弓根螺钉固定中的重要性，以避免手术过程中出现并发症。使用20具尸体观察颈椎椎弓根及其关系。在去除包括棘突、椎板、侧块以及上下关节突在内的整个后部骨质结构后，暴露椎弓根峡部。测量椎弓根的宽度和高度、椎弓根间距、椎弓根与下位神经根的距离、椎弓根与上位神经根的距离、椎弓根与硬脊膜囊的距离、神经根出口角度以及神经根直径。8个标本中椎弓根与硬脊膜囊之间没有距离。然而，在其余12个标本的上胸椎和下胸椎区域存在较短距离。在所有节段，胸椎椎弓根与相邻神经根之间的距离在上位和下位分别为1.5至6.7毫米和0.8至6.0毫米。T1 - T12的椎弓根平均高度和宽度分别为2.9至11.4毫米和6.2至21.3毫米。椎弓根间距从T1到T5逐渐减小，然后从T5到T12逐渐增加。平均神经根出口角度从104度持续减小到60度。在T1 - T5水平神经根直径在2.3至2.5毫米之间，然后从2.5至3.7毫米持续增加。所有显著差异均在p < 0.05和p < 0.01时被发现。基于这些结果提出以下建议。1）在水平面置入经椎弓根螺钉时应更加小心。2）应避免椎弓根螺钉向内侧放置不当，尤其是在胸椎中段，并且应考虑个体之间的解剖变异。3）由于胸椎椎弓根大小存在显著差异，在开始胸椎经椎弓根固定之前，应极其重视计算机断层扫描评估的结果。
