Watanabe Noriyuki, Takigawa Tomoyuki, Uotani Koji, Oda Yoshiaki, Misawa Haruo, Tanaka Masato, Ozaki Toshifumi
Department of Orthopaedic Surgery, Okayama University Hospital, Okayama, Japan.
Department of Orthopaedic Surgery, National Hospital Organization Iwakuni Clinical Center, Yamaguchi, Japan.
Asian Spine J. 2022 Dec;16(6):874-881. doi: 10.31616/asj.2021.0268. Epub 2022 Feb 22.
This is a virtual three-dimensional (3D) imaging study examining computed tomography (CT) data to investigate instrumentation placement.
In this study, we aim to clarify the ideal entry point and trajectory of the sacral alar iliac (SAI) screw in relationship to the dorsal foramen at S1 and the respective nerve root.
To the best of our knowledge, there is yet no detailed 3D imaging study on the ideal entry point of the SAI screw. Despite the evidence suggesting that the dorsal foramen at S1 is a landmark on the sacrum, the S1 nerve root disruption is a general concern during the insertion of SAI screws. No other study has been published examining the nerve root location at the S1and SAI screw insertions.
Preoperative CT data from 26 patients pertaining to adult spinal deformities were investigated in this study. We applied a 3D image processing method for a detailed investigation. Virtual cylinders were used to mimic SAI screws. These were placed to penetrate the sacral iliac joint without violating the other cortex. We then assessed the trajectory of the longest SAI screw and the ideal entry point of SAI using a color mapping method on the surface of the sacrum. We measured the location of the nerve root at S1 in relation to the foramen at S1 and the sacral surface.
As per the results of our color mapping, it was determined that areas that received high scores are located medially and caudally to the dorsal foramen of S1. The mean angle between a horizontal line and a line connecting the medial edge of the foramen and nerve root at S1 was 93.5°. The mean distances from the dorsal medial edge of the foramen and sacral surface to S1 nerve root were 21.8 mm and 13.9 mm, respectively.
The ideal entry point of the SAI screw is located medially and caudally to the S1 dorsal foramen based on 3D digital mapping. It is also shown that this entry point spares the S1 nerve root from possible iatrogenic injuries.
这是一项虚拟三维（3D）成像研究，通过检查计算机断层扫描（CT）数据来研究器械置入情况。
在本研究中，我们旨在明确骶骨翼髂骨（SAI）螺钉相对于S1背侧孔及相应神经根的理想进针点和轨迹。
据我们所知，尚未有关于SAI螺钉理想进针点的详细3D成像研究。尽管有证据表明S1背侧孔是骶骨上的一个标志，但在插入SAI螺钉过程中，S1神经根损伤仍是一个普遍关注的问题。尚未有其他研究发表关于S1和SAI螺钉置入时神经根位置的情况。
本研究调查了26例成人脊柱畸形患者的术前CT数据。我们应用一种3D图像处理方法进行详细研究。使用虚拟圆柱体模拟SAI螺钉。将其放置在穿透骶髂关节且不侵犯其他皮质的位置。然后，我们使用一种颜色映射方法在骶骨表面评估最长SAI螺钉的轨迹和SAI的理想进针点。我们测量了S1神经根相对于S1孔和骶骨表面的位置。
根据我们的颜色映射结果，确定得分较高的区域位于S1背侧孔的内侧和尾侧。S1水平直线与连接孔内侧边缘和神经根的直线之间的平均角度为93.5°。从孔的背内侧边缘和骶骨表面到S1神经根的平均距离分别为21.8毫米和13.9毫米。
基于3D数字映射，SAI螺钉的理想进针点位于S1背侧孔的内侧和尾侧。还表明该进针点可使S1神经根免受可能的医源性损伤。
Zotero 插件
