Department of Spine Surgery, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.
Department of Spine Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China.
World Neurosurg. 2020 Jul;139:e691-e699. doi: 10.1016/j.wneu.2020.04.108. Epub 2020 Apr 24.
The pedicle-rib unit is regarded as an expanded pedicle and is a new approach to thoracic pedicle fixation. Previous studies were mostly focused on anatomic, radiographic, and biomechanical assessment. However, there is no study on anatomic relationship of bony structures in the pedicle-rib unit. This article investigates the anatomic relationships between transverse process, pedicle, rib, and corresponding vertebrae body in the pedicle-rib unit, so as to improve the clinical safety of pedicle-rib unit screw placement.
Forty-five normal dry adult cadaver specimens were included. Anatomic parameters were measured. Anatomic parameters were 1) the anatomic relationship between the transverse process and the pedicle (the distance from the horizontal center line of the transverse process to the center and the superior and inferior border of the pedicle); 2) the anatomic relationship between the transverse process and the rib (the overlap portion between the costal neck and the transverse process); 3) the anatomic relationship between the transverse process and the vertebral body (the relative position of the horizontal midline of the transverse process and the vertebral body); and 4) the anatomic relationship between the pedicle and the rib (the overlap portion between the costal neck and the pedicle).
The midline of the transverse process was located within the range of the superior and inferior borders of the pedicle in the thoracic spine. The distance between the midline of the transverse process and the center of the pedicle was the closest at T6 and T7, but the farthest at T11 and T12. The anterolateral part of the transverse process was mostly covered by rib from T1 to T8, but it was less covered from T9 to T12. The midline of the transverse process corresponded to the upper third or middle third of the vertebral body. The pedicle is completely or mostly overlapped by the rib from T1 to T9 on the anterolateral side, but from T10 to T12, the rib overlapped the pedicle partially.
The pedicle-rib unit is a three-dimensional anatomic structure. The pedicle, transverse process, and rib are not completely in the same plane, and their positions vary in different segments. Pedicle-rib unit screw fixation is anatomically feasible. Setting the screw in the upper-middle thoracic spine is safer than setting it in the lower thoracic spine.
肋-椎骨单元被视为扩展的椎弓根，是一种新的胸椎椎弓根固定方法。以前的研究主要集中在解剖学、影像学和生物力学评估上。然而，目前还没有关于肋-椎骨单元中骨结构解剖关系的研究。本文旨在研究肋-椎骨单元中横突、椎弓根、肋骨和相应椎体之间的解剖关系，以提高肋-椎骨单元螺钉置入的临床安全性。
纳入 45 具正常成人干尸标本。测量解剖学参数。测量的解剖学参数包括：1）横突与椎弓根的解剖关系（横突的水平中心线距椎弓根中心、上缘和下缘的距离）；2）横突与肋骨的解剖关系（肋颈与横突重叠部分）；3）横突与椎体的解剖关系（横突的水平中线与椎体的相对位置）；4）椎弓根与肋骨的解剖关系（肋颈与椎弓根重叠部分）。
胸椎的横突中线位于椎弓根上下缘范围内。横突中线与椎弓根中心的距离在 T6 和 T7 处最近，但在 T11 和 T12 处最远。T1 至 T8 的横突前外侧大部分被肋骨覆盖，而 T9 至 T12 则较少被覆盖。横突中线与椎体的上三分之一或中三分之一相对应。T1 至 T9 的横突前外侧部，椎弓根完全或大部分被肋骨覆盖，但 T10 至 T12 时，肋骨部分覆盖椎弓根。
肋-椎骨单元是一个三维解剖结构。椎弓根、横突和肋骨不完全在同一平面上，它们在不同节段的位置不同。肋-椎骨单元螺钉固定在解剖学上是可行的。在上中胸椎设置螺钉比在下胸椎设置螺钉更安全。
