Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Hospital of Orthopaedics, Guangzhou General Hospital of Guangzhou Military Command (Liuhuaqiao Hospital), 111 Liuhua Road, Guangzhou, China.
Sci Rep. 2016 Aug 19;6:31648. doi: 10.1038/srep31648.
Clival screw and plate fixation technique is an alternative or supplement to the occipitocervical instrumentation. However, no report has clarified the applied anatomy of clivus in patients with atlas assimilation (C1A), especially for clival screw fixation. Therefore, we measured the parameters of clival lengths, widths, putative screw lengths, clival-cervical angel and foramen magnum diameters on CT images in a cohort of 81 C1A patients and patients without C1A. The clivus showed a rectangular shape in 96.3% (78/81) of C1A patients, and a normal-like triangle shape in 3.7% (3/81) of C1A patients. The intracranial clival length decreased 13% (37 mm) in C1A patients, the extracranial clival length 14.8% (24.1 mm), the clival-cervical angle 6.2% (122.3°) and the superior screw length 11.3% (14.1 mm), the sagittal diameter of foramen magnum 16% (28.0 mm), respectively. There was no significant difference in the widest or narrowest clival width, or the middle screw length, or the transverse diameter of foramen magnum between groups. The inferior clivus was feasible for an average 9.7-mm-length screw placement in C1A patients, while not in patients without C1A. The present study characterizes clivus of C1A patients with an unnormal-like rectangular shape, and confirmes a screw placement at the inferior clivus.
斜坡螺钉和钢板固定技术是枕颈器械的一种替代或补充方法。然而，目前尚无报道阐明寰椎融合（C1A）患者斜坡的应用解剖结构，特别是对于斜坡螺钉固定。因此，我们在 81 例 C1A 患者和无 C1A 患者的 CT 图像上测量了斜坡长度、宽度、潜在螺钉长度、斜坡-颈椎角度和枕骨大孔直径等参数。在 96.3%（78/81）的 C1A 患者中，斜坡呈矩形，在 3.7%（3/81）的 C1A 患者中呈正常三角形。C1A 患者颅内斜坡长度减少 13%（37mm），颅外斜坡长度减少 14.8%（24.1mm），斜坡-颈椎角度减少 6.2%（122.3°），上螺钉长度减少 11.3%（14.1mm），枕骨大孔矢状径减少 16%（28.0mm）。两组间斜坡最宽或最窄宽度、中间螺钉长度或枕骨大孔横径均无显著差异。C1A 患者的下斜坡平均可放置 9.7mm 长的螺钉，而无 C1A 患者则不可放置。本研究描述了 C1A 患者的斜坡呈非典型矩形，证实了在下斜坡进行螺钉固定的可行性。
