Department of Spinal Surgery, First Faculty of Medicine, Teaching Hospital Motol, Charles University, V Úvalu 84, 150 06, Prague 5, Czech Republic.
Department of Imaging Methods, Second Faculty of Medicine, Teaching Hospital Motol, Charles University, V Úvalu 84, 150 06, Prague 5, Czech Republic.
Eur Spine J. 2019 Feb;28(2):317-323. doi: 10.1007/s00586-018-5793-8. Epub 2018 Oct 22.
The most common injuries to the upper cervical spine are fractures of the dens axis. Therefore, the purpose of our study was to answer three questions, namely (1) whether the size of the dens is adequate at all levels to accommodate two screws, (2) what the angle of the posterior tilt of the dens is in a healthy individual and (3) compare the measured variables between the sexes.
The cohort comprised 50 males and 50 females CT examination of the craniocervical junction. We measured the five diameters of the dens and posterior dens angulation angle (PDAA) and screw insertion angle (SIA). The same dimensions were measured in a control group, consisting of 40 non-pathological second cervical vertebrae specimens.
On CT scans, the mean PDAA was 162.7 degrees in males and 160.26 degrees in females; the mean SIA was 62.0 degrees in males and 60.2 degrees in females. On specimens, the mean PDAA was 169.47 degrees in males and 166.95 degrees in females; the mean SIA was 65.42 degrees in males and 64.47 degrees in females. All obtained values were higher in males; regardless of their measuring on either CT scans or specimens, differences between males and females were statistically significant (p < 0.05) in a, c, d and e values.
The values of our measurements correlate with the dimensions identified previously in other studies. Based on our clinical experience and measurements, we presume that two 3.5-mm screws can be inserted into the dens of all adult patients, except for those with pronounced anatomical anomalies. Posterior dens angulation angle is slightly larger than we expected. The dens is significantly larger in males almost in all measurement. These slides can be retrieved under Electronic Supplementary Material.
上颈椎最常见的损伤是枢椎齿状突骨折。因此，我们的研究目的是回答三个问题，即（1）所有水平的齿状突大小是否足以容纳两颗螺钉，（2）健康个体的齿状突后倾角度是多少，（3）比较男女之间的测量变量。
该队列包括 50 名男性和 50 名女性的颅颈交界区 CT 检查。我们测量了齿状突的五个直径和齿状突后倾角（PDAA）和螺钉插入角（SIA）。在一个由 40 个非病理性第二颈椎标本组成的对照组中测量了相同的尺寸。
在 CT 扫描中，男性的平均 PDAA 为 162.7 度，女性为 160.26 度；男性的平均 SIA 为 62.0 度，女性为 60.2 度。在标本中，男性的平均 PDAA 为 169.47 度，女性为 166.95 度；男性的平均 SIA 为 65.42 度，女性为 64.47 度。所有获得的值在男性中都较高；无论在 CT 扫描还是标本上进行测量，男性和女性之间的差异在 a、c、d 和 e 值方面均具有统计学意义（p<0.05）。
我们的测量值与先前在其他研究中确定的尺寸相关。根据我们的临床经验和测量，我们推测除了具有明显解剖异常的患者外，所有成年患者的齿状突都可以插入两颗 3.5 毫米的螺钉。齿状突后倾角略大于我们的预期。男性的齿状突几乎在所有测量中都明显更大。这些幻灯片可以在电子补充材料中检索。
