Department of Anatomy and Human Embryology, Faculty of Medicine, University of Valencia, Avda Blasco Ibanez 15, E46010 Valencia, Spain.
Department of Anatomy and Human Embryology, Faculty of Medicine, University of Valencia, Avda Blasco Ibanez 15, E46010 Valencia, Spain.
Spine J. 2018 Nov;18(11):2102-2111. doi: 10.1016/j.spinee.2018.06.352. Epub 2018 Jun 28.
The retrotransverse foramen (RTF), arcuate foramen (AF), unclosed transverse foramen (UTF) and posterior atlas arch defects (PAAD) are anatomic variations of the atlas vertebra that surgeons must be aware of before spine surgery is performed.
To analyze the prevalence of the AF, RTF, UTF, and PAAD.
Ex-vivo anatomical study.
Two hundred eighteen atlas vertebrae obtained from 100 Caucasian subjects and 118 sub-Saharan African subjects (48 Sotho subjects, 35 Xhosa subjects and 35 Zulu subjects).
We studied 218 atlas vertebrae from skeletons of the Raymond A. Dart Collection in order to analyze the prevalence of AF, RTF, UTF, and PAAD in both Caucasian and sub-Saharan African subjects.
Not applicable.
Sixty-nine (31.2%) atlases presented anatomical variants: 64 (29.3%) presented one anatomical variant, 4 (1.8%) presented two, and 1 (0.5%) presented three. AF, RTF, UTF, Type A and Type E defects were present in 35 (16.1%), 17 (7.8%), 17 (7.8%), 5 (2.3%), and 1 (0.5%) vertebrae, respectively. The vertebrae with two anatomical variants presented a bilateral UTF and a Type A defect, a bilateral AF and a Type A defect, a right UTF and a left AF, and a right UTF and a Type E defect. The vertebra with three anatomical variants presented a bilateral RTF, a left UTF, and a left AF. No sex differences in prevalence of the RTF (p=.775), AF (p=.605), UTF (p=.408) and Type A defects (p=1.000) were found in the sub-Saharan African and Caucasian groups (RTF, p=.306; AF, p=.346; UTF, p=.121; Type A defects, p=.561). Comparison between the sub-Saharan African (all subjects) and the Caucasian group revealed no differences in the UTF (p=.105), AF (p=.144), RTF (p=.542) and Type A defects (p=.521) prevalence. Also, no differences in the prevalence of the UTF (p=.515), AF (p=.278), and RTF (p=.857) between Zulu, Xhosa and Sotho subjects were found. Neither were found sex differences in the prevalence of UTF, RTF and AF in Zulu (p=.805, p=.234, p=.129), Xhosa (p=.269, p=.181, p=.309), and Sotho subjects (p=.062, p=.590, p=.106).
The present study has revealed no sex differences in the prevalence of AF, UTF, RTF or PAAD in both Caucasian and sub-Saharan African subjects. This research has also indicated no differences in the prevalence of the UTF, AF and RTF between Zulu, Xhosa and Sotho subjects. In addition, this study has revealed no differences in the Type A, UTF, AF, and RTF prevalence between the sub-Saharan African (all subjects) and the Caucasian subjects. These variations may be known by surgeons before spine surgery for better planning.
后路横突孔（RTF）、弓状孔（AF）、未闭合的横突孔（UTF）和后寰椎弓缺陷（PAAD）是寰椎的解剖变异，脊柱外科医生在进行脊柱手术前必须了解这些变异。
分析 AF、RTF、UTF 和 PAAD 的发生率。
尸体解剖研究。
来自 100 名白种人和 118 名撒哈拉以南非洲人的 218 个寰椎，其中包括 48 名索托人、35 名科萨人和 35 名祖鲁人。
我们研究了雷蒙德·A·达特收藏的 218 个寰椎，以分析白种人和撒哈拉以南非洲人群中 AF、RTF、UTF 和 PAAD 的发生率。
69 个（31.2%）寰椎存在解剖变异：64 个（29.3%）存在一个解剖变异，4 个（1.8%）存在两个，1 个（0.5%）存在三个。AF、RTF、UTF、A型和 E 型缺陷分别出现在 35 个（16.1%）、17 个（7.8%）、17 个（7.8%）、5 个（2.3%）和 1 个（0.5%）的寰椎中。存在两个解剖变异的寰椎表现为双侧 UTF 和 A 型缺陷、双侧 AF 和 A 型缺陷、右侧 UTF 和左侧 AF、右侧 UTF 和 E 型缺陷。存在三个解剖变异的寰椎表现为双侧 RTF、左侧 UTF 和左侧 AF。在撒哈拉以南非洲和白种人组中，RTF（p=.775）、AF（p=.605）、UTF（p=.408）和 A 型缺陷（p=1.000）的发生率均无性别差异（RTF，p=.306；AF，p=.346；UTF，p=.121；A 型缺陷，p=.561）。比较撒哈拉以南非洲（所有受试者）和白种人组，UTF（p=.105）、AF（p=.144）、RTF（p=.542）和 A 型缺陷（p=.521）的发生率均无差异。此外，祖鲁人、科萨人和索托人之间的 UTF（p=.515）、AF（p=.278）和 RTF（p=.857）的发生率也无差异。祖鲁人（p=.805，p=.234，p=.129）、科萨人（p=.269，p=.181，p=.309）和索托人（p=.062，p=.590，p=.106）的 UTF、RTF 和 AF 发生率也无性别差异。
本研究未发现白种人和撒哈拉以南非洲人群中 AF、UTF、RTF 或 PAAD 的发生率存在性别差异。本研究还表明，祖鲁人、科萨人和索托人之间 UTF、AF 和 RTF 的发生率无差异。此外，本研究还表明，撒哈拉以南非洲（所有受试者）和白种人之间的 UTF、AF 和 RTF 发生率无差异。这些变异可能在脊柱外科手术前为外科医生所了解，以便更好地进行规划。
