DeRouen Anthony, Spriet Mathieu, Aleman Monica
William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA, 95616.
the Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, 95616.
Vet Radiol Ultrasound. 2016 May;57(3):253-8. doi: 10.1111/vru.12350. Epub 2016 Feb 25.
The sixth cervical vertebra (C6) has unique morphology due to a ventral extension from the transverse process known as the ventral lamina. Little information was found regarding the prevalence and clinical relevance of morphologic variations. Aims of this observational, retrospective study were to characterize C6 morphologic variations in a large sample of horses. Cervical radiographic studies of 100 horses were retrieved. Data recorded were signalment, clinical history, morphology of the C6 ventral lamina, presence of articular process osteoarthritis, and presence of static vertebral canal stenosis. Morphologic variations were found in C6 vertebrae for 24/100 horses, with symmetric absence of the ventral lamina in nine horses and asymmetric absence in 15. Anomalous C6 vertebrae were more common in Warmbloods, with 19/55 Warmbloods in the population being affected (P = 0.006). No association was found with sex. There was no significant difference in the mean of the intravertebral sagittal ratios between horses with normal or anomalous C6 vertebrae; however there was a significantly greater proportion of horses with anomalous C6 vertebrae that had an intravertebral sagittal ratio of less than 0.5 at C6 (P = 0.047). There was no association between the morphology of C6 and articular process osteoarthritis. Anomalous C6 vertebrae in our population were associated with a higher likelihood of cervical pain (P = 0.013). Authors propose that morphologic variations in the C6 ventral laminae could be linked to other developmental abnormalities such as vertebral canal stenosis, might affect regional biomechanics and should therefore be considered clinically relevant in horses. Future, controlled prospective studies are needed to test this theory.
第六颈椎（C6）具有独特的形态，因为其横突有一个腹侧延伸部分，称为腹侧板。关于形态变异的发生率和临床相关性的信息很少。这项观察性、回顾性研究的目的是在大量马匹样本中描述C6的形态变异。检索了100匹马的颈椎X线片研究。记录的数据包括信号、临床病史、C6腹侧板的形态、关节突骨关节炎的存在以及静态椎管狭窄的存在。在100匹马的C6椎体中发现了形态变异，其中9匹马腹侧板对称缺失，15匹马不对称缺失。异常的C6椎体在温血马中更常见，该群体中有19/55的温血马受到影响（P = 0.006）。未发现与性别有关联。C6椎体正常或异常的马匹之间，椎体内矢状比的平均值没有显著差异；然而，C6椎体异常且椎体内矢状比小于0.5的马匹比例显著更高（P = 0.047）。C6的形态与关节突骨关节炎之间没有关联。我们群体中的异常C6椎体与颈部疼痛的可能性更高有关（P = 0.013）。作者提出，C6腹侧板的形态变异可能与其他发育异常如椎管狭窄有关，可能会影响局部生物力学，因此在马匹中应被视为具有临床相关性。未来需要进行对照前瞻性研究来验证这一理论。
