Batista Ulysses C, Joaquim Andrei F, Fernandes Yvens B, Mathias Roger N, Ghizoni Enrico, Tedeschi Helder
Department of Neurology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
Neurosurg Focus. 2015 Apr;38(4):E5. doi: 10.3171/2015.1.FOCUS14642.
Most of the craniometric relationships of the normal craniocervical junction (CCJ), especially those related to angular craniometry, are still poorly studied and based on measurements taken from simple plain radiographs. In this study, the authors performed a craniometric evaluation of the CCJ in a population without known CCJ anomalies. The purpose of the study was to evaluate the normal CCJ craniometry based on measurements obtained from CT scans.
The authors analyzed 100 consecutive CCJ CT scans obtained in adult patients who were admitted at their tertiary hospital for treatment of non-CCJ conditions between 2010 and 2012. A total of 17 craniometrical measurements were performed, including the relation of the odontoid with the cranial base, the atlantodental interval (ADI), the clivus length, the clivus-canal angle (CCA)-the angle formed by the clivus and the upper cervical spine, and the basal angle.
The mean age of the 100 patients was 50.6 years, and the group included 52 men (52%) and 48 women (48%). In 5 patients (5%), the tip of the odontoid process was more than 2 mm above the Chamberlain line, and in one of these 5 patients (1% of the study group). it was more than 5 mm above it. One patient had a Grabb-Oakes measurement above 9 mm (suggesting ventral cervicomedullary encroachment). The mean ADI value was 1.1 mm. The thickness of the external occipital protuberance ranged from 7.42 to 22.36 mm. The mean clivus length was 44.74 mm, the mean CCA was 153.68° (range 132.32°-173.95°), and the mean basal angle was 113.73° (ranging from 97.06°-133.26°).
The data obtained in this study can be useful for evaluating anomalies of the CCJ in comparison with normal parameters, potentially improving the diagnostic criteria of these anomalies. When evaluating CCJ malformations, one should take into account the normal ranges based on CT scans, with more precise bone landmarks, instead of those obtained from simple plain radiographs.
正常颅颈交界区（CCJ）的大多数颅骨测量关系，尤其是那些与角度颅骨测量相关的关系，仍研究不足，且基于简单平片的测量。在本研究中，作者对一组无已知CCJ异常的人群进行了CCJ的颅骨测量评估。本研究的目的是基于CT扫描获得的测量值评估正常CCJ的颅骨测量。
作者分析了2010年至2012年间在其三级医院因非CCJ疾病入院治疗的成年患者连续100例CCJ的CT扫描。共进行了17项颅骨测量，包括齿突与颅底的关系、寰齿间距（ADI）、斜坡长度、斜坡-椎管角（CCA）——斜坡与上颈椎形成的角度，以及基底角。
100例患者的平均年龄为50.6岁，该组包括52名男性（52%）和48名女性（48%）。5例患者（5%）齿突尖高于钱伯林线2mm以上，其中1例（占研究组的1%）高于该线5mm以上。1例患者的格拉布-奥克斯测量值超过9mm（提示腹侧颈髓受压）。平均ADI值为1.1mm。枕外隆凸厚度在7.42至22.36mm之间。平均斜坡长度为44.74mm，平均CCA为153.68°（范围132.32°-173.95°），平均基底角为113.73°（范围97.06°-133.26°）。
本研究获得的数据与正常参数相比，可用于评估CCJ异常，可能改善这些异常的诊断标准。在评估CCJ畸形时，应考虑基于CT扫描的正常范围，其具有更精确的骨标志，而非简单平片获得的范围。
