King Nicolas K K, Rajendra Tiruchelvarayan, Ng Ivan, Ng Wai Hoe
Department of Neurosurgery, National Neuroscience Institute, Singapore General Hospital, Outram Road, Singapore 169608.
National Neuroscience Institute, Singapore General Hospital, Outram Road, Singapore 169608 and Gleneagles Hospital, Napier Road, Singapore 258500.
Surg Neurol Int. 2014 Aug 28;5(Suppl 7):S380-3. doi: 10.4103/2152-7806.139676. eCollection 2014.
Occipital-cervical fusion (OCF) has been used to treat instability of the occipito-cervical junction and to provide biomechanical stability after decompressive surgery. The specific areas that require detailed morphologic knowledge to prevent technical failures are the thickness of the occipital bone and diameter of the C2 pedicle, as the occipital midline bone and the C2 pedicle have structurally the strongest bone to provide the biomechanical purchase for cranio-cervical instrumentation. The aim of this study was to perform a quantitative morphometric analysis using computed tomography (CT) to determine the variability of the occipital bone thickness and C2 pedicle thickness to optimize screw placement for OCF in a South East Asian population.
Thirty patients undergoing cranio-cervical junction instrumentation during the period 2008-2010 were included. The thickness of the occipital bone and the length and diameter of the C2 pedicle were measured based on CT.
The thickest point on the occipital bone was in the midline with a maximum thickness below the external occipital protuberance of 16.2 mm (±3.0 mm), which was thicker than in the Western population. The average C2 pedicle diameter was 5.3 mm (±2.0 mm). This was smaller than Western population pedicle diameters. The average length of the both pedicles to the midpoint of the C2 vertebral body was 23.5 mm (±3.3 mm on the left and ±2.3 mm on the right).
The results of this first study in the South East Asian population should help guide and improve the safety in occipito-cervical region instrumentation. Thus reducing the risk of technical failures and neuro-vascular injury.
枕颈融合术（OCF）已被用于治疗枕颈交界区不稳，并在减压手术后提供生物力学稳定性。枕骨厚度和C2椎弓根直径是预防技术失败所需详细形态学知识的特定区域，因为枕骨中线骨和C2椎弓根在结构上具有最强的骨，可为颅颈器械提供生物力学支撑。本研究的目的是使用计算机断层扫描（CT）进行定量形态学分析，以确定枕骨厚度和C2椎弓根厚度的变异性，从而优化东南亚人群OCF的螺钉置入。
纳入2008年至2010年期间接受颅颈交界区器械置入的30例患者。根据CT测量枕骨厚度以及C2椎弓根的长度和直径。
枕骨最厚点位于中线，枕外隆突下方的最大厚度为16.2 mm（±3.0 mm），比西方人群厚。C2椎弓根平均直径为5.3 mm（±2.0 mm）。这比西方人群的椎弓根直径小。两侧椎弓根至C2椎体中点的平均长度为23.5 mm（左侧±3.3 mm，右侧±2.3 mm）。
这项针对东南亚人群的首次研究结果应有助于指导和提高枕颈区器械置入的安全性。从而降低技术失败和神经血管损伤的风险。
