Cleveland Clinic Center for Spine Health, Cleveland Clinic, Cleveland, OH 44195, USA.
Spine (Phila Pa 1976). 2012 May 20;37(12):E745-51. doi: 10.1097/BRS.0b013e31824c70ef.
Morphometric and volumetric analyses and virtual screw placement.
The aim of the study was to (1) define the morphometric and volumetric dimensions of the laminae of C3-C7 and (2) analyze the feasibility of unilateral and bilateral translaminar screw placement at C3-C7.
Previous studies on translaminar screw fixation have primarily focused on upper cervical and thoracic fixation. Most studies have been conducted on the subaxial cervical vertebrae in the pediatric population and a few in the adult population. In this study, we used computed tomographic (CT) scans to calculate the spatial anatomical environment for translaminar screws at C3-C7. We also determined the feasibility of translaminar screw placement at C3-C7 for clinical applicability.
Morphometric and volumetric analyses were performed on CT scans of the C3-C7 laminae in 25 male and 25 female patients. A total of 2000 morphometric and 1000 volumetric measurements were performed. The feasibility analysis was performed using unilateral and bilateral virtual screw placement via BrainLAB software (BrainLAB AG, Heimstetten, Germany) on the same CT scans.
Male patients had significantly (P < 0.05) longer translaminar lengths (C5-C7), sagittal-diagonal measurements (C3-C7), and larger volumes (C6-C7) than female patients. Unilaterally, C7 showed 3.5-mm translaminar screw acceptance rates of 100%, C6 showed high acceptance rates (>64%), and C3-C5 showed lower acceptance rates (<52%). C7 accepted bilateral placement at a high rate (96% men, 84% women). C3 and C6 accepted bilateral screws at low placement rates (8%-24%). C4 and C5 never accepted bilateral translaminar screw placement.
Subaxial cervical unilateral translaminar screw placement is a potentially safe and effective technique to use in conjunction with preoperative CT scanning for all vertebral levels. The same is true for bilateral placement at C7 but not at C3-C6. A prospective study to evaluate the long-term outcomes of translaminar fixation at all vertebral levels is currently underway.
形态计量学和体积分析以及虚拟螺钉放置。
本研究的目的是：(1) 定义 C3-C7 椎板的形态计量学和体积尺寸；(2) 分析 C3-C7 单侧和双侧经椎板螺钉放置的可行性。
先前关于经椎板螺钉固定的研究主要集中在上颈椎和胸段固定。大多数研究都是在儿童人群的下颈椎进行的，少数研究是在成人人群中进行的。在这项研究中，我们使用计算机断层扫描（CT）扫描来计算 C3-C7 经椎板螺钉的空间解剖环境。我们还确定了 C3-C7 经椎板螺钉放置的可行性，以实现临床适用性。
对 25 名男性和 25 名女性患者的 C3-C7 椎板进行形态计量学和体积分析。共进行了 2000 次形态计量学和 1000 次体积测量。使用 BrainLAB 软件（德国 BrainLAB AG）在同一 CT 扫描上进行单侧和双侧虚拟螺钉放置的可行性分析。
男性患者的经椎板长度（C5-C7）、矢状对角线测量值（C3-C7）和体积（C6-C7）明显长于女性患者（P<0.05）。单侧 C7 的经椎板螺钉接受率为 100%，C6 的接受率较高（>64%），C3-C5 的接受率较低（<52%）。C7 双侧放置的接受率较高（男性 96%，女性 84%）。C3 和 C6 双侧螺钉放置的接受率较低（8%-24%）。C4 和 C5 从不接受双侧经椎板螺钉放置。
下颈椎单侧经椎板螺钉放置是一种安全有效的技术，可与术前 CT 扫描结合使用，适用于所有椎体水平。C7 双侧放置也是如此，但 C3-C6 则不然。目前正在进行一项前瞻性研究，以评估所有椎体水平经椎板固定的长期结果。
