Department of Orthopaedics and Sports Medicine, Harborview Medical Center/University of Washington Medical Center, Seattle, WA, USA.
Spine (Phila Pa 1976). 2011 Jun 15;36(14):E936-43. doi: 10.1097/BRS.0b013e3181fdaf06.
Retrospective review of a single tertiary care spine database to identify patients with C2 instrumentation between January 2001 and September 2008.
(1) Evaluate a large series of posterior C2 screws to determine accuracy by computed tomography (CT) scan, (2) assess dimensions of "safe bony windows" with CT, and (3) assess perioperative complication rate related to errant screw placement.
The variable C2 anatomy can make instrumentation challenging and prone to potentially severe complications. New techniques have expanded available options.
Clinical data were obtained from the medical record. Radiographic analyses included preoperative and postoperative CT scans to quantify the patients' bone and to classify accuracy of instrumentation. Screws were graded using the following definitions:
Seven hundred and thirty-six screws in 383 patients were identified. Fifty-five patients were excluded because of lack of data leaving 328 patients (188 male patients, 140 female patients) with 633 screws. Three hundred and thirty-nine pedicle, 154 transarticular, 63 laminar, and 77 short pars screws were placed, and of the 509 screws with postoperative CT scans, accuracy rates (Types I and II) were 98.8%, 98.5%, 100%, and 94.6%, respectively. Eight were unacceptably placed: two medially and six encroaching on the vertebral artery foramen. One patient had a vertebral artery occlusion and another had a dissection. There were no neurologic injuries. Mean CT measurements of pedicle height, axial width, and laminar width were 8.1, 5.8, and 5.7 mm respectively, with males having significantly larger pedicle height (P<0.001), pedicle width (P<0.001), and laminar width (P<0.022).
We show a lower than previously reported incidence of complications associated with posterior C2 screw placement. The multiple techniques of posterior C2 fixation available allow for flexibility in determining ideal technique.
回顾性分析 2001 年 1 月至 2008 年 9 月期间单中心三级脊柱数据库中接受 C2 内固定的患者。
（1）通过 CT 扫描评估大量后路 C2 螺钉的准确性，（2）通过 CT 评估“安全骨窗”的尺寸，（3）评估与螺钉放置错误相关的围手术期并发症发生率。
可变的 C2 解剖结构使得器械的使用具有挑战性，并容易导致潜在的严重并发症。新技术拓宽了可用的选择范围。
临床数据从病历中获取。影像学分析包括术前和术后 CT 扫描，以量化患者的骨骼并对器械的准确性进行分类。螺钉根据以下定义进行分级：
共确定 383 例患者的 736 枚螺钉。55 例患者因资料缺失被排除，共纳入 328 例患者（188 例男性，140 例女性），共 633 枚螺钉。其中 339 枚置入股骨，154 枚置入骨间孔，63 枚置入椎板，509 枚置有术后 CT 扫描的螺钉中，准确性（I 型和 II 型）分别为 98.8%、98.5%、100%和 94.6%。有 8 枚螺钉位置不佳：2 枚向内侧，6 枚向椎动脉孔侵犯。1 例患者发生椎动脉闭塞，1 例发生夹层。无神经损伤。股骨高度、轴向宽度和椎板宽度的平均 CT 测量值分别为 8.1mm、5.8mm 和 5.7mm，男性股骨高度（P<0.001）、宽度（P<0.001）和椎板宽度（P<0.022）显著大于女性。
我们报告了与后路 C2 螺钉放置相关的并发症发生率低于之前的报道。后路 C2 固定的多种技术允许灵活选择理想的技术。
