Department of Orthopaedics and Sports Medicine, Harborview Medical Center, University of Washington School of Medicine, Seattle, WA 98104, USA.
Spine J. 2012 Mar;12(3):231-8. doi: 10.1016/j.spinee.2012.02.011. Epub 2012 Mar 3.
The variable C1 anatomy can make instrumentation challenging and prone to potentially severe complications. New techniques have expanded available options.
The aims of this study were to evaluate a large series of posterior C1 screws to determine accuracy by computed tomography (CT) scan; assess dimensions of "safe bony windows" with CT; and assess perioperative complication rate related to errant screw placement.
Retrospective review of a single tertiary care spine database to identify patients with C1 instrumentation between December 2002 and September 2008.
The sample comprised 176 patients with 344 C1 screws. All 176 patients were assessed for perioperative complications related to their C1 screws. Twenty-nine patients did not have postoperative CT scans, leaving 147 patients with 286 screws for analysis of screw accuracy.
The outcome measures consisted of a radiographic assessment of accuracy of placement of C1 instrumentation and a clinical assessment of perioperative complications related to C1 instrumentation focusing on neurologic and vascular injuries.
Clinical data were obtained from the medical record. Radiographic analyses included preoperative and postoperative CT scans to quantify the patients' bone and classify accuracy of instrumentation. Screws were graded using the following definitions: Type I, screw threads completely within the bone; Type II, less than half the diameter of the screw violates the surrounding cortex; and Type III, clear violation of transverse foramen or spinal canal.
One hundred seventy-six patients (97 males and 79 females) underwent posterior C1 screw (lateral mass [LM] or transarticular [TA]) fixation. A total of 344 screws were placed with 216 LM screws and 128 TA screws. Twenty-nine patients (58 screws) did not have postoperative CT scans and were not included for analysis of radiographic accuracy but were included in assessment of complications based on medical records. Ninety-six percent of screws (Type I or II) were rated as "safe," and 86% of screws were rated as being ideal (Type I). Twelve screws (4%) were unacceptably placed (Type III). There were no known neurologic or vertebral artery injuries. One patient underwent revision surgery for a medially placed screw. Mean C1 LM width was 10.5 mm across all patients. Estimated blood loss averaged 331 mL.
Our findings demonstrate a low incidence of complications associated with posterior screw instrumentation of the C1 LM.
C1 解剖结构多变，使得器械操作具有挑战性，并容易导致潜在的严重并发症。新的技术已经扩展了可用的选择。
本研究的目的是通过计算机断层扫描（CT）评估大量后路 C1 螺钉以确定准确性；通过 CT 评估“安全骨窗”的尺寸；并评估与螺钉放置错误相关的围手术期并发症发生率。
回顾性分析 2002 年 12 月至 2008 年 9 月期间单中心三级护理脊柱数据库中接受 C1 器械治疗的患者。
样本包括 176 例患者，共 344 枚 C1 螺钉。对所有 176 例患者进行了与 C1 螺钉相关的围手术期并发症评估。29 例患者未行术后 CT 扫描，因此 147 例患者中有 286 枚螺钉用于螺钉准确性的分析。
C1 器械准确性的影像学评估和与 C1 器械相关的围手术期并发症的临床评估，重点是神经和血管损伤。
从病历中获得临床数据。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：Ⅰ型，螺钉螺纹完全在骨内；Ⅱ型，不到螺钉直径的一半侵犯周围皮质；Ⅲ型，明显侵犯横突孔或椎管。
176 例患者（97 例男性和 79 例女性）接受了后路 C1 螺钉（侧块[LM]或关节突间[T A]）固定。共放置 344 枚螺钉，其中 216 枚 LM 螺钉和 128 枚 TA 螺钉。29 例患者（58 枚螺钉）未行术后 CT 扫描，未纳入影像学准确性分析，但根据病历纳入并发症评估。96%的螺钉（Ⅰ型或Ⅱ型）被评为“安全”，86%的螺钉被评为理想（Ⅰ型）。12 枚螺钉（4%）被认为放置不当（Ⅲ型）。没有已知的神经或椎动脉损伤。1 例患者因内侧放置的螺钉行翻修手术。所有患者的 C1 LM 平均宽度为 10.5 毫米。平均估计失血量为 331 毫升。
我们的研究结果表明，后路 C1 LM 螺钉固定相关并发症发生率较低。
