Spine Care Institute, Hospital for Special Surgery, New York, NY.
Spine (Phila Pa 1976). 2022 Feb 1;47(3):E101-E106. doi: 10.1097/BRS.0000000000004137.
Retrospective observational study.
The aim of this study was to investigate the spinal cord safety margins for C2 instrumentation.
Intraoperative spinal cord injury during C2 spine surgery is a rare, but potentially life-threatening complication. Preoperative planning for C2 instrumentation mainly focuses on C2 pedicle bony dimensions on CT and the vertebral artery location and few studies have evaluated C2 spinal cord safety margins.
We measured two distances in C2 bilaterally: C2 pedicle to dura distance (P-D), defined as a transverse line that measured the shortest distance between the medial wall of the C2 pedicle and the dural sac, and C2 pedicle to spinal cord (P-SC), defined as a transverse line that measured the shortest distance between the medial wall of the C2 pedicle and spinal cord. We defined the distances >4 mm as safe for instrumentation.
A total of 146 patients (mean age 71.2, 50.7% female) were included. The average distances were 5.5 mm for C2 left PD, 5.9 mm for C2 right P-D, 10.1 mm for C2 left P-SC, and 10.6 mm for C2 right P-SC. Twenty-eight (21.4%) patients had C2 P-D distances <4 mm and of those two (7%) patients had distances <2 mm. There were more female patients with C2 P-D distances under 4 mm compared to males. No patient had C2 P-SC distances <4 mm.
We demonstrated that around 20% of patients had C2 P-D distance <4 mm, but no patient had C2 P-SC distance <4 mm. Since a lateral misplacement can lead to a potentially fatal vertebral artery injury, medial screw trajectory is recommended for C2 pedicle instrumentation with consideration of these safety margins.Level of Evidence: 3.
回顾性观察研究。
本研究旨在探讨 C2 器械的脊髓安全界限。
C2 脊柱手术过程中发生的脊髓损伤虽然罕见，但可能危及生命。C2 器械的术前规划主要集中在 CT 上的 C2 椎弓根骨尺寸和椎动脉位置上，很少有研究评估 C2 脊髓安全界限。
我们在 C2 双侧测量了两个距离：C2 椎弓根至硬脑膜距离（P-D），定义为一条测量 C2 椎弓根内缘与硬脑膜之间最短距离的横切线；C2 椎弓根至脊髓距离（P-SC），定义为一条测量 C2 椎弓根内缘与脊髓之间最短距离的横切线。我们将距离>4mm 定义为器械安全。
共纳入 146 例患者（平均年龄 71.2 岁，50.7%为女性）。平均 C2 左侧 PD 为 5.5mm，C2 右侧 P-D 为 5.9mm，C2 左侧 P-SC 为 10.1mm，C2 右侧 P-SC 为 10.6mm。28 例（21.4%）患者的 C2 P-D 距离<4mm，其中 2 例（7%）患者的距离<2mm。与男性相比，更多女性患者的 C2 P-D 距离小于 4mm。没有患者的 C2 P-SC 距离<4mm。
我们表明，大约 20%的患者的 C2 P-D 距离<4mm，但没有患者的 C2 P-SC 距离<4mm。由于外侧放置可能导致潜在致命的椎动脉损伤，因此建议在考虑这些安全界限的情况下，对 C2 椎弓根进行内侧螺钉轨迹器械。
3 级。
