Neurosurgery Service, Walter Reed Army Medical Center, Washington, DC 20307, USA.
Spine J. 2010 Oct;10(10):905-9. doi: 10.1016/j.spinee.2010.08.020.
Pedicle screw placement in the proximal thoracic spine may result in unwanted bicortical breach. An understanding of the potential structures at risk is paramount to safe screw placement.
To assess the anatomic location of structures at risk with the placement of bicortical pedicle screw fixation in the proximal thoracic spine.
Retrospective radiographic review.
Twenty patients with dedicated computed tomography (CT) scans of the thoracic spine.
Radiographic parameters on CT.
Computed tomography was performed on 20 patients and analyzed from T1 to T4 for proximity of major structures at risk with breach of the anterior vertebral body cortex from pedicle screw placement. Descriptive statistics, analyses of variance and post hoc paired t tests were used to analyze screw position relative to the esophagus, trachea, aortic arch, carotid, and vertebral arteries.
One hundred sixty potential anterior cortical violation positions were analyzed. Left-sided pedicle screws posed a significantly higher risk (p<.05) to the esophagus at T1-T3; in particular, the left T2 screw was significantly closer (p<.05). Right-sided pedicle screws posed a significantly higher risk to the trachea at T2-T4 (p<.05). The right T3 and T4 screws posed the greatest risk to the trachea and right main bronchus, respectively (p<.05). The carotid and vertebral arteries were not at risk for injury. The aortic arch was present at T4 in 70% of patients and was not at risk.
Careful preoperative evaluation with CT is warranted to determine anatomic structures at risk when placing proximal thoracic pedicle screws. Left-sided screws pose the greatest risk to the esophagus; right-sided screws pose the greatest risk to the trachea. The carotid and vertebral arteries, along with the aortic arch are at minimal risk for injury.
在胸上段脊柱中置入椎弓根螺钉可能导致不必要的双皮质穿透。了解潜在的危险结构对于安全置钉至关重要。
评估胸上段脊柱双侧皮质椎弓根螺钉固定时潜在危险结构的解剖位置。
回顾性放射学研究。
20 例接受胸椎专用 CT 扫描的患者。
CT 影像学参数。
对 20 例患者进行 CT 检查，并对 T1 至 T4 进行分析，以确定椎弓根螺钉穿透前椎体皮质时主要危险结构的毗邻关系。采用描述性统计学、方差分析和事后配对 t 检验分析螺钉位置与食管、气管、主动脉弓、颈动脉和椎动脉的关系。
分析了 160 个潜在的前皮质穿透位置。左侧椎弓根螺钉在 T1-T3 段对食管的风险明显更高（p<.05），特别是左侧 T2 螺钉明显更接近（p<.05）。右侧椎弓根螺钉在 T2-T4 段对气管的风险明显更高（p<.05）。右侧 T3 和 T4 螺钉分别对气管和右主支气管构成最大风险（p<.05）。颈动脉和椎动脉没有受伤的风险。主动脉弓在 70%的患者中存在于 T4 段，没有风险。
在胸上段置入椎弓根螺钉时，需要进行仔细的术前 CT 评估，以确定潜在的危险结构。左侧螺钉对食管构成最大风险，右侧螺钉对气管构成最大风险。颈动脉和椎动脉以及主动脉弓受伤风险较小。
