Wajanavisit Wiwat, Lertudomphonwanit Thamrong, Fuangfa Praman, Chanplakorn Pongsthorn, Kraiwattanapong Chaiwat, Jaovisidha Supaneewan
Department of Orthopedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Department of Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
Asian Spine J. 2016 Dec;10(6):1141-1148. doi: 10.4184/asj.2016.10.6.1141. Epub 2016 Dec 8.
Cross-sectional, matched-pair comparative study.
To determine whether a thin-sliced pedicular-oriented computed tomography (TPCT) scan reconstructed from an existing conventional computed tomography (CCT) scan is more accurate for identifying vertebral artery groove (VAG) anomalies than CCT.
Posterior atlantoaxial transarticular screw fixation and C2 pedicle screws can cause vertebral artery (VA) injury. Two anatomic variations of VAG anomalies are associated with VA injury: a high-riding VA (HRVA) and a narrow pedicle of the C2 vertebra. CCT scan is a reliable method used to evaluate VAG anomalies; however, its accuracy level remains debatable. Literature comparing the prevalence of C2 VAG anomalies between CCT and TPCT is limited.
A total of 200 computed tomography scans of the upper cervical spine obtained between January 2008 and December 2011 were evaluated for C2 VAG anomalies (HRVA and narrow pedicular width) using CCT and TPCT. The prevalence of C2 VAG anomalies was compared using these two different measurement methods via a McNemar's test.
Of the 200 patients studied, 23 HRVA (6.01%; 95% confidence interval [CI], 3.61%-8.39%) were detected with CCT, whereas 66 HRVA (16.54%; 95% CI, 12.85%-20.23%) were detected with TPCT (<0.001). Sixty-two narrow pedicles (15.58%; 95% CI, 11.99%-19.15%) were detected with CCT, whereas 90 narrow pedicles (22.83%; 95% CI, 18.58%-26.87%) were detected with TPCT (<0.001).
VAG anomalies are commonly observed. A preoperative evaluation using TPCT reconstructed from an existing CCT revealed a significantly higher prevalence of C2 VAG anomalies than did CCT and showed comparable prevalence to previously published studies using more sophisticated and higher risk techniques. Therefore, we propose TPCT as an alternative preoperative evaluation for C2 screw placement and trajectory planning.
横断面配对比较研究。
确定从现有的传统计算机断层扫描（CCT）重建的薄层椎弓根定向计算机断层扫描（TPCT）在识别椎动脉沟（VAG）异常方面是否比CCT更准确。
寰枢椎后路经关节螺钉固定和C2椎弓根螺钉可导致椎动脉（VA）损伤。VAG异常的两种解剖变异与VA损伤有关：高位椎动脉（HRVA）和C2椎骨椎弓根狭窄。CCT扫描是用于评估VAG异常的可靠方法；然而，其准确性水平仍存在争议。比较CCT和TPCT之间C2 VAG异常患病率的文献有限。
对2008年1月至2011年12月期间获得的200例上颈椎计算机断层扫描进行评估，使用CCT和TPCT检测C2 VAG异常（HRVA和椎弓根宽度狭窄）。通过McNemar检验使用这两种不同的测量方法比较C2 VAG异常的患病率。
在研究的200例患者中，CCT检测到23例HRVA（6.01%；95%置信区间[CI]，3.61%-8.39%），而TPCT检测到66例HRVA（16.54%；95%CI，12.85%-20.23%）（P<0.001）。CCT检测到62例椎弓根狭窄（15.58%；9%CI，11.99%-19.15%），而TPCT检测到90例椎弓根狭窄（22.83%；95%CI，18.58%-26.87%）（P<0.001）。
VAG异常常见。使用从现有CCT重建的TPCT进行术前评估显示，C2 VAG异常的患病率明显高于CCT，并且与使用更复杂和更高风险技术的先前发表的研究显示的患病率相当。因此，我们建议将TPCT作为C2螺钉置入和轨迹规划的替代术前评估方法。
