| 摘要: |
| 目的 利用CT及MRI横断面图像行距离及角度测量以评价双侧前路颈椎弓根钉板系统（ACPS）固定的可行性。方法 收集2016年2月至2017年1月于海军总医院行颈椎CT检查且排除骨性畸形的50例男性的下颈椎影像学资料及其中38例的颈椎MRI横断面T2WI图像。在CT骨窗图像上测量最佳进针点距椎体正中线（MVB）的水平距离（DOM）、椎弓根轴线长度（CPA）、椎弓根外宽度（OPW）、同侧实际钉道（AST）长度（根据3.5 mm直径螺钉的螺帽半径为2.25~2.50 mm得出调整后进钉点在同侧距MVB水平距离为-2.5 mm处）、钉道有效宽度（ATW）、椎弓根外倾角（PTA）、钉道外倾角（TTA）。在MRI图像上测量椎动脉-椎弓根距离（DAP）、脊髓-椎弓根距离（DCP）和椎动脉直径（DVA）。结果 任一测量值左、右侧差异均无统计学意义，将同序列同一参数的左、右侧测量数据予以合并进行后续分析。在C3~6，OPW大于ATW、PTA大于TTA（P均<0.05）。以4.5 mm为界，C3、C4、C5、C6分别有20%、18%、17%、8%的OPW及70%、64%、38%、29%的ATW有椎弓根穿破风险。由于DAP和DCP存在，ACPS非严重移位（分别为2.9和4.4 mm）可无临床症状。C7的ATW最小为5.6 mm。结论 使用双侧ACPS时椎弓根穿破率高，非严重穿破时由于DAP和DCP的存在可无临床症状。 |
| 关键词: 下颈椎 X线计算机体层摄影术 磁共振成像 非严重穿破 钉道有效宽度 前路颈椎弓根钉板系统 |
| DOI：10.16781/j.0258-879x.2017.11.1471 |
| 投稿时间：2017-07-30修订日期：2017-10-10 |
| 基金项目:海军总医院创新培育基金（CXPY2014-13）. |
|
| Image measurement of bilateral anterior cervical pedicle screw plate system |
| HOU Li-sheng*,BAI Xue-dong,GE Feng,HE Qing,RUAN Di-ke,LI Hai-feng,CHENG Shi |
(Department of Orthopaedics, Navy General Hospital, Beijing 100048, China
*Corresponding author) |
| Abstract: |
| Objective To evaluate the feasibility of bilateral anterior cervical pedicle screw plate system (ACPS) fixation using liner and angular measurements of subaxial cervical transverse CT and MR images. Methods The images of normal lower cervical vertebrae from 50 males undergoing CT scan of cervical spine from Feb. 2016 to Jan. 2017 in the Naval General Hospital were included, and 38 cervical transverse T2WI images from the above-mentioned males were collected. The distance between optimal entry point and midline of vertebral body (DOM), length of cervical pedicle axis (CPA), outer pedicle width (OPW), actual screw trajectory (AST) at ipsilateral side (adjusted entry point was -2.5 mm away from midline of vertebral body at ipsilateral side, based on the assumption that radius of nut of 3.5 mm diameter pedicle screw was 2.25-2.50 mm), available trajectory width (ATW), pedicle transverse angle (PTA) and trajectory transverse angle (TTA) were measured based on transverse CT images (bone window). The distance between vertebral artery and cervical pedicle (DAP), distance between spinal cord and cervical pedicle (DCP), and diameter of vertebral artery (DVA) were measured based on transverse MR images. Results There were no significant differences in same measurement parameter between left and right sides at same cervical level, and then the left and right measurement data of the same parameter and same sequence were combined for subsequent analysis. The OPW was significantly higher than APW, and PTA was significantly higher than TTA from C3 to C6 (all P<0.05). We defined 4.5 mm width as safety limit for pedicle non-perforation, 20%, 18%, 17%, and 8% of OPW and 70%, 64%, 38% and 29% of APW from C3 to C6 failed to satisfy the criteria. Due to the presence of DAP and DCP, non-critical ACPS displacement (2.9 and 4.4 mm, respectively) might be asymptomatic. The minimum value of ATW at C7 level was 5.6 mm. Conclusion The penetrating rate is high when bilateral ACPS is used in subaxial cervical pedicle, and the non-critical perforation may have no clinical symptoms due to the presence of DAP and DCP. |
| Key words: subaxial cervical vertebrae X-ray computed tomography magnetic resonance imaging non-critical perforation available pedicle width anterior cervical pedicle screw plate system |
