Ma Hao-Ning, Liu Chu-Yin, Jiang Liang-Hai, Yi Ping, Yang Feng, Tang Xiang-Sheng, Tan Ming-Sheng
Department of Spinal Surgery, China Japan Friendship Hospital, Beijing 100029, China;
Zhongguo Gu Shang. 2016 Oct 25;29(10):903-909. doi: 10.3969/j.issn.1003-0034.2016.10.007.
To investigate the meaning of pedicle exposure technique for screw fixation on atlas with the vertebral groove height less than 4 mm by using reconstructive computed tomography.
From April 2015 to June 2015, 84 pedicles of 51 patients with groove heights less than 4 mm were studied by digital reconstruction respectively. Parameters of atlas pedicle screw fixation were measured.
Among the 51 cases, the vertebral groove height was (3.28±0.51) mm. Lateral mass heights, lateral mass widths and the transition area heights between lateral mass and posterior arch were fit for 3.5 mm screw implanting. Ideal pedicle screw trajectory lengths from 0° to 15° (0°, 5°, 10°, 15°) were (27.36±1.81), (27.01±1.68), (27.07±1.75), (27.48±1.72) mm, exposed trajectory lengths from 0° to 15°(0°, 5°, 10°, 15°) were(23.44±1.79), (23.87±1.84), (24.58±1.89), (25.56±2.01) mm, trajectory length of lateral mass was (20.78±2.05) mm. The mean CT values on 5 sections through pedicle trajectory and lateral mass trajectory were (701.89±141.48) HU and (599.11±137.33) HU, respectively. There were no significant differences between ideal pedicle trajectory lengths from 0° to 15°(>0.05). Exposed trajectory lengths was significantly increased accompanying with medial angles increasing (<0.05), and was longer than trajectory lengths of lateral mass (<0.05). CT value of pedicle screws was higher than CT value of lateral mass screws significantly (<0.01).
Screws can be implanted in atlas with vertebral groove height less than 4 mm by using pedicle exposure technique. Few trajectory lengths will be sacrificed with favorable pull out strength due to adequate bone mass purchased.
采用重建计算机断层扫描技术，探讨椎弓根显露技术在寰椎椎弓根螺钉固定中对椎弓根沟高度小于4mm的意义。
2015年4月至2015年6月，对51例椎弓根沟高度小于4mm患者的84个椎弓根分别进行数字重建，测量寰椎椎弓根螺钉固定参数。
51例患者中，椎弓根沟高度为（3.28±0.51）mm。侧块高度、侧块宽度及侧块与后弓之间的过渡区高度适合植入3.5mm螺钉。0°至15°（0°、5°、10°、15°）理想椎弓根螺钉轨迹长度分别为（27.36±1.81）、（27.01±1.68）、（27.07±1.75）、（27.48±1.72）mm，0°至15°（0°、5°、10°、15°）显露轨迹长度分别为（23.44±1.79）、（23.87±1.84）、（24.58±1.89）、（25.56±2.01）mm，侧块轨迹长度为（20.78±2.05）mm。通过椎弓根轨迹和侧块轨迹的5个层面的平均CT值分别为（701.89±141.48）HU和（599.11±137.33）HU。0°至15°理想椎弓根轨迹长度之间差异无统计学意义（>0.05）。显露轨迹长度随内倾角增加而显著增加（<0.05），且长于侧块轨迹长度（<0.05）。椎弓根螺钉的CT值显著高于侧块螺钉的CT值（<0.01）。
采用椎弓根显露技术可在椎弓根沟高度小于4mm的寰椎植入螺钉。由于获得了足够的骨质，牺牲的轨迹长度较少，且拔出强度良好。
