摘要
目的通过术中对椎弓根多维透视结果进行比较,探索一种简洁易行的透视角度,减少术中椎弓根钉误置率。方法取8具成年人新鲜L1-5椎骨标本,随机建立偏内、偏外、居中3种模型。分别置入导针和椎弓根钉,依次透视侧位、正位、椎弓根轴位、导针轴位、椎弓根钉轴位。根据导针和椎弓根钉与椎弓根投影的相互位置关系判断导针和椎弓根钉位置。术后CT扫描椎弓根钉道,观察椎弓根内外侧皮质穿透情况。切除椎板直视观察结果作为金标准。结果正位透视准确率为34%。侧位透视不能判断偏内及偏外错误。椎弓根轴位透视误将4枚居中判为偏内,准确率为95%。导针轴位透视准确率为100%。结论导针轴位透视能准确判断椎弓根钉导针位置,可提高置钉准确率,减少椎弓根钉松动的人为因素。
Objectives To develop an applicable and accurate intra-operative fluoroscopical angle to observe the placement of pedicle screw and pedicle violation. Methods Lateral radiographs were taken on eighty lumbar pedicles in eight cadaveric vertebral specimens to measure the sagittal pedicle angles. The pedicles of the vertebral arch were scanned by computed tomography （CT） to measure the transverse pedicle angles. Guided pins and pedicle screws were inserted by awl into the pedicles through the holes drilled in the lumbar pedicles so as to establish 3 types of model ： medial violation （ n=29）, lateral violation （ n=25 ）, and properly placed screw （n=26） the anterior and posterior portions of the lumbar pedicle cortex could be identified by the fluoroscopy C-arm. Fluoroscopy with the aid of C-arm was taken on each pedicle in five different directions： lateral position; anteroposterior position; pedicle axial position; guided pin axial position; and pedicle screw axial position. The positions of guided pin and pedicle screw were evaluated, The gold standard was acquired by excising the vertebral plate and observing directly. Results Nine cases of medial violation were discovered and the accuracy rate was 33.75% by anteroposterior fluoroscopy. The accuracy rate was 95% by the pedicle axial fluoroscopes, including 4 cases of medial inclination but properly placed screws were mistaken for medial violation by pedicle axial fluoroscope. The accuracy rate was 100% by guided pin axial position fluoroscopy, including 29 cases of medial violations, 25 cases of lateral violation, and 26 cases of properly placed screws. Conclusion The approach of intra-operative fluoroscopy of guided pin axial position is a reliable technology for detecting pedicle violation with the aid of C-arm. The incidence of flexible pedicle screw from human factors can be reduced.
出处
《中华医学杂志》
CAS
CSCD
北大核心
2006年第19期1309-1312,共4页
National Medical Journal of China
