摘要
目的设计一种采用X线影像资料测量椎弓根螺钉内偏的新方法并评价其诊断价值。方法选取175例患者椎弓根螺钉内固定术后X线和CT影像资料中844枚椎弓根螺钉的图像,3名医师分别采用传统方法和新方法判断螺钉内偏情况。在正位X线片上椎弓根螺钉尖端未超过棘突中线为螺钉非内偏,超过则提示内偏(传统方法)。在侧位X线片上设定螺钉尖端为A点、螺钉头端为B点、螺钉中心轴与椎体后缘交界处为C点,测量AB及AC距离,计算AC与AB的比值r;在正位X线片上设螺钉尖端为A′点、螺钉头端为B′点,测量A′B′长度,以A′B′×r的值作为A′C′长度,则C′点为目标投影点,其代表螺钉刚到达椎体后缘时正位X线片上螺钉尖端的位置;C′点位于椎弓根影内侧缘以外判定螺钉不内偏,位于内侧缘以内则判定螺钉内偏(新方法)。以术后CT检查的评估结果作为金标准,比较采用2种方法观察者间判断一致性及诊断效果的差异。结果新方法判断螺钉内偏情况的观察者间一致性(90.5%,764/844)高于传统方法(71.2%,601/844),差异有统计学意义(P <0.05);新方法诊断灵敏度、特异度、约登指数、阳性似然比、阴性似然比(分别为94.5%、90.2%、0.846、9.62、0.06)均优于传统方法(分别为67.0%、78.0%、0.470、3.04、0.42);新方法对以CT图像评估的螺钉内偏分级0、Ⅰ、Ⅱ、Ⅲ级者检测准确率(分别为90.2%、92.3%、94.7%、100%)均高于传统方法(分别为78.0%、59.0%、73.7%、71.4%),差异有统计学意义(P <0.05)。结论通过正侧位X线影像资料测量判断椎弓根螺钉内偏的方法具有较好的可重复性及诊断价值,值得临床上进一步研究及推广。
Objective To design a new method to judge the internal shifting situations of pedicle screws using roentgenograph,and evaluate its clinical diagnostic value. Methods The roentgenographs of 844 pedicle screws were selected from the postoperative roentgenographs and CTs of 175 patients treated with pedicle screw fixation. Three doctors respectively used 2 different methods to judge internal shifting of pedicle screws using roentgenograph. According to the old method based on anteroposterior roentgenograph,internal shifting of pedicle screws was judged as normal if the tip of the pedicle screw did not exceed the acantha’s center line,and was judged as abnormal if it exceeded the conter line. The new method included several measurement procedures. The screw tip’s projection was set as point A in the lateral roentgenograph,the screw head’s projection as point B,and the junction’s projection of the screw’s center shaft and the vertebral posterior margin as point C. Then the distance of AB and AC as well as the specific value r(AC/AB) were calculated. The screw tip’s projection was set as point A′ in the anteroposterior roentgenograph,and the screw head’s projection being point B′. Through measuring the distance of A′B′ and then multiplying the ratio r,the distance of A′C′ was acquired,then the point C′ was the target projection point,which represented the position of the screw tip on the anteroposterior roentgenograph when the screw just reached the vertebral posterior margin. The judging criteria was established as follows. Internal shifting of pedicle screws was judged as normal if the target projection point located outside the medial margin of the vertebral pedicle,and was judged as abnormal if it located inside the margin. Postoperative CT outcomes which were considered to be the gold standard were compared with the judgments. Intra-observer difference between the 2 groups was analyzed,and clinical diagnostic value was studied. Results Three doctors successfully finished their experimen
作者
卢照应
卢海川
林晓贞
黄春辉
邱永荣
LU Zhao-ying;LU Hai-chuan;LIN Xiao-zhen;HUANG Chun-hui;QIU Yong-rong(Department of Orthopaedics,Longyan First Hospital Affiliated to Fujian Medical University,Longyan 364000,Fujian,China;Department of Operating Room,Longyan First Hospital Affiliated to Fujian Medical University,Longyan 364000,Fujian,China)
出处
《脊柱外科杂志》
2019年第4期262-266,共5页
Journal of Spinal Surgery
基金
福建省龙岩市科技项目（2016LY53）
福建省卫生计生青年科研资助项目（2016-2-59）
关键词
胸椎
腰椎
骨钉
放射摄影影像解释
计算机辅助
Thoracic vertebrae
Lumbar vertebrae
Bone nails
Radiographic image interpretation,computer assisted
