Li Bo, Qiu Guixing, Guo Shigong, Li Wenjing, Li Ye, Peng Huiming, Wang Chu, Zhao Yu
Department of Orthopaedic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Department of Trauma & Orthopaedic Surgery, Hillingdon Hospital, London, UK.
BMJ Open. 2016 Dec 20;6(12):e013887. doi: 10.1136/bmjopen-2016-013887.
To investigate the incidence, distribution and radiological characteristics of dural ossification (DO) associated with ossification of ligamentum flavum (OLF) in the thoracic spine.
A retrospective radiographical analysis.
This study was conducted at a single institution in China.
53 patients with OLF who underwent posterior decompression surgery between January 2011 and July 2015 in a single institution were enrolled in this study. The decompression segments were grouped according to imaging evaluation and intraoperative evidences.
The demographic distribution, radiological data and detailed surgical records were collected. First, preoperative CT images of decompressed segments were evaluated to identify imaging signs of DO. The 'tram tack sign' (TTS), 'comma sign' and 'bridge sign' were considered as characteristic imaging findings of DO in OLF. 4 kinds of confusing signs (false TTS) were identified and excluded. Then detailed surgical records were reviewed to finally identify segments with DO.
The incidence of DO in patients with OLF was 43.4%. The incidence of DO in OLF segments was 21.5%. OLF was more common in the lower thoracic spine, and more than half (53.8%) of the DO was located in T9-T12. TTS was the most common sign, but it might be misdiagnosed. After excluding 4 kinds of false TTS, the sensitivity and specificity of imaging diagnosis were 94.23% and 94.21%, respectively.
DO was relatively common in thoracic OLF, especially in T9-T12. TTS might be misdiagnosed. After excluding 4 kinds of false TTS, the accuracy of imaging diagnosis was relatively high.
探讨胸椎黄韧带骨化（OLF）合并硬脊膜骨化（DO）的发生率、分布情况及影像学特征。
一项回顾性影像学分析。
本研究在中国的一家单一机构进行。
选取2011年1月至2015年7月在该单一机构接受后路减压手术的53例OLF患者纳入本研究。根据影像学评估和术中证据对减压节段进行分组。
收集人口统计学分布、影像学数据和详细的手术记录。首先，评估减压节段的术前CT图像以识别DO的影像学征象。“轨道钉征”（TTS）、“逗号征”和“桥征”被视为OLF中DO的特征性影像学表现。识别并排除4种易混淆征象（假TTS）。然后回顾详细的手术记录以最终确定存在DO的节段。
OLF患者中DO的发生率为43.4%。OLF节段中DO的发生率为21.5%。OLF在下胸椎更为常见，超过一半（53.8%）的DO位于T9 - T12。TTS是最常见的征象，但可能被误诊。排除4种假TTS后，影像学诊断的敏感性和特异性分别为94.23%和94.21%。
DO在胸椎OLF中相对常见，尤其是在T9 - T12。TTS可能被误诊。排除4种假TTS后，影像学诊断的准确性相对较高。
