Spine Division, University Hospital Balgrist, University of Zürich, Switzerland.
Department of Radiology, University Hospital Balgrist, University of Zürich, Switzerland.
Spine J. 2019 Mar;19(3):461-468. doi: 10.1016/j.spinee.2018.06.345. Epub 2018 Jun 26.
Pedicle screw loosening is common after spinal fusion and can be associated with pseudoarthrosis and pain. With suspicion of screw loosening on standard radiographs, CT is currently considered the advanced imaging modality of choice. MRI with new metal artifact reduction techniques holds potential to be sensitive in detection of screw loosening. The sensitivity and specificity of either of the imaging modalities are yet clear.
To evaluate the sensitivity and specificity of three different image modalities (standard radiographs, CT, and MRI) for detection of pedicle screw loosening.
STUDY DESIGN/SETTING: Cross-sectional diagnostic study.
Forty-one patients (159 pedicle screws) undergoing revision surgeries after lumbar spinal fusion between August 2014 and April 2017 with preoperative radiographs, CT, and MRI with spinal metal artifact reduction (STIR WARP and TSE high bandwidth sequences).
Sensitivity and specificity in detection of screw loosening for each imaging modality.
Screw torque force was measured intraoperatively and compared with preoperative screw loosening signs such as peri-screw edema in MRI and peri-screw osteolysis in CT and radiographs. A torque force of less than 60 Ncm was used to define a screw as loosened.
Sensitivity and specificity in detection of screw loosening was 43.9% and 92.1% for MRI, 64.8% and 96.7% for CT, and 54.2% and 83.5% for standard radiographs, respectively.
Despite improvement of MRI with metal artifact reduction MRI technique, CT remains the modality of choice. Even so, CT fails to detect all loosened pedicle screws.
脊柱融合术后椎弓根螺钉松动较为常见，可并发假关节形成和疼痛。标准 X 线片怀疑螺钉松动时，目前 CT 被认为是首选的高级影像学检查方法。具有新型金属伪影降低技术的 MRI 有可能在检测螺钉松动方面具有敏感性。但两种影像学方法的敏感性和特异性尚不清楚。
评估三种不同影像学方法（标准 X 线片、CT 和 MRI）检测椎弓根螺钉松动的敏感性和特异性。
研究设计/设置：横断面诊断研究。
2014 年 8 月至 2017 年 4 月期间因腰椎融合术后行翻修手术的 41 例患者（159 枚椎弓根螺钉），术前有 X 线片、CT 和 MRI（具有脊柱金属伪影降低技术的 STIR WARP 和 TSE 高带宽序列）。
每种影像学方法检测螺钉松动的敏感性和特异性。
术中测量螺钉的扭矩力，并与 MRI 中的螺钉周围水肿和 CT 及 X 线片中的螺钉周围溶骨性改变等术前螺钉松动征象进行比较。将扭矩力小于 60 Ncm 的螺钉定义为松动螺钉。
MRI 检测螺钉松动的敏感性和特异性分别为 43.9%和 92.1%，CT 为 64.8%和 96.7%，标准 X 线片为 54.2%和 83.5%。
尽管具有金属伪影降低技术的 MRI 有所改善，但 CT 仍是首选的影像学检查方法。即便如此，CT 也未能检测到所有松动的椎弓根螺钉。
