Department of Orthopaedics, Trauma and Plastic Surgery, University of Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany.
Department of Anatomy and Cell Biology, Martin Luther University Halle-Wittenberg, Grosse Steinstrasse 52, 06097, Halle, Saale, Germany.
Sci Rep. 2019 Feb 28;9(1):3141. doi: 10.1038/s41598-019-40052-4.
Sacroiliac (SI) screw loosening may indicate persistent instability, non-union and contribute to pain. Yet, there is no reliable objective measurement technique to detect and monitor SI screw loosening. In 9 cadaveric pelvises one of two SI screw was turned back approximately 20 mm and subsequently assessed by optical measurement, fluoroscopy and a 3D scan using an image intensifier. CTs were segmented and a contour-based registration of the 3D models and the fluoroscopies was performed to measure SI backing out (X-ray module). Three independent observers performed measurements with three repetitions. Deviation of the measurement techniques to the 3D scan, intra- and interrater reliabilities and method equivalence to the 3D scan were assessed. The X-ray module and two fluoroscopic measurement techniques yielded a difference less than 5 mm compared to the 3D scan and equivalence to the 3D scan. Intrarater reliability was for two observers and almost all techniques very good. Three fluoroscopic measurement techniques and optical measurements displayed a very good interrater reliability. The 3D scan and X-ray module yielded the most precise values for SI screw loosening but only the fluoroscopic measurement of the inlet lateral loosening displayed a good reliability and equivalence to the 3D scan.
骶髂（SI）螺钉松动可能表明持续不稳定、不愈合，并导致疼痛。然而，目前还没有可靠的客观测量技术来检测和监测 SI 螺钉松动。在 9 具尸体骨盆中，其中一个 SI 螺钉向后旋转约 20mm，然后通过光学测量、透视和使用影像增强器的 3D 扫描进行评估。对 CT 进行分割，并对 3D 模型和透视图像进行基于轮廓的配准，以测量 SI 螺钉退出（X 射线模块）。三位独立观察者进行了三次重复测量。评估了测量技术与 3D 扫描的偏差、观察者内和观察者间的可靠性以及与 3D 扫描的等效性。X 射线模块和两种透视测量技术与 3D 扫描的差异小于 5mm，与 3D 扫描等效。对于两位观察者和几乎所有技术，观察者内可靠性都非常好。三种透视测量技术和光学测量显示出非常好的观察者间可靠性。3D 扫描和 X 射线模块产生的 SI 螺钉松动值最精确，但只有入口侧松动的透视测量显示出良好的可靠性和与 3D 扫描的等效性。
