Digital analysis and application of screw insertion pathway for S1 transverse sacroiliac screw fixation
ZHANG Yuanzhi
WANG Junqiang
ZHAO Jianmin
LU Quanli
LI Yaguang
JIA Yanfei
Abstract：Objective To investigate the determination of safe pathway of screw insertion for S1 transverse sacroiliac screw fixation, and to explore their application values in the treatment of longitudinal fracture of the sacrum. Methods Fifty healthy adult volunteers received abdominal continuous spiral CT scanning, 3D surface reconstruction, standard sacral sagittal multi-layer triangulation, and then an optimal screw channel was generated. The digital analysis results were subsequently applied in 18 patients with sacral longitudinal fracture, who were treated by S1 transverse sacroiliac screw fixation from August 2012 to August 2013 in the Affiliated Hospital of Inner Mongolia Medical University, which the screw insertion pathway was determined by intraoperative CT sagittal image projection on sacrum. Results Sagittal projection of X-ray on S1 vertebral body displayed the safety area was oval, and the intersection of long and short axial lines of projection for S1 vertebrae was the optimal screw channel. The average length of the channel was (135 ± 8) mm. Lag screw (7.3 mm diameter) insertion was simulated, and the position and length of the sacroiliac screw showed well. Postoperative X-ray and CT scan images also confirmed that the screw insertion position and length were well satisfied, with the average length of screw was (115 ± 4) mm, the average operation time was (30 ± 5) min. All patients were followed up for 12 to 24 months, with the average of (16 ± 3) months. No nerve or vascular injury, sacroiliac screw loosening or breakage had occurred. Conclusion For sacral longitudinal fracture, determination of safe pathway of screw insertion for S1 percutaneous transverse iliosacral screw fixation by intraoperative CT sagittal image projection on sacrum may provide surgical safety and simplified operation process.
Keywords：SacrumSacroiliac jointImage processingcomputer-assistedModelsanatomicImagingthree-dimensionalBone screwsFracture fixationinternalSurgery
Publication Date：2016-01-01
Pages：6( 69-74 )