Intraoperative fluoroscopy in percutaneous sacroiliac screw fixation based on anatomic measurement and digital reconstructed CT data
10.3760/cma.j.issn.1671-7600.2012.05.009
- VernacularTitle:基于CT图像解剖学测量和数字重建透视的经皮骶髂螺钉固定术中透视方法研究
- Author:
Yonggang SU
;
Maoying WANG
;
Manyi WANG
- Publication Type:Journal Article
- Keywords:
Bone nails;
Pelvis;
Tomography,X-ray computed;
Image processing,computer-assisted;
Sacroiliac joint
- From:
Chinese Journal of Orthopaedic Trauma
2012;14(5):405-409
- CountryChina
- Language:Chinese
-
Abstract:
Objective To explore the intraoperative fluoroscopy in percutaneous sacroiliac screw fixation based on anatomic measurement and digital reconstructed CT data. Methods The CT data of the pelvis at prostration were collected for 3D reconstruction of the pelvic models from 30 patients with injury to the pelvis or acetabulum.Then the anatomical boundaries of thesafe zone of sacroiliac screw insertion were marked on the 3D models,including the upper,front and back cortex boundaries of S1 vertebra,the front and bottom cortex boundaries of sacral foramen area,and the sacral alar slope. The angles between these anatomical boundaries and the pelvic baseline were measured on the sagittal plane.The digital reconstructed radiology (DRR) was applied to form the inlet,outlet and lateral images of fluoroscopy.The standard protocol to acquire accurate intraoperative images was analyzed by characterization of important anatomic landmarks.Results The angles between the upper,front and back cortex boundaries of S1 vertebra and the baseline (αl,α2,α3) were respectively 37.7°± 8.6°(from 23.2°to 50.8°),22.9° ± 6.7° (from 13.1° to 32.0°),41.9°± 6.8° (from 33.0°to 54.8°).The angles between the front and bottom cortex boundaries of sacral foramen area and the baseline (α4,α5) were 37.0°± 12.0° (from 19.9° to 63.1°) and 38.8°± 8.0° (from 25.7°to 54.6°).The angle between the alar slope and the baseline (α6) was 82.4°± 13.0°(from 70.3°to117.3°).The characteristic manifestations of important anatomic landmarks were observed in the simulated fluoroscopy images. Conclusions It is recommended that the projecting angles in the inlet and outlet views should be decided according to the specific data of each patient.Because the alar slope can not be clearly identified in the outlet view due to its large inclination,the position of screw insertion should be verified in the lateral view to prevent the screw from penetrating the slope to hurt the L5 nerve and iliac vessels.
