Percutaneous insertion of sacroiliac joint screws under real-time 3D navigation

Abstract

Objective To study the feasibility of using real-time three-dimensional (3D) navigation based on preoperative CT scans in percutaneous insertion of sacroiliac joint screws.Methods CT scanning was performed in 5 cadaveric specimens of normal pelvis into which 5 titanium screws were inserted as markers along the iliac wings.The CT scan data were imported to the SuperImage software for 3D reconstruction of the pelvic models.The 3D models were transferred to the navigation software to determine safe approaches for placement of sacroiliac joint screws on the basis of coordinates of the titanium screw markers in the virtual 3D space.Coordinates of the titanium screws in real space were obtained by the navigation probe before they were matched to the markers in the 3D model to complete the registration.Next the system real-time tracked the positions of surgical instruments and the cadaveric pelvis.Under the real-time 3D navigation,percutaneous implantation of one sacroiliac joint screw was completed in each of the 5 pelvic specimens in accordance with the safe approaches planned preoperation.Operative time was record.CT scans of the pelvis were obtained postoperatively for 3D reconstruction.Positions of the screws in postoperative 3D models were observed and compared with those in the preoperative models.Results In each of the 5 cadaveric specimens of normal pelvis,one sacroiliac screw was successfully inserted along safe approach planned preoperatively.Postoperative CT scanning showed that the placement of 5 screws was highly accurate and consistent with the preoperative virtual planning.The operative time ranged from 19 to 23 minutes,averaging 21.6 minutes.Conclusions Since 3D real-time navigation can make a good use of preoperative virtual planning,screws can be placed accurately,simply and quickly in the operation without X-ray fluoroscopy.It is feasible to use 3D real-time navigation on the basis of preoperative CT scans in the percutaneous fixation with sacroiliac joint screws. Key words: Pelvis; Sacroiliac joint; Bone nails; Surgery, computer-assisted; Tomography,X-ray computed