Radiographic study of iliac screw passages

Abstract

BackgroundThe optimal iliac screw path was determined to provide references for lumbosacral-pelvic reconstruction.MethodsRadiographic data of 100 patients with normal pelvis were selected for this study. Four paths were designed. Paths A, B, and C were from the starting point of the crossing point of the chiotic line and posterior iliac crest (CLIC, located at 24.0 mm above the posterior superior iliac spine) to the upper edge of the acetabulum, anterior inferior iliac spine, and acetabulum center, respectively. Path D was from the starting point of the posterior superior iliac spine to the anterior inferior iliac spine. The lengths of the different paths of screw passage and bone plate thicknesses of two narrow places were measured and analyzed.ResultsPaths A, B, and D were approximately equal in length, but the thickness of the iliac plate in path A was significantly thicker than those in paths B and D. No significant difference was found between the iliac thickness of paths A and C, but the passage length of path A was significantly longer than that of path C.ConclusionPath A had the longest passage length and thickest iliac plate and could accommodate the relatively longest and thickest iliac screw. Thus, path A was the optimal iliac screw passage.

Comparative tomographic study of the S2-alar-iliac screw versus the iliac screw

“…Despite the concordance among some of the data published in this work with the literature, some numerical differences exist. Such variations in measured values can be explained by the choice of different entry points described in the studies, since even millimeter differences can alter the final measured result [3]. Deviations in lumbopelvic patterns according to race, ethnicity, sex, skeletal maturity and age may explain the differences in the measurements and may lead to changes in the angulation of the insertion of the screws and in their trajectories [15][16][17][18].…”

“…Spinopelvic rigid fixation is often necessary for the treatment of complex spinal pathologies [1]. The options described in the literature refer to the Galveston technique, developed by Allen BL, Jr., and Ferguson RL, which involves the longitudinal insertion of a bar between the two cortices of the iliac bone, or to more modern techniques, such as the use of the iliac screw (IS) and the S2-alar-iliac screw (S2AI) [2][3][4].…”

“…However, studies on the ideal technical positioning of both techniques are limited [10][11][12]. In addition, no reports have categorically determined the best positioning of the implant or performed a comparison between these techniques [1][2][3].…”

Sacropelvic Fixation Using Iliac Screws: Evaluation of Technique and Complications

“…2 Dissection up to the ischiatic notch is performed to prevent its perforation. The point of entry can vary according to some authors: situated about 2.4 cm above the AIIS to establish the best anchor point for the screw 22 or below the AIIS when the goal is to place more than one screw in the ilium. 23 In his anatomical and radiological study, Schildhauer 24 found an average PSIS-AIIS trajectory length of 141 mm in men and 129 mm in women and a possible accommodation of implants of 8 mm in diameter in men and 6-7 mm in women.…”

“…It was proven that the great disadvantage in the approach towards the acetabular roof was the risk of impingement. 25 To avoid increases in surgical time and bleeding several free-hand or scope-guided techniques emerged. 26 Fridley 27 developed a safe approach for the insertion of iliac screws using the superior edge of the lamina and the spinous process of L5 as anatomical parameters.…”