Biomechanical effect of the iliac screw insertion depth on lumbo-iliac fixation construct

• Published in: Chung-hua wai kʿo tsa chih Vol. 46; no. 15; p. 1179
• Main Authors: Chen, Hui, Yu, Bin-sheng, Zheng, Zhao-min, Lü, You, Zhang, Kui-bo, Liu, Hui, Li, Fo-bao
• Format: Journal Article
• Language: Chinese
• Published: China 01.08.2008
• Subjects: Adult; Aged; Biomechanical Phenomena; Bone Screws; Female; Humans; Ilium - surgery; Lumbar Vertebrae - surgery; Male; Middle Aged; Pelvic Bones - surgery; Sacrum - surgery; Spinal Fusion - methods
• ISSN: 0529-5815

To biomechanically compare the stability of the short and long iliac screw fixation constructs in lumbo-iliac reconstruction. Seven adult human embalmed cadavers (L(3)-pelvis) were used. Using posterior spinal fixation system, L(4)-S(1) pedicle screw fixation was performed. This was defined as intact state of the sacroiliac joint. After the intact test, total sacrum resection and L(4)-L(5)-pelvis reconstruction by pedicle screw and iliac screw with different lengths were performed as follow: short screw group (as the length of exceeding 2 mm over ischial notch) and long screw group (as the length of exceeding 2 mm over anterior inferior iliac spine). Using the 858 MTS material testing machine, biomechanical testing was performed under 800 N compression and 7 Nm torsion loading modes. At last, the axial pullout test of two iliac screws was executed. Construct stiffness in compression and torsion test, and maximum pullout force were analyzed. Insertion lengths of the short and long iliac screw were (70 +/- 2) m