Neurovascular Relations in Modified Iliac Screws and Traditional Iliac Screw: Anatomic Study.

Publication Title

World Neurosurg

Authors

Alexander von Glinski, Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USA; Hansjörg Wyss Hip and Pelvic Center, Swedish Hospital, Seattle, Washington, USA
Emre Yilmaz
Basem Ishak, Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USA
Wyatt L Ramey, Department of Neurosurgery, Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USAFollow
Andrew Jack, Department of Neurosurgery, Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USAFollow
Joe Iwanaga
Amir Abdul-Jabbar, Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USAFollow
Rod J Oskouian, Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USAFollow
R Shane Tubbs, Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USA
Jens R Chapman, Swedish Neuroscience Institute, Swedish Medical Center, Seattle, Washington, USAFollow

Document Type

Article

Publication Date

2-1-2020

Keywords

Adult; Bone Screws; Cadaver; Female; Fluoroscopy; Humans; Ilium; Male; Risk; Sacrum; Spinal Fusion; Iliac screws; Lumbopelvic fixation; Modified insertion point; Neurovascular injuries; Supragluteal artery

Abstract

BACKGROUND: This study describes a modified iliac screw technique and compares it with the traditional iliac screw in regard to neurovascular structures at risk. Few studies have detailed the insertion point's surrounding anatomy and its relationship to vulnerable neurovascular structures when this modified technique is used. Therefore we describe our modified iliac screw entry and trajectory and detail the surrounding anatomy and neurovascular structures at risk with this technique in comparison with the "gold standard" trajectory.

METHODS: The traditional iliac screw (TS) and modified iliac screw (MS) were placed into 12 fresh-frozen adult cadavers (3 female, 9 male). We measured the screw-to-supragluteal artery, vein, and nerve (SGANV) bundle and screw-to-sciatic notch distances. Further, we dissected the medial cortical border of the iliac screw to identify its final position with respect to the surrounding anatomy.

RESULTS: No medial or lateral cortical breaches were visualized after screw placement. The MS was 18.31 mm from the greater sciatic foramen compared with 18.65 mm with the TS. The smallest distance from the MS to the greater sciatic foramen was 13.9 mm compared with 14.8 mm with the TS, an insignificant difference. The SGANV bundle-to-MS distance was 20.6 mm, and SGANV bundle-to-TS distance was 20.77 mm, again an insignificant difference.

CONCLUSIONS: Using the modified iliac screw technique does not change the intraosseous pathway (and thus bone purchase) with respect to the distance between the screw and neurovascular structures at risk.

Area of Special Interest

Neurosciences (Brain & Spine)

Specialty/Research Institute

Neurosciences