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Iliac Screw Fixation Using Computer-Assisted Computer Tomographic Image Guidance: Technical Note

Shin, John H. MD*; Hoh, Daniel J. MD; Kalfas, Iain H. MD§

doi: 10.1227/NEU.0b013e318230517a
Instrumentation and Technique

BACKGROUND: Iliac screw fixation is a powerful tool used by spine surgeons to achieve fusion across the lumbosacral junction for a number of indications, including deformity, tumor, and pseudarthrosis. Complications associated with screw placement are related to blind trajectory selection and excessive soft tissue dissection.

OBJECTIVE: To describe the technique of iliac screw fixation using computed tomographic (CT)-based image guidance.

METHODS: Intraoperative registration and verification of anatomic landmarks are performed with the use of a preoperatively acquired CT of the lumbosacral spine. With the navigation probe, the ideal starting point for screw placement is selected while visualizing the intended trajectory and target on a computer screen. Once the starting point is selected and marked with a burr, a drill guide is docked within this point and the navigation probe re-inserted, confirming the trajectory. The probe is then removed and the high-speed drill reinserted within the drill guide. Drilling is performed to a depth measured on the computer screen and a screw is placed.

RESULTS: Confirmation of accurate placement of iliac screws can be performed with standard radiographs.

CONCLUSION: CT-guided navigation allows for 3-dimensional visualization of the pelvis and minimizes complications associated with soft-tissue dissection and breach of the ilium during screw placement.

*Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts

Department of Neurosurgery, University of Florida, Gainesville, Florida

§Department of Neurosurgery, Center for Spine Health, Cleveland Clinic, Cleveland, Ohio

Correspondence: John H. Shin, MD, Department of Neurosurgery, Massachusetts General Hospital, 55 Fruit Street, WAC 745, Boston, MA 02114. E-mail:

Received September 20, 2010

Accepted June 6, 2011

Copyright © by the Congress of Neurological Surgeons