Radiographic comparison of cross-sectional lumbar pedicle fill when placing screws with navigation versus free-hand technique.
BACKGROUND
Pedicle screws are often used for spinal fixation. Increasing the percentage of pedicle that is filled with the screw presumably yields greater fixation. It has not been shown whether spinal navigation helps surgeons more completely fill their instrumented pedicles.


METHODS
Fifty consecutive patients from each arm (navigated and free-hand) were retrospectively reviewed. The cross-sectional area of each instrumented lumbar pedicle and screw were measured using an automatic area calculation tool. The coronal images and measurements were blinded to the surgeons.


RESULTS
The instrumented pedicles in the navigated patients were significantly more filled by screws than the pedicles in the non-navigated patients (P < 0.001).


CONCLUSIONS
Obtaining a higher cross-sectional percentage fill of the pedicle with a screw is expected to provide greater spinal fixation in instrumented fusion surgery. This study shows that utilizing spinal navigation helps to more completely fill the pedicles that are being instrumented. Copyright © 2015 John Wiley & Sons, Ltd.
Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida.
Stephen M
SM
Pirris
Department of Neuroscience, Mayo Clinic, Jacksonville, Florida.|St. Vincent's Brain and Spine Institute, Jacksonville, Florida.
Eric W
EW
Nottmeier
Mayo School of Health Sciences Mayo Clinic College of Medicine, Mayo Clinic, Jacksonville, Florida.|College of Science, University of Notre Dame, South Bend, Indiana.
Michael
M
O'Brien
Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida.
Gazanfar
G
Rahmathulla
Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida.
Mark
M
Pichelmann
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007432:Intraoperative Period; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D065289:Pedicle Screws; D011859:Radiography / Q000379:methods*; D012189:Retrospective Studies; D065287:Robotic Surgical Procedures; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*; D025321:Surgery, Computer-Assisted
image guidance; lumbar arthrodesis; pedicle cross-sectional area; pedicle screws; spinal fixation; spinal navigation