In vitro simulation. Early results of stereotaxy for pedicle screw placement.
METHODS
Frameless stereotaxy with doppler ultrasound and three dimensional computer model registration is assessed in vitro for pedicle screw placement.


OBJECTIVE
To identify feasibility of pedicle screw navigation and placement using this technology.


BACKGROUND
Inaccurate pedicle screw placement can lead to neurovascular injury or suboptimal fixation. Present techniques in pedicle screw placement involve only confirmation of hole orientation.


METHODS
Forty-four pedicle screws were placed in lumbosacral models and cadaver specimens. Accuracy was assessed with a computed tomography scan and vertebral cross sectioning.


RESULTS
All screws were intrapedicular. Accuracy of anterior cortical fixation was 1.5 mm, with a range of 2.5 mm.


CONCLUSIONS
In vitro frameless stereotaxy is accurate for pedicle screw placement. This technology adds a component of navigation to pedicle screw placement.
Carl
A L
AL
Division of Orthopaedic Surgery, Albany Medical College, New York, USA.
Khanuja
H S
HS
Sachs
B L
BL
Gatto
C A
CA
vomLehn
J
J
Vosburgh
K
K
Schenck
J
J
Lorensen
W
W
Rohling
K
K
Disler
D
D
D001863:Bone Screws; D002102:Cadaver; D003198:Computer Simulation; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008159:Lumbar Vertebrae / Q000601:surgery*; D012447:Sacrum / Q000601:surgery*; D013238:Stereotaxic Techniques; D014057:Tomography, X-Ray Computed