Clinical testing of an alternate method of inserting bone-implanted fiducial markers.
BACKGROUND
Deep brain stimulation (DBS) surgery utilizes image guidance via bone-implanted fiducial markers to achieve the desired submillimetric accuracy and to provide means for attaching microstereotactic frames. For maximal benefit, the markers must be inserted to the correct depth since over-insertion leads to stripping and under-insertion leads to instability.


OBJECTIVE
The purpose of the study was to test clinically a depth-release drive system, the PosiSeat™, versus manual insertion (pilot hole followed by manual screwing until tactile determined correct seating) for implanting fiducial markers into the bone.


METHODS
With institutional review board approval, the PosiSeat™ was used to implant markers in 15 DBS patients (57 fiducials). On post-insertion CT scans, the depth of the gap between the shoulder of the fiducial markers and the closest bone surface was measured. Similar depth measurements were performed on the CT scans of 64 DBS patients (250 fiducials), who underwent manual fiducial insertion.


RESULTS
Median of shoulder-to-bone distance for PosiSeat™ and manual insertion group were 0.03 and 1.06 mm, respectively. Fifty percent of the fiducials had the shoulder-to-bone distances within 0.01-0.09 mm range for the PosiSeat group and 0.04-1.45 mm range for the manual insertion group. These differences were statistically significant.


CONCLUSIONS
A depth-release drive system achieves more consistent placement of bone-implanted fiducial markers than manual insertion.
Department of Otolaryngology, Vanderbilt University Medical Center, 1215 21st Avenue South, MCE 7209, South Tower, Nashville, TN , 37232, USA, ramya.balachandran@vanderbilt.edu.
Ramya
R
Balachandran
Mark A
MA
Fritz
Mary S
MS
Dietrich
Andrei
A
Danilchenko
Jason E
JE
Mitchell
Veronica L
VL
Oldfield
Wendy W
WW
Lipscomb
J Michael
JM
Fitzpatrick
Joseph S
JS
Neimat
Peter E
PE
Konrad
Robert F
RF
Labadie
D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000601:surgery; D003198:Computer Simulation; D057918:Fiducial Markers; D006801:Humans; D019919:Prosthesis Implantation / Q000379:methods*; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed / Q000379:methods*