Fluoroscopic computer-assisted pedicle screw placement through a mature fusion mass: an assessment of 24 consecutive cases with independent analysis of computed tomography and clinical data.
METHODS
Observational matched cohort study with computed tomography (CT) analysis of pedicle screw placement.


OBJECTIVE
Assess the clinical accuracy of computer-assisted fluoroscopy for the placement of thoracolumbar pedicle screws through a mature posterolateral fusion mass.


BACKGROUND
Pedicle screw placement through an amorphous posterolateral fusion mass intuitively carries a higher risk of pedicle wall violation.


METHODS
Postoperative CT scans of 102 pedicle screws placed through a mature posterolateral fusion mass (n = 10 [T10-T12]; n = 92 [L1-S1]) were independently assessed and compared with a matched control (nonobscured anatomy) group. All screws were placed before any decompression using the FluoroNav system.


RESULTS
In the fusion mass group, overall 81.4% of screws were completely within the pedicle. Seven medial and 12 lateral pedicle breaches occurred. Relative to the total number of screws, pedicle breaches were graded II (<2 mm) in 13.5%, III (2-4 mm) in 2.9%, and IV (>4 mm) in 2.0% of screws. The number and direction of pedicle breaches were not significantly different when compared with the control group. There were no clinically significant screw misplacements in either group.


CONCLUSIONS
The use of computer-assisted fluoroscopy is safe and effective for the placement of thoracolumbar (T10-S1) pedicle screws through a posterolateral fusion mass without performing laminoforaminotomies.
Rampersaud
Yoga Raja
YR
Division of Orthopaedic, University of Toronto, Toronto, Ontario, Canada. raja.rampersaud@uhn.on.ca
Lee
Kwang-Soo
KS
D000328:Adult; D000368:Aged; D001863:Bone Screws / Q000009:adverse effects; D015331:Cohort Studies; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012086:Reoperation; D013123:Spinal Fusion; D025321:Surgery, Computer-Assisted; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome