RT Journal Article
SR Electronic
T1 Comparison of Preoperative Pedicle Screw Measurement Between Computed Tomography and Magnet Resonance Imaging
JF International Journal of Spine Surgery
JO Int J Spine Surg
FD International Society for the Advancement of Spine Surgery
SP 7098
DO 10.14444/7098
A1 Pacha, Tarek Omar
A1 Omar, Mohamed
A1 Graulich, Tilmann
A1 Suero, Eduardo
A1 Mathis Schröder, Bennet
A1 Krettek, Christian
A1 Stubig, Timo
YR 2020
UL https://www.ijssurgery.com/content/early/2020/10/21/7098.abstract
AB Background Pedicle screw fixation is commonly used in the treatment of spinal pathologies. While the biomechanical factors that affect bone fixation have been frequently described, questions remain as to which imaging modality is the ideal medium for preoperative planning. Due to its perceived superiority in assessing bony changes, computed tomography (CT) scan is assumed to be the gold standard for preparative planning, and we hypothesize that magnetic resonance imaging (MRI) is sufficiently accurate to predict screw length and diameter compared to CT.Methods We retrospectively measured the length and diameter of vertebral bodies in the lumbar region in both MRI and CT and tested for differences between the modalities as well as for confounding effects of age, sex, and the presence of spondyloarthrosis.Results We found a significant difference in pedicle screw length between CT and MRI measurements for both sides. For the left pedicle, the mean difference was 1.89 mm (95% confidence interval [CI] −3.03 to −0.75; P < .002), while for the right pedicle, the mean difference was 2.05 mm (95% CI −3.27 to −0.84; P = .001). We also found a significant difference in diameter measurements between CT and MRI for the left pedicle (0.53 mm; 95% CI 0.13 to 0.93; P = .011) but not for the right pedicle (0.36 mm; 95% CI −0.06 to 0.78; P = .094). We identified no significant effect of sex, age or spondyloarthrosis on the results (P > .05).Conclusions Pedicle screw planning measurements were more accurate using CT images compared to MRI images. CT scan remains the gold standard for pedicle screw planning in trauma surgery. When using MRI images, the surgeon should be aware of the differences in screw length and diameter compared to CT in order to avoid intra- and postoperative risks.