A Study on Accuracy and Safety of Thoracic Pedicle Screw Fixation

Kim, Min Seok; Sung, Joo Kyoung

Abstract

OBJECTIVE
The purpose of this study is to evaluate the accuracy and safety of pedicle screws in the treatment of thoracic spine disease.
METHODS
Thirty-eight patients who had undergone thoracic pedicle screw fixation between January 2003 and December 2007 were retrospectively studied. Postoperative computed tomography scans were obtained using 3-mm axial cuts to evaluate the pedicle screw placement. The screws were further evaluated by the location and degree of the perforation.
RESULTS
Of the 214 thoracic pedicle screws placed, 174 (81.3%) were fully contained within the pedicle or anterior cortices of the vertebral body. Of the remaining 40 (18.7%) screws, 25 (62.5%) were lateral perforations, 12 (30.0%) were medial perforations, and 3 (7.5%) were anterior perforations of the vertebral body. The screws inserted at T1-T4 (28.5%) and T5-T8 (34.8%) revealed a higher perforation rate than the screws inserted at T9-12 (11.4%). No neurologic or vascular complications were encountered, but one screw 6 mm above a medial perforation required reinsertion.
CONCLUSION
Although clinical outcomes were not affected by mild displacement of thoracic pedicle screws, accurate measurements and considerable experience were required in the placement of screws, especially screws placed in the upper and midthoracic spine.