A self-designed three-dimensional guiding instrument for percutaneous thoracolumbar pedicle screw implantation

Abstract

Objective To evaluate the clinical eeficacy of the self-designed three-dimensional guiding instrument used in the implantation of percutaneous thoracolumbar pedicle screws. Methods This study enrolled 52 patients who had undergone internal fixation with percutaneous thoracolumbar pedicle screws from January 2014 to March 2015 at our department. They were divided two groups, the instrument group and the manual group. There were 18 males and 7 females in the instrument group, with an average age of 56.1 ± 12.7 years (range, from 27 to 74 years) . Of them, 12 suffered from lumbar disc herniation , 4 from lumbar instability, and 9 thoracolumbar fracture. There were 17 males and 10 females in the manual group, with an average age of 57.3 ± 13.5 years (range, from 32 to 78 years). Of them, 14 suffered from lumbar disc herniation,5 from lumbar instability, and 8 from thoracolumbar fracture. There were no significant differences in general clinical data between the 2 groups preoperation (P > 0.05) . The positioning time, intraoperative fluoroscopy frequency, transverse screw angle (TSA), and sagittal screw angle (SSA) were compared between the 2 groups. Results All the operations were performed uneventfully. The positioning time (7.4 ± 3.2 min) and intraoperative fluoroscopy frequency (3.4 ± 1.9 times) in the instrument group were significantly less than in the manual group (12.3 ±4.4 min and 6.4 ±2.2 times, respectively) (P < 0.05). The interior and exterior pedicle walls were each pierced in one case, and the excessive cephalad or caudal deviation occurred in 2 cases in the instrument group; the interior pedicle wall was pierced in 4 cases, the exterior wall was pierced in 3 cases and the excessive cephalad or caudal deviation occurred in 3 cases in the manual group. The deviation rates of TSA and SSA in the instrument group (6.5%±2.6% and 9.6% ±3.8%, respectively) were significantly lower than in the manual group(18.6% ±5.8% and 16.0% ±3.8%,respectively) (P <0.05) . Conclusion Since our self-designed three-dimensional guiding instrument can effectively reduce radiation exposure and operation time, and increase success rate of positioning without increasing operative compilations, it is a great aid in the internal fixation with percutaneous thoracolumbar pedicle screws. Key words: Spinal fractures; Fracture fixation, internal; Bone nails; Guiding instrument