Accuracy of Percutaneous Pedicle Screw Placement in Thoracolumbar Spines: A Comparison Study Between Experienced Spine Surgeons and Residents

Abstract

Purpose: The aim of this study was to investigate the difference in the accuracy of percutaneous pedicle screws (PPSs) insertion between spine surgery specialists and residents in cases of thoracolumbar surgery. Methods: We evaluated the insertion accuracy of 355 PPSs (left 178, right 177) used in 38 patients with thoracolumbar diseases surgically treated in our hospital between April 2009 and March 2016. A spine surgery specialist served as the main operator in 20 cases and a resident served as the main operator in 18 cases with a spine surgery specialist as the assistant. Using CT horizontal section images obtained within 2 weeks after surgery, the site of PPS insertion was evaluated according to four grades (Excellent, Good, Fair, Poor) in terms of six locations (Ia, Ib, IIa, IIb, IIIa, IIIb), mechanical fixation, and risk of occurrence of complications. Results: Among all 355 PPSs, Ia (Excellent) was achieved in 343 (96.6%). Twelve PPS insertions were classified as other grades, showing a deviation rate of 3.4%. All 12 of these insertions were rated as Ib (Good), and no other grades were identified. Spine surgery specialists performed 3 PPS insertions rated as Ib (Good), whereas residents performed 9 insertions rated as Ib (Good). There was no statistically significant difference between specialists and residents (P=0.083). All 12 insertions rated as other than Ia (Excellent) were insertions on the right side, but there was no consistent trend in terms of patient age or gender, disease, presence/absence of osteoporosis, spinal level, PPS model, or the location of the fluoroscopic system. Conclusion: PPS fixation is a safe procedure that allows for very accurate screw insertion by operators with limited clinical experience.