3D printed pedicle screw guides reduce the rate of intraoperative screw revision in adolescent idiopathic scoliosis surgery.

ABSTRACT

BACKGROUND CONTEXT Pedicle screw fixation has become common in the treatment of adolescent idiopathic scoliosis (AIS). Malpositioned pedicle screws have significant complications and identifying surgical techniques to optimize screw placement accuracy is imperative. PURPOSE: To compare the rate of intraoperative revision, replacement, or removal of pedicle screws placed utilizing 3D printed guides compared with pedicle screws placed utilizing a freehand technique. STUDY DESIGN/SETTING: Retrospective cohort study/single academic center. PATIENT SAMPLE Thirty-two patients aged 10 to 18 with AIS. OUTCOME MEASURES: Revision rate of pedicle screws and operative time between groups. METHODS: A retrospective study was performed on patients 10 to 18 years of age who underwent posterior spinal instrumented fusion for AIS from February 2021 to July 2022. The study received an IRB exemption. Patient demographics, intraoperative measures, and outcome variables were recorded. Intraoperatively, all patients underwent a 3-dimensional fluoroscopic "check scan," which included axial, sagittal, and coronal images, to assess for screw accuracy. A secondary outcome of operative time was compared between groups. The p-values <.05 were considered significant. RESULTS: A total of 32 patients were included in this study. There were 17 cases in the 3D guided and 15 cases in fluoroscopy-guided freehand cohort. There was a total of 254 pedicle screws using 3D guides and 402 screws using freehand technique. Between cohorts, there were no significant differences in a number of levels fused (p=.54) or length of surgery (p=.36). The total revision rate of 3D guided screw placement was 5.5% and that of the freehand technique was 8.5%. The freehand screw placement group had significantly higher revision rates per vertebral level compared with 3D guided (p=.0096). Notably, 3D printed guides had fewer screws that were removed/revised for being too anterior (7.1%) compared with freehand (23.5%). Surgical time was not significantly different between the 3D guided and freehand cohort (p=.35). CONCLUSIONS: 3D printed guides reduce intraoperative revision rate compared with freehand techniques. Total operative time is comparable to freehand technique.