Spine Bull’s-Eye Robot Guidewire Placement With Pedicle Standard Axis View for Thoracic and Lumbar Pedicle Screw Fixation

Abstract

STUDY DESIGN: Prospective. OBJECTIVE: To explore the feasibility and accuracy of thoracic and lumbar pedicle guidewire placement using a newly developed Spine Bull's-Eye Robot with the pedicle standard axis view (PSAV). SUMMARY OF BACKGROUND DATA: Placement of pedicle screws in the thoracic spine is considered to be particularly risky surgery and is associated with a relatively high rate of screw misplacement. Use of robot-assisted surgery may improve the accuracy of pedicle screw placement. METHODS: The study included 204 pedicles (T1-L5) from 6 human vertebrae and 5 pedicles from 3 patients. Computed tomographic reconstruction of target vertebrae was performed for surgical planning. Using the PSAV, a guidewire (1.2 mm diameter, 13.5 cm length) was inserted into the "bull's-eye" (the center of the pedicle circular projection) using the remotely operated Spine Bull's-Eye Robot. After surgery, vertebral body axial and lateral radiographs, and computed tomographic scans were used to assess the guidewire trajectory. Planned and actual (postoperative) measures for transverse section angle, sagittal section angle, and the superior/inferior and medial/lateral vertical distances from the entry point were compared. RESULTS: The PSAV was acquired clearly in 203 of 209 (97.1%) pedicles; the guidewire was successfully inserted in each of these pedicles. There were no significant differences between any of the planned and actual (postoperative) measures. All of the pedicles for which guidewire placement was abandoned (because of lack of bull's-eye resolution in the PSAV) were small upper thoracic specimens, exhibiting evidence of decalcification, presumably because of preservation procedures. None of the patients experienced complications associated with guidewire placement. CONCLUSIONS: Use of the Spine Bull's-Eye Robot with PSAV seems be an accurate and feasible approach for guidewire (and thus pedicle screw) placement in the thoracic and lumbar spine.