Computer-assisted fluoroscopic navigation of pedicle screw insertion: an in vivo feasibility study.

BACKGROUND Accurate placement of pedicle screws is difficult. PATIENTS AND METHODS We evaluated the feasibility and accuracy of pedicle screw insertion assisted by a real-time, 2-dimensional (2D) image-guided navigation system in 12 patients who underwent thoraco-lumbar and/or lumbar stabilization. 66 pedicle screws were inserted either by senior spine surgeons or residents. The accuracy of positioning of the screws was evaluated using postoperative plain radiographs and thin-cut CT. RESULTS 61 of the 66 screws were inserted successfully. 5 screw insertions showed structural violations: 4 on the medial and 1 on the lateral pedicle wall. The accuracy was higher in the sagittal plane than in the axial plain. There was no difference between the surgical error rates caused by the senior surgeons and the residents. INTERPRETATION Using computer-assisted 2D fluoroscopic image navigation, it is possible to achieve reliable and accurate pedicle screw insertion during low thoracic and lumbar spinal surgery.