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Updated: Jun 27, 2026
A Spine Robotic-Assisted Navigation System for Pedicle Screw Placement
Published on: May 11, 2020
Real-Time navigation calibration for pedicle screw placement in neurofibromatosis Type 1-associated scoliosis: An
Guojun Li1, Rongjin Feng1, Huiqi Qian1
1Key Laboratory of Emergency and Trauma of Ministry of Education, Department of Spinal Surgery, The First Affiliated Hospital, Hainan Medical University, Haikou, China.
Objective:
To evaluate whether real-time intraoperative navigation calibration improves pedicle screw placement accuracy in patients with neurofibromatosis type 1-associated scoliosis.
Methods:
This retrospective study included 63 patients with NF1-associated scoliosis who underwent posterior spinal osteotomy, deformity correction, and instrumented fixation between January 2023 and June 2025. Patients were assigned to a conventional navigation group (n = 30) or a real-time navigation calibration group (n = 33). Pedicle morphology was classified according to Yang's classification, and screw placement accuracy was assessed on postoperative CT using the Rao grading system. Grade 0 indicated no cortical breach; Grades 1, 2, and 3 indicated breaches of < 2 mm, 2-4 mm, and > 4 mm, respectively.
Results:
A total of 430 pedicles were analyzed, including 230 in the conventional navigation group and 200 in the navigation calibration group. The distribution of pedicle morphology did not differ significantly between the groups. A total of 1,228 pedicle screws were inserted (584 in the conventional navigation group and 644 in the navigation calibration group). The navigation calibration group achieved significantly higher Grade 0 placement rates than the conventional navigation group in Type A, B, and C pedicles on the concave side and in Type A and B pedicles on the convex side. The overall cortical breach rate was also lower in the navigation calibration group. No significant between-group differences were observed in operative time, intraoperative blood loss, or perioperative complications.
Conclusion:
Real-time intraoperative navigation calibration improved pedicle screw placement accuracy and reduced cortical breaches in NF1-associated scoliosis, particularly in dysplastic pedicles and on the concave side of the deformity. This technique may serve as a practical adjunct to conventional optical navigation in complex spinal deformity surgery.
