TRANSPEDICULAR SCREW PLACEMENT ACCURACY USING THE O-ARM VERSUS FLUOROSCOPY-ASSISTED FREEHAND TECHNIQUE IN THORACOLUMBAR SPINE SCOLIOSIS SURGERY: A COMPARATIVE STUDY

Abstract

Objective: to compare the accuracy and safety of screw placement using O-arm navigation versus fluoroscopy-assisted freehand methods in a tertiary spine center setting.

Study design: Comparative cross-sectional

Place and duration of study: Study was conducted at the Department of Spine Surgery, CMH Rawalpindi, Pakistan, from November 2024 to June 2025.

Methodology: Seventy-six patients undergoing posterior spinal fusion for scoliosis were included and divided into two groups: Group A (O-arm navigation, n = 30) and Group B (fluoroscopy-assisted freehand, n = 46). Pedicle screws were inserted from T10 to L4, and placement accuracy was evaluated postoperatively using the Gertzbein-Robbins classification. Grades A and B were considered acceptable. Independent radiologists, blinded to the surgical technique, assessed CT scans. Data were analyzed using SPSS v26.0.

Results: A total of 984 screws were analyzed, 376 in the O-arm group and 608 in the freehand group. The O-arm group demonstrated significantly higher Grade A placements (83.8% vs. 62.8%, p < 0.001) and overall acceptable accuracy (95.7% vs. 86.0%, p < 0.01). Breach rates, particularly medial breaches were notably lower in the O-arm group (1.9% vs. 6.7%, p < 0.01). Although operative time was longer with O-arm navigation, it was associated with less blood loss and fewer postoperative complications.

Conclusion: O-arm navigation significantly improves the accuracy and safety of pedicle screw placement in thoracolumbar scoliosis surgery offering a valuable advantage over conventional fluoroscopy-assisted techniques