Objectives: To study the accuracy and safety of pedicle screw insertion by three-dimensional frameless stereotactic-
guided technique.
Material and Method: Twelve patients underwent spinal surgery using three- dimensional frameless stereotactic-
guided technique at King Chulalongkorn Memorial Hospital (KCMH) during June - December 2004. In all patients, post-operative CT scan of the operated spinal segments were obtained and evaluated for the position of each screw placed. Medical records were reviewed and all patients were interviewed by telephone to assess clinical outcomes and complications
Results: 51 pedicle screws were inserted in 12 patients. Postoperative CT scan of the instrumented spine revealed that 50 screws were considered grade I screw while one screw was considered grade II. No patient suffered direct vascular or neurological injury.
Conclusion: Three-dimensional frameless stereotactic-guided technique provides additional safety to spinal instrumentation

Keywords: Spinal surgery, Spinal instrumentation, Sterotactic guided