The use of computer-assisted navigation system for pedicle screw installation during thoracic spine surgery / 中华骨科杂志

ABSTRACT

Objective To explore the clinical application of computer-assisted three-dimensional navigation system for thoracic pedicle screw placement. Methods From May 2003 to May 2004, the computer-assisted three-dimensional navigation system was used for thoracic pedicle screw placement in 80 screws of 15 cases, including 30 in the upper thoracic spine and 50 in the middle or lower thoracic spine. These fifteen patients included ten male and five female with a mean age of 47 years (range 13-76 years). In this series of 15 patients, thoracic spinal surgery was performed for tumor resection and reconstruction in 5, burst fracture in 4, ossification of thoracic ligamentum flavum in 2 and thoracic scoliosis in 4. The pedicle screw position was assessed with "C"-arm fluoroscopy during operation and with CT post-operation. The cost of time for pedicle screw installation and amount of bleeding were recorded. Results The cost of time averaged 15 minutes (range 10-20 min) for each pedicle screw placement. The amount of bleeding varied, it averaged 1200 ml in thoracic tumor resection and reconstruction, 800 ml in posterior fixation for burst fracture, 300 ml in resection of ossified ligamentum flavum, and 500 ml in surgery for scoliosis. The pedicle screw position was graded post-operatively with CT scanning into three groups gradeⅠ, perfectly placed, grade Ⅱ, cortical perforation less or equal to 2 mm, and grade Ⅲ, perforation more than 2 mm. Of these 80 screws, 76 screws (96%) were found in gradeⅠ, 2 in gradeⅡ, and 2 in grade Ⅲ. All of the 4 screws in gradeⅡor Ⅲ were placed deviating to the lateral portion of pedicles, and no neurological deficit was resulted. Conclusion The computer-assisted three-dimensional navigation system is a valuable tool both for improving the accuracy of thoracic pedicle screw installation, and increasing the overall safety of the procedure during thoracic spine surgery.