关键词: 解剖标志, 胸椎椎弓根螺钉, 徒手置钉

Abstract:

Objective 　 To evaluate the accuracy and safety of freehand placing thoracic pedicle screw technique with uniform anatomical marks, as compared with the conventional freehand technique． Methods　From December 2014 to February 2015, a contrast study was performed on 25 patients needed posterior surgery with pedicle screw in our department. The right side thoracic pedicle screws were implanted with uniform anatomical marks put forwarded by Fennell, while the left side ones were done with traditional method described by Kim. The accuracy and safety of the pedicle screw placements was evaluated according to Heary classification after operation. And the time of implanting screws on each side was compared.  Results   A total of 133 thoracic pedicle screws were assessed. There were 67 screws implanted by the new method. The accuracy of this technology was 89.55% (Heary classⅠ) and the security was 97.01% (Heary classⅡabove). 7 (10.45%) screws were considered in a negative location (below Heary classⅠ).The average time of placing pedicle each screw was 5.75 min. while, there were 66 pedicle screws implanted by traditional method. The accuracy of this technology was 75.76% and the security was 89.39%. A total of 16 screws (24.24%) developed bad location. The average time of placing each pedicle screw was 8.95 min. A significant difference in the accuracy of pedicle screw placement was observed between the 2 methods（P＜0.05）,But on the security of implanting screws has no statistically significant (P > 0.1). In addition, there was significant difference in the implanting time between the 2 methods (P< 0.05).　Conclusion　Free hand placing thoracic pedicle screw technique with uniform anatomical marks is more accurate for screw location, more simple for operation, more easy for acceptance, learning and communication.

Key words: Anatomical marks, Thoracic pedicle screw, Freehand placing screw