Analysis of accuracy of computer-assisted navigation in cervical pedicle screw installation.
OBJECTIVE
To observe the accuracy of computer-assisted navigation (CAN) in cervical pedicle screw installation and to analyze the reasons for screw malposition.


METHODS
From October 2004 to December 2009, 144 cervical pedicle screws were installed in 25 patients with cervical spinal diseases using CAN. Screw position and direction were measured on sagittal and transection images from intraoperative navigation and postoperative CTs.


RESULTS
Among 144 screws inserted from C3 to C7, two perforated the upper pedicle wall and three deviated from the lateral pedicle wall. The rate of accurate cervical pedicle screw placement with CAN was 96.5% (139/144) in our group. There was no statistical difference in the position and direction of the pedicle screws according to navigation images and CT scans.


CONCLUSIONS
CAN can result in high accuracy of cervical pedicle installation. The excursion phenomenon is responsible for malposition of pedicle screws. Only by understanding the navigational principles of CAN and the characteristics of cervical spinal surgery, together with personal experience, can good use be made of CAN.
Department of Orthopaedics, Liaocheng People's Hospital, Shandong, China. zhleidoctor@163.com
Hong-lei
HL
Zhang
Dong-sheng
DS
Zhou
Zhen-song
ZS
Jiang
D000328:Adult; D000368:Aged; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery*; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D008875:Middle Aged; D015641:Radiography, Interventional / Q000379:methods; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult