Computer-assisted navigation technique in the spinal pedicle screw internal fixation

Shugang LI; Lin SHENG; Hong ZHAO; Jianguo ZHANG; Jijiang ZHAI; Yong ZHU

ABSTRACT

BACKGROUND:

Recently, trans-pedicle screw internal fixation has markedly improved the rigidity of spinal fixation and hence the fusion rate. But when placed incorrectly, the pedicle screw can injure the spinal cord and/or nerve roots, resulting in serious complications.

OBJECTIVE:

To evaluate the application value of preoperative CT scans-based navigation technique in the spinal pedicle screw internal fixation surgery.DESIGN, TINE AND

SETTING:

A prospective, randomized, and controlled observation was performed at the Department of Orthopedics, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences between January 2006 and December 2008.

PARTICIPANTS:

A total of 95 patients who underwent pedicle screw internal fixation due to spine diseases were randomly assigned to a navigation group (n = 45) and a conventional group (n = 50).

METHODS:

In the navigation group, patients were subjected to pedicle screw insertion with the assistance of computer navigation technique and while in the conventional group, patients underwent pedicle screw insertion using the conventional anatomic landmark combined with fluoroscopy.MAIN OUTCOME

MEASURES:

Screw channel preparation time, excellent and good rate of screw position, and postoperative complications.

RESULTS:

In the navigation group, totally 206 pedicle screws were inserted under navigation guidance, with an excellent and good rate of 96.1%; and navigation could not be continued in 9 patients for a three-dimensional registration error. In the conventional group, altogether 285 pedicle screws were inserted, and the excellent and good rate was 100%. No significant difference was found between the two groups (P > 0.05). The navigation group exhibited longer screw channel preparation time than the conventional group [(360±22) seconds vs. (56+8) seconds, P < 0.01]. No postoperative complications were found in each group.

CONCLUSION:

The preoperative CT scans-based navigation technique produces similar accuracy of pedicle screw insertion, but markedly prolonged operation time, compared with the conventional anatomic landmarks, exhibiting limited application value in the spinal pedicle screw internal fixation.