Influence of the two-dimension computer-aided navigation system to the concordance of lumbar spine pedicle screw fixation on both sides

Abstract

Objective To investigate the influence of the two-dimension computer-aided surgery navigation system to the concordance of lumbar spine pedicle screw fixation on both sides.Methods 1355 patients were undergone lumbar spinal pedicle screw fixation during January 2004 to December 2009.All patients were divided into tow groups:the navigation group (743cases) and the fluoroscopy assistant group (612 cases).All patients got standard A-P and lateral X-ray plate of lumbar spine within seven days after surgery.The X-ray images were analyzed by the software of Image-pro plus 5.0 to evaluate the concordance of lumbar spine pedicle screw fixation on both sides.The angle between axial line of pedicle screw and superior lamina terminals (α angle) and the angle between axial lines of pedicle screw on both sides (γangle) were measured.The position of the pedicle screw was checked weather it was in the lumbar pedicle partially.Results There were no significant differences (P＞0.05) between the α angle on both sides of L1-S5 vertebral body in navigation assistant group (L:3.89°±0.47°,R:3.94°±0.37°).The differences of the α angle on both sides of L2 (L:4.55°±1.27°,R:5.12°±1.87°) and L4 (L:4.22°±1.89°,R:6.62°±1.97°) vertebral body in the fluoroscopy assistant group had statistical significance (P＜0.05).There were no significant differences between the α angle on both sides of other bodies (L:4.32°±1.47°,R:4.37°±1.59°,P＞0.05).The γangle in navigation assistant group (2.32°± 0.27°) was obviously smaller than fluoroscopy assistant group (3.32°±1.51°),the differences had statistical significance (P＜0.05).Accuracy of pedicle screw in navigation assistant group was 91.5％ (3604/3938).Accuracy of pedicle screw in fluoroscopy assistant group was 87.6％ (2426/2768).The difference in accuracy of pedicle screw in both groups had statistical significance (x2=26.913,P＜0.0001).Conclusion The accuracy of pedicle screw and the concordance of pedicle screw on both sides can be significantly improved using the two-dimension perspective computer-aided surgery navigation system. Key words: Lumbar vertebrae; Surgery, computer-assisted; Internal fixators