gms | German Medical Science

Objective: The surgical treatment of upper cervical instability has recently undergone significant developments and changes. Numerous conditions (fractures, tumors, inflammatory processes) affect the craniocervical junction requiring treatment with fusion using polyaxial screws and rod fixation. Because of potentially hazardous complications including vertebral artery and spinal cord injury during C-1 lateral mass, C-2 and C-3 pedicle screw fixation the three-dimentional image-guided navigation is gaining popularity.

Method: Three dimensional (3D) image-guided navigation was used in 18 patients during the upper cervical fusion surgery in semisitting position in our clinic during 15 month (2012-2013).(Figure 1,2,3,4) During our post-operative radiological evaluation with multi-slice CT Scan we have divided pedicle screws position into 4 subgroups (Gertzbein classification): G 1a: central screws, G1b: not central but without pedicle perforation, G2: pedicle perforation <2mm and G3 pedicle perforation 2-4mm. Then we analyzed the frequency of different screws malposition and also the relation of pedicle screws malposition with other factors such as age of the patients and pathology and postoperative clinical findings.

Results: There were no new post-operative neurological and vascular complications related to image-guided navigated placement of 70 screws in our 18 cases. About 91% of pedicle screws come under subgroup G1 (G1a & b) and about 9% of pedicles screws come under G2 and G3 (Radiological malposition).

Conclusions: We found that three-dimentional image-guided navigation can serve as a useful adjunct during placement of upper cervical spine screws but the accuracy is not 100%. The clinical importance of radiological screws malposition and the effect of them in quality of life are doubtful.