ABSTRACT
@#Introduction: C1 lateral mass and C2 pedicular screws insertion are used for C1-C2 posterior fusion. Fluoroscopy Guided technique is routinely used for screw placement but it is associated with risk of injury to spinal cord and vertebral artery. 3D printing has developed rapidly in the fields of medicine. It is helpful in improving precise treatment and used for instrumentation in spine. We want to evaluate the accuracy of C1 lateral mass screws and C2 pedicle screws insertion by Pre-Fabricated Template made by threedimensional (3D) printing. Materials and methods: Five cervical samples were obtained from cadavers. Based on fine-cut CT scan 3Dimages reconstructed and the path of the screws designed by special software. A template produced by 3D-printer from 3D images. After printing the templates, they were fixed on the relevant vertebra in the operation room and based on the template path, C1 lateral mass screw and C2 pedicular screws were inserted. Placement of the screws was evaluated using CT scans post-operatively. Results: A total of 14 screws were inserted by abovementioned method. After evaluation with CT scans none of the screws were entered in the spinal canal. Two screws had vertebral artery canal perforation with less than 50% breach. Violation was judged as noncritical and would probably not have resulted in injury to vertebral artery. Conclusions: The accuracy of C1 lateral mass screw and C2 pedicle screw insertion is acceptable with pre-fabricated template and can provide a useful aid for screw placement.
ABSTRACT
Objective To explore the clinical effects of atlantoaxial pedicle screw instrumentation in treatment of intractable atlantoaxial dislocation in children. Methods A total of 7 patients with intractable atlantoaxial dislocations were treated with aflantoaxial pedicle screw instrumentation plus atlantoaxial bone grafting from June 2002 to January 2001. Results The dislocation in all patients reached complete reduction, with no complications. All patients were followed up for average 10 months (8-14 months). Radiographs showed successful bone fusion in all patients. Conclusion Atlantoaxial pedicle screw fixation and fusion is an effective method for treatment of intractable atlantoaxial dislocation in chil dren.
ABSTRACT
32 patients with old atlantoaxial dislocation with bulb-spinal cord compression were treated surgically from 1971 to 1989. Their diagnoses were confimed mainly by X-ray examination and measurement. The average time of follow-up after operation was 6 years. The rate fo excellence and good was 87.5% per cent. The causes of atlantoaxial dislocation, operative techniques involved and results are discussed. The authors think that the key to the increase of the therapeutic effects is early diagnosis and surgical treatment before the irreverisible changes of bulb-spinal cord compression occur.