Application of posterior atlantoaxial pedicle screw-rod internal fixation in young children with upper cervical disorders

English Keywords:Yound children(1-5 years old)  Upper cervical disorders  Craniocervical junction deformity  Atlantoaxial dislocation  Basilar invagination  Pedicle screw rod internal fixation

English Abstract:

  【Abstract】 Objectives: To investigate the application effect of posterior atlantoaxial pedicle screw-rod internal fixation in 1-5 year old children with upper cervical disorders. Methods: 13 children with upper cervical disorders treated by our team with atlantoaxial pedicle screw-rod internal fixation were studied retrospectively, which consisted of 10 boys and 3 girls, aged 43.85±17.56 months(15-68 months) old, and weighted 16.32±3.23kg(9-22.5kg). The main clinical manifestation of the children with upper cervical disorders combined with atlantoaxial dislocation was neck pain and limitation of neck motion, besides, limb weakness occurred in 2 patients and neck deviation as the main manifestation occurred 1 patient; 2 patients were of American Spinal Injury Association(ASIA) grade C, 1 patient was of grade D, and 10 were of grade E before operation. Frontal and lateral open mouth and dynamic X-ray, CT bone three-dimensional reconstruction, vertebral artery CT angiography(CTA), MRI plain or enhanced examination were performed before operation. All the 13 children patients underwent posterior atlantoaxial vertebral reduction and pedicle screw-rod internal fixation(3.5mm in diameter for pedicle screw) since the dislocation could be completely or mostly reduced after routine bedside occipital jaw band or skull traction and skull traction under anesthesia. Except for 4 cases of fresh type Ⅱ odontoid fracture with atlantoaxial dislocation, the other patients were treated with autologous iliac bone graft fusion. Occipito-cervical fixation and fusion were performed on the 3 patients who were unable to undergo atlantoaxial pedicle screw-rod fixation due to craniocervical junction deformity or atlantoaxial dysplasia. Results: All the operations went smoothly without dura, spinal cord, vertebral artery or nerve root injury. A total of 50 posterior cervical screws and 3 occipital plates were implanted, including 41 atlantoaxial pedicle screws, 3 axial lamina screws, and 6 C3 and C4 lateral mass screws. The operative time was 136.92±30.38min(100-180min), and intraoperative blood loss was 73.33±35.43ml(30-150ml) without blood transfusion. The length of hospital stay was 15.58±8.37 days(5-31 days). All the patients were followed up 47.46±36.26 months(3-109 months). After the operation, the atlantoaxial distance was decreased and the minimum sagittal diameter of spinal canal was increased significantly compared with the preoperative ones respectively(1.19±0.19cm vs 1.81±0.34cm, 1.42±0.30cm vs 1.08±0.43cm, P<0.05). None complained of neck pain or limitation of neck motion at 3-month follow-up after surgery; and except for the patients recieved occipital-cervical fixation and fusion, the rest patients only complained of slight neck rotation limitation. There was significant difference in JOA score between follow-up and preoperation(17.00±0.00 vs 16.23±0.48, P>0.05). 1 patient of ASIA grade C and 2 patients of grade D improved to grade E at the final follow-up. The period for bony fusion of all the patients received autogenous iliac bone graft fusion was 4.15±1.60 months(2.5-6 months). The 4 patients received simple atlantoaxial pedicle screw fixation returned to the hospital for removal of internal fixation after odontoid fracture healed, and no atlantoaxial instability was found and normal function was restored during follow-up. Conclusions: The 3.5mm diameter pedicle screw can be applied safely and effectively on most of the yound children(≥1 year and 3 months old) with upper cervical disorders, and the long-term efficacy is satisfactory. For some children with atlantoaxial dysplasia or craniocervical junction deformity, atlantoaxial pedicle screw combined with axial laminar screw or occipital-cervical fixation and fusion serves an effective remedy.