Atlanto-axial pedicle screw plate and fusion in treatment of upper cervical injuries / 中国矫形外科杂志

[Objective]To investigate the effect of atlanto-axial pedicle screw plate and fusion in treatment of upper cervical injuries. [Methods]Fifty-six cases of upper cervical spine injuries were treated with atlanto-axial pedicle screw plate and internal fixation,with total 200 screws,from March 2000 to September 2007.There were 36 males and 14 females,with an average age of 41.52 years(ranged,20~65 years).There were 23 cases of type II odontoid process fracture,12 cases of odontoid process nonunion,15 cases of transverse ligament injury.[Results]Greater occipital nerve pain occurred in 4 cases postoperatively and fully recovered after treatment 1 month later.The lateral cortical bone was penetrated by screws in 2 cases,without spinal cord or vertebral artery injury.Forty-eight cases were followed up for an average of 27.56 months(ranged,25~60 months).Bone fusion was achieved in all cases,without plate or screw broken.X-ray showed complete replacement of atlas and odontoid process of axis fracture.CT showed good position relation between screw and vertebral artery or spinal cord.According to JOA classification,excellent result was achieved in 34 cases,good in 13 cases,fair in 2 cases,poor in 1 case,with the good-to-excellent rate of 94.00%.[Conclusion]Atlanto-axial pedicle screw combined with plate fixation system is effective in treatment of upper cervical injuries.It can significantly improve the biomechanical stability of atlantoaxial joint,with high bone graft fusion rate.

Unilateral Fusion of the Odontoid Process with the Atlas in Klippel-Feil syndrome: A Case Report

Klippel-Feil syndrome (KFS) displays congenital fusion of the cervical vertebrae; it is a relatively common condition and has many associated malformations such as Sprengel's deformity, scoliosis, rib anomalies, congenital defects of the brain or spinal cord, renal anomalies, congenital heart disease, deafness, cleft palate, cranial and facial asymmetry, and enteric cysts. There are various types of cervical fusion observed in KFS. However, fusion of the odontoid process with the atlas is a very rare finding. We report here on a 4-year-old boy with unilateral fusion of a separated odontoid process with the lateral mass of the atlas, and this was associated with a spontaneously closed ventricular septal defect, a small patent ductus arteriosus and a horseshoe kidney.

Postnatal Development of the Atlas and Axis: CT Study

PURPOSE: To evaluate normal postnatal development of the atlas and axis by means of CT scanning. MATERIALS AND METHODS: We prospectively analyzed CT scans of the developing atlas and axis of 200 normal children aged less than 14, investigating the CT appearance of these regions with particular attention to two synchondroses related to the atlas and four synchondroses and one ossification center related to the axis. Fusion varying was categorized as either low (grade1-5) or high (grade4-5), according to the varying degrees of fusion at each synchondrosis or ossification center. RESULTS: Neurocentral synchondrosis of the atlas was low grade in all children less than five, and high grade in all aged nine or more, while posterior synchonrosis of the atlas was low grade in 97% of children less than three and high grade in 99% aged three or more. As for the axis, neurocentral synchondrosis was low grade in all children less than three, and high grade in 97% of children aged five or more. PS of the axis was low grade in both children less than 6 months, and high grade in all aged two years or more. Dentocentral synchondrosis of the axis was low grade in 93% of children less than three and high grade in 96% of those aged at least five. Intradental axial synchondrosis was high grade in all children. Fusion of the terminal ossicle with the remainder of the dens was low in all children less than five and high in 97% of those aged nine or more. CONCLUSION: CT can help determine the parameters of normal postnatal development of the atlas and axis. A knowledge of normal ossification patterns of these regions may help provide an understanding of developmental anomalies and also help prevent confusion with fractures.

Application of Spiral CT in Atlantoaxial Lesion / 实用放射学杂志

Objective To evaluate the diagnostic value of three-dimensional CT(3DCT)in atlantoaxial lesions.Methods The findings of 3DCT were analyzed and compared with conventional CT and radiography in 124 patients with atlantoaxial disease.Results 124 cases of atlantoaxial lesion included fracture in 42,atlantoaxial rotatory dislocation in 73,hypoplasia of the dens in 4,and congenital atlantoaxial deformity in 5.Among the 124 cases,89 cases were diagnosed by X-ray,109 cases by conventional CT,121 cases by MIP,122 cases by SSD,124 cases by MPR and VR.Conclusion 3DCT can find the slight rotatory dislocation,so it is the most effective means for the diagnosis of atlantoaxial rotatory dislocation.3D and MPR of spiral CT are useful in the diagnosis of atantoaxial fracture.Combining conventional CT and X-ray film with 3DCT can improve the acuracy of the diagnosis.

MSCT Reconstruction in Designing the Pedicle Screw Trajectory before Operation in Atlantoaxial Lesions / 实用放射学杂志

Objective To evaluate the clinical value of multislice spiral CT(MSCT) reconstruction in designing the pedicle screw trajectory before operation in atlantoaxial lesions.Methods 37 patients with upper cervical abnormality treated by surgery for atlantoaxial or occipitoaxial interfixation and/or fusion were undergone MSCT scan,and the 3D anatomical data(including the length,width and height of each pedicle,the angle between the pedicle and sagittal plane,and the thickness of internal occipital crest) were measured on volume reconstruction(VR) and multi-plane reconstruction(MPR) images and used for surgeon to select advisable pedicle screws(including the proper length and diameter) and to ensure the comfortable point,depth and direction for screw position at preoperation.The patients were followed up by atlantoaxial X-ray image and/or MSCT reconstruction to estimate the veracity of the screw position.Results All the patients were operated successfully,of them,5 patients were treated by simply atlantoaxial fixation,15 by atlantoaxial fixation and fusion,4 by simply occipitoaxial fixation,11 by occipitoaxial fixation and fusion,2 by atlantoaxial fixation and occipitoaxial fusion.X-ray images and/or MSCT reconstruction revealed that atlantoaxis were reposition entirely and all the screws were at predesigned trajectory.All the patients were followed up and no screw was broken or loosen and no atlantoaxial redislocation was found.Conclusion MSCT reconstruction for designing pedicle screw trajectory in atlantoaxial lesions before operation is satisfactory and valuable for clinical application.