Modified posterior transarticular screw fixation for atlantoaxial instability / 中国矫形外科杂志

ABSTRACT

[Objective]To explore the techniques and effect of atlantoaxial instability with posterior transarticular screw fixation.[Method]A prospective clinical analysis was performed for the results of the modified posterior C1、2 transarticular screw fixation,in which the middle site of lower margin in the axial inferior articular process was used as the screw entry point in the procedure.Twenty cases of atlantoaxial instability underwent the modified C1、2 stabilization with morselized autograft from September 2001 to September 2006.There were 15 males and 5 females,averaged 32.2 years(range 17 to 49 years).Of them,4 cases suffered from fresh injuries,14 from old trauma,1 from congenital deformity,and 1 from intraspinal tumor.Postoperative indexes including the reduction extent of vertebral body,internal fixation,bone fusion,clinical symptoms and their complication were observed periodically.[Result]Bilateral screw fixation was used alone in 17 cases,with Gallie interspinous wiring for added stability in 3.Anatomical reduction of the atlantoaxial joints was achieved in19 cases,while rotational dislocation was restored to a great extent in 1.Fixation of all the internal devices was very well in the group.All cases were followed up from 16 to 64 months(21 months on average).C1、2 bony fusion was obtained in postoperative 2 to 3 months,clinical symptoms relieved and no complications occurred.[Conclusion]The modified posterior transarticular screw fixation using new screw entry site is recommended as an effective treatment for C1、2 instability due to its simple procedure and satisfying curative effect.