Anatomical Study Of Anterior Approachscrew Fixation Through C2 Vertebral Body Into C1 Lateral Mass And Initial Clinical Application

Atlanto-axial joint Unsteadiness and dislocation is very commonly in clinical,it may result superior cervical cord compression,usually request operation to relief compression and stabilize atlanto-axial joint. In 1910,Mixter and Osgood succeed in fixed posterior arch of atlas and processus spinosus with silk suture,after that,many authors have researched and improved atlanto-axial joint fixation and fusion on unceasing .In a word,atlanto-axial joint fixation and fusion may through anterior and posterior approach,each of them has advantage, disadvantage and indication. Posterior approach expose easily,mounting internal fixation easily,it is prefer approach modus in clinical at present.However,it is very difficult in fixing of Swan-Neck deformity patient through posterior approach,anterior transarticular screw fixation through C2 vertebral body into C1 lateral mass first reported by Wang chao in 1999 can solve this difficult.But it can not expose atlanto-axial joint,can not direct see courser direction of screw with naked eyes.So must precise location of direction of screw in preoperation,but how to location only reported by Chen jian so far.But lack systematical empirical study.So,we measured fresh adult atlanto-axial joint samples and precise calculate direction of screw in anterior approach screw fixation through C2 vertebral body into C1 lateral mass.