[Objective]To analyze the mechanics of neotype retropharyngeal cervical hook - plate (RCHP) for atlantoaxial instability with biomechanical testing.[Methods]Six fresh adult craniocervical specimens (C_(0~3)) used for testing the biomechanical instability were all putted into following five test courses: intact, instability (Type Ⅱ Odoutoid fracture), RCHP,Anterior C_(1、2)transarticular screw fixation, brooks. Repeated statistical analysis of the data was performed using the SPSS 13.0 software package. Measures were performed with SNK testing...