Abstract: Objective To explore effect of Axis internal fixation system while decompression and fusion for the treatment of timeworn atlantoaxial dislocation with incomplete spinal cord injury.Methods 29 cases of timeworn atlanto-axial dislocation with incomplete spinal cord injury underwent decompression fusion and Axis internal fixation with a 7～46 months (mean 20 months) flowing-up.ResultsAfter treatment, all patients got completed fusion, there was no deterioration of neurofunction, and rate of JOA scores increased was 78.6%.ConclusionAxis internal fixation system can provide immediately a rigid stability and maintain axial correction for the segment ahile decompression and fusion for the treatment of timeworn atlantoaxial deslocation with incomplete spinal cord injury.

Key words: atlantoaxial dislocation, decomperssion occipital cervical fusion, internal fixation, Axis internal fixation system