RESUMEN
Objective To study the operative strategy of congenital atlantoaxial dislocation(CAAD)-induced Chiari malformation and (or) syringomyelia. Methods The operation in reported 23cases of CAAD-induced Chiari malformation and (or) syringomyelia was composed with the transoral resection of odontoid process to achieve anterior decompression at first stage and occipito-cervical bone grafting fusion at second stage. Results MRI examination revealed the tonsils ascent and (or) syrinx reduction in 19 cases after first-stage operation. Compared with their preoperative manifestations, 14cases were obviously improved and 5 improved to some extent after operation, while 4 were unchanged. Conclusions CAAD is the main cause of tonsils descent and (or) syringomyelia in the series of patients. After anterior decompression by transoral resection of odontoid process, most patients will get recovered in tonsils descent and (or) syringomyelia reduction. The main aim of posterior operation is to reconstruct the stability of craniovertebral junction.