Individualized treatment of the atlantoaxial dislocation in craniovertebral junction abnormalities

OBJECTIVES: To analyze the clinical characteristics of the atlantoaxial dislocation (AAD) in craniovertebral junction (CVJ) abnormalities and to study the setup of its surgery strategy. METHODS: From April 2009 to November 2011, 56 patients of AAD and CVJ abnormalities including 22 male and 34 female patients who had received surgery were analyzed. There were 2 cases of reducible AAD and 54 cases of irreducible AAD. The age of the patients ranged from 9 to 56 years (mean 34 years). Among them, 14 cases achieved reduction/partial reduction via direct posterior fixation, 41 cases had transoral anterior deconpression and occipito-cervical/C₁-C₂ fusion and 1 case had the posterior odontoidectomy and spinal fusion. RESULTS: Fifty-three cases had a follow-up between 6 months and 36 months (mean 20 months) and 3 cases lost follow-up (had improvement at discharge). Seven cases had complications as follows: 1 case had irreversible spinal cord injury and muscle weakness of extremities, 2 cases had cerebrospinal leak, 2 cases had pulmonary infection, 1 case had local granuloma hyperplasia and 1 case had delayed healing of the incision. The later 6 cases all got recovery after reasonable treatments. The grades of Nurick at last follow-up were as follows: 6 cases (11.3%) improved by 3 grades, 30 cases (56.6%) improved by 2 grades, 13 cases (24.5%) improved by 1 grade, 3 cases (5.7%) without change, 1 case (1.9%) get worse. CONCLUSIONS: Reducible AAD could achieve direct reduction and fixation via posterior pathways. Irreducible AAD needs individualized treatment. To choose the direct reduction and fixation or transoral odontoidectomy and posterior fixation and fusion should consider the pathogenetic condition, the image data and personal clinical experience.