Surgical strategies in the management of atlantoaxial dislocation in Down syndrome

Aims: To study the clinicoradiological features and treatment outcomes of atlantoaxial dislocation (AAD) in Down syndrome. Settings and Design: Retrospective case series. Subjects and Methods: A retrospective chart and radiology review of 9 Down syndrome patients with AAD managed at our center from 2007 to 2018. Statistical Analysis Used: Chi-squared/Fisher's exact test. Results: There were 4 males and 5 females (n = 9). The median age was 14 years (interquartile range [IQR]: 7-15.5). 77.7% (7/9) of patients had severe spasticity (Nurick Grades 4 and 5). The median duration of symptoms was 9 months (IQR: 5-39). The AAD was reducible in all (n = 9) cases. Eight (88.8%) patients had os odontoideum. The mean atlantodental interval (ADI) was 8.5 mm (+/- 2.9). T2W cord hyperintensity was seen in 66.6% (6/9). Posterior C1-2 transarticular fixation was done in 8 and occipitocervical fusion in 1 patient. Follow-up of more than 6 months (7-57 months) was available in 8/9 (88.9%) patients. There was a significant improvement in spasticity (n = 8, mean Nurick Grade 1.7 (+/- 1.1), P = 0.003). Follow-up radiographs (n = 8) showed good reduction and fusion. A preoperative bedbound patient with poor respiratory reserve expired at 10 months following surgery. There were no other complications. Conclusions: Posterior surgical approach for AAD in Down syndrome resulted in good alignment and fusion, with excellent clinical improvement. Patients with elevated PCO2 are poor surgical candidates and require home ventilation facility.