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.