Atlantoaxial Instability in Children, 26 Years of Experience

Study Design: Retrospective case study.

Objective: To determine the history, clinical and imaging signs, diagnosis, treatment and clinical follow-up.

Summary of Background Data: The cranio vertebral junction (CVJ) is a complex transitional area between the skull, the upper cervical spine, the brain and the upper cervical cord. It concerns all ages. Instability can be the result of congenital malformations or traumatic injury.

Methods: It is a retrospective study of patients files in department of paediatricneurosurgery and the department of pediatric orthopedic of Marseille, during 26 years , Between 16th October 1981 and 16th June 2007 In each medical record, we determined identity, circumstances of instability discovery, clinical and paraclinical signs, diagnosis, therapeutic protocol and patient's outcome after treatment.

The inclusion criteria were the medical records with complete information regarding the patients, who were treated for atlantoaxial instability (AAI). Patients presenting clinical instability with incomplete files, have been excluded.

Results: In our retrospective study, 22 children have been treated for AAI, with 10 boys (45%) and 12 girls (55%), aged 5 to 17 years old, mean age was 10.

the main circumstance of lesion was accident 45,5%, sport accident 27,3%, road accident 18,2%), the others circumstances are 55,5%.

The past history included : congenital malformation in 18,2% (Down’s syndrome, Klippel- Fiel’s syndrome, cardiac malformation), sport accident(9,0%), neurological deficit (13,7%), cervical trauma already treated(4,5%), learning deficit (4,5%), and plagiocephaly (4,5%); for 45,6%, there was no evidence etiology.

The clinical signs were quadriparesis (31,9%), quadriplegia (13,6%), torticoli (9,1%), quadriplegia and priapism (4,5%), headache and dizziness (4,5%), abnormal head position attitude (4,5%). Clinical exam was normal for 31,9%.

Standard X-ray was performed for 50,0%, CT scan for 50,0% and MRI for 40,8%.

These paraclinical examination showed that AAI were traumatic in 59,1% (luxation 36,4%, odontoïdum fracture 13,7%, C1C2 dislocation 4,5 %, C2 arch, articular fracture and pseudoarthrosis 4,5%), congenital malformation in 40,9%.

The orthopedic treatment was used for 13,5% of the patients and surgical treatment was used for 86,5% of the patients (posterior approach72,8 %, anterior approach 9,2%, anterior and posterior approach 4,5%).

Complications were observed in 33% of the patients (consisted of infections 14%, Medulla oblongata compression 5%, basilar impression)

72% of the patients recovered without sequela after 15years of follow up, 28% had a neurological deficit during the same time .13% conserved their deficit 5 years after treatment.

Conclusion: In many cases, AAI is an insidious affliction in many cases. A neurological deficit is a sinister presentation often leading to significant sequela even after treatment.