Prompt diagnosis and treatment can help pediatric patients survive traumatic AOD

Traumatic atlanto-occipital dislocation is a rare injury that is often fatal. Children are at an increased risk of death with this injury because of several anatomic factors, but, according to researchers, they also make up the majority of patients who survive the injury.

Joseph Ryan Keen, DO, and colleagues analyzed the outcomes of rigid occipitocervical fusion on pediatric patients who suffered atlanto-occipital dislocation (AOD) from either a motor vehicle accident or a motor vehicle versus pedestrian accident.

“This is a survivable injury in children,” Keen said in a presentation of the results.

However, a reliable and safe fixation technique is needed in the pediatric population because a child’s spine cannot easily accommodate adult fixation techniques. Rigid occipitocervical instrumentation typically involves fixation of the occiput to C1-2 via screw and rod/wire constructs, according to Keen.

Keen and colleagues found in their retrospective review that rigid occipitocervical fusion is safe in children under 8 years of age and in children as young as 6 months of age. They studied all surviving pediatric patients diagnosed with AOD who underwent treatment between 2006 and 2014 at Loma Linda University Children’s Hospital, in Loma Linda, Calif.

“We recommend BDI (basion-dental interval) of the C1-2:C2-3 ratio, and the compound C1 interval. Pre-vertebral soft tissue swelling was particularly helpful in raising suspicion of AOD. Ligamentous injury on MRI was the most reliable, and we typically recommend early surgical stabilization with rigid internal fixation,” Keen said during his presentation. “We would add translaminar screws and rib autograft, and thus far we have not detected any spinal deformity or subaxial instability.”

Thirteen children were studied. Ten patients were injured in motor vehicle accidents and 3 patients were involved in automobile and pedestrian incidents.

Ten patients had data available for the analysis at a follow up of 21 months, mean. The patients underwent fusion using rod and/or wire constructs anchored via several types of screw fixation at a mean age of 3.83 years old. One construct failed, according to the abstract, but the patient subsequently achieved fusion.

All the patients had autograft incorporated into the constructs, Keen said. Postoperative halos were not used. Two patients had superficial wound infections which were treated with antibiotic washouts.

Keen and colleagues concluded the technique was safe for children and resulted in fusion for every patient for whom data were available. They noted that translaminar screws and rib autograft were advantageous to use in these cases due to the pediatric anatomy.

“There is a definite need to have prompt diagnosis and treatment of this condition. Children are at particularly high risk because of a disproportionately large head-to-body ratio. Their occipitals are more horizontal and shallower. They have increased ligamentous laxity and weaker cervical musculature,” he said. – by Robert Linnehan

Reference:

Keen JR, et al. Paper #832. Presented at: American Association of Neurological Surgeons Annual Meeting; April 5-9, 2014; San Francisco.

For more information:

Joseph Ryan Keen, DO, can be reached at the Department of Neurosurgery, Loma Linda University Medical Center, 11234 Anderson St., Rm. 2562-B, Loma Linda, CA 92354; email: jkeen@llu.edu.

Disclosure: Keen reports no relevant financial disclosures.