Abstract
Atlanto-axial rotatory fixation (AARF) is uncommon and is usually associated with a history of trauma to the neck or an upper respiratory tract infection. In patients who present early, correction of the deformity with traction and orthoses has been reported.
Owing to failure of reduction, patients presenting late (more than a month after the condition developed) have been treated with an in situ C1/C2 fusion. Follow-up of in situ fusions has shown both progression of the deformity and correction through compensatory mechanisms.
Over a five-year period seven AARF patients (16%), ranging in age from 5 to 11 years, presented more than three months after injury. All patients had a ‘cock robin’ posture and were neurologically intact. In three patients the injury was sustained in a fall from a tree and in four it was due to a motor vehicle accident. Two patients sustained additional fractures.
All patients had CT scans. In four patients MR scans and MR angiography were used to evaluate the pathology in the atlanto-axial complex, including the vertebral artery, and revealed soft-tissue interposition in the atlanto-axial joint and atlantodental interval. There was thrombosis of the vertebral artery in two patients. Clinical and radiological correction of the deformity was achieved with transoral release and skull traction, followed by fusion.
While in previous studies there has been speculation on the causes of failure of closed reduction, MRI and the transoral procedure identified the pathology in this uncommon condition.
The abstracts were prepared by Professor M. B. E. Sweet. Correspondence should be addressed to him at The Department of Orthopaedic Surgery, Medical School, University of Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
