Congenital absence of posterior elements of axis: a report of two cases

Abstract

We report two extremely unusual and remarkably similar patients having complete absence of all posterior elements of the axis vertebra and mobile, partially reducible dislocation of the axis over the third cervical vertebra. Anterior decompression followed by a fixation procedure appears to be a satisfactory form of treatment for this complex clinical problem.

• Axis
• craniovertebral anomaly
• spina bifida
• spinal dislocation