Progressive anterior vertebral bars: a study of 16 cases

In a retrospective study, we report on 16 patients with congenital kyphosis due to progressively ossifying anterior unsegmented bars.

To specify the therapeutic strategy in such malformation.

Congenital kyphosis due to progressively ossifying anterior unsegmented bars is a particular and uncommon entity of congenital kyphosis. Progressive anterior vertebral bars result in slowly progressive kyphosis, which rarely lead to neurological compromise. Sagittal equilibrium of the spine is maintained by compensatory curves adjacent to the primary curve.

All patients had clinical assessment and successive measurements of segmental angle made on a standing lateral radiograph of the spine. Magnetic resonance imaging was obtained in four patients. Six patients were just observed. A brace was used in three. And seven were treated surgically.

The compensatory capacity of the spine is reduced in lumbar area where there are few discs spaces below the bar. Presentation therefore tends to be at an earlier age and pain is more common.Magnetic resonance imaging enables definition of the structures immediately posterior to the bar and provides information regarding the integrity of the intervertebral disc.

There is usually no need for surgery in thoracic and thoracolumbar localization. In lumbar localization, if the diagnosis is done early in childhood and if magnetic resonance imaging shows beyond the anterior ossification a normal T2-weighted magnetic resonance imaging disc space signal, desepiphysiodesis bar resection and cement interposition is mandatory. If the disc magnetic resonance imaging signal is abnormal or if the disc space is totally ossified, we propose a surgical correction of the kyphosis. For such cases a posterior wedge osteotomy seems to be the more suitable procedure.