New double-door laminoplasty procedure for the axis to preserve all muscular attachments to the spinous process: technical note.

To prevent the occurrence of postoperative cervical malalignment, which is often a complication of conventional axial laminectomy or laminoplasty, the authors developed a new double-door laminoplasty procedure in which the C-2 spinal canal is expanded while all the muscular attachments to each split half of the spinous process remain undisturbed. In conjunction with laminoplasties at other levels, this procedure was performed in five patients with ossification of the posterior longitudinal ligament and cervical myelopathy. Neurological improvement was demonstrated in each patient, and there was no radiological evidence of cervical malalignment. The technique for this procedure is described and its usefulness in preventing postoperative spinal malalignment is discussed.