Dome-like expansive laminoplasty for the second cervical vertebra.

The second cervical vertebra (C2) is in a pivotal position for the alignment and stability of the cervical vertebrae as a whole. Since its spinal canal is wider at the cranial and narrower at the caudal end, a dome-like excision of the inner side of the spinal canal from the caudal toward the cranial end results in the decompression of the lesion, preserving the dorsal part of the C2. The authors performed this C2 dome-like expansive laminoplasty on 33 patients (25 cases of the ossification of the posterior longitudinal ligament, six of developmental spinal canal stenosis, and two of spondylosis) and kept them under follow-up observation, which ranged from 1 to 7 years (mean, 3.5 years). The result was satisfactory in terms of the decompression and stability of the cervical vertebrae: even 5 years after the operation, no osteogenesis was noted in the expanded spinal canal to induce compression again. It thus may be concluded that this method is good enough to replace conventional laminectomy.