C1 Posterior Arch Laminoplasty

Abstract

In most cases with C1–C2 instability, the spinal cord can satisfactorily be decompressed by simple reduction of C1–C2 subluxation. However, adequate decompression may not be obtainable in a small number of cases for several reasons. If cord compression and myelopathy symptoms are severe in such cases, direct decompression by resection or laminoplasty of C1 posterior arch is required. Posterior arch resection will result in poor recipient bed for bone graft when C1–C2 fusion is to be carried out as well. Even in cases where C1–C2 fusion is not required, posterior arch resection has several disadvantages. Considering these, the author has designed and performed his own technique of midline-splitting laminoplasty of C1 using a miniplate and a bone block. Surgical prudence is required to prevent hinge fracture during hinge opening or miniplate fixation. In addition, careful subperiosteal dissection of the hinge area and protection of the vertebral artery is required to prevent its injury.