上位頚髄病変に対する筋層温存手術

Abstract

The adequate expansion of C1 and C2 spinal canal is required for the treatment for upper cervical spinal cord lesion. Conventional axial laminectomy and laminoplasty can cause postoperative cervical malalignment and axial neck pain. These complications are serious, especially for younger patients, who can be subjected to progressive kyphotic deformities. Complete opening of these laminae is not necessarily demanded for the degenerative cervical disease such as cervical spondylosis, disc hernia and ossification of posterior longitudinal ligament. C2 decompression can be achieved by bell-shape osteotomy through large C2 spinous process, or undermining one of C2 from caudal edge. However, complete laminar opening is needed for upper cervical spinal tumor, especially large intradural spinal tumor or intramedullary cord tumor. The authors developed the laminar opening and reconstruction with all the muscular attachment undisturbed for upper cervical spinal cord lesion including C1-2. The secure of intermuscular space for lateral gutter is key procedure after midline splitting of C1-2. In C1, the lateral gutter is secured between rectus capitis posterior major (RCPMa) and minor muscle, or between RCPMa and obliquus capitis inferior muscle (OCI). In C2, it is secured between OCI and semispinalis cervicis muscle. The laminar flap is opened with all the muscular attachment maintained. Sufficient operative field was acquired, and make intradural manipulation easier. Muscle-preserving laminoplasty is completed with or without hydroxyapatite implant. We introduced these procedures in detail, and verified the concept of musculo-skeletal preservation under the pre-and post-operative evaluation of muscular layers related with C1 and C2.