Flexibility and alignment of the cervical spine after laminoplasty for spondylotic myelopathy. A radiographic study.

The long term effects of laminoplasty on cervical movement and alignment were investigated by radiography and CT scans in a study of 56 patients with multisegmental myelopathy who had undergone a C3 to C7 open-door laminoplasty. Follow up averaged 5.8 years. Satisfactory neurological improvement occurred in 73%. Cervical flexion decreased by 35% and extension by 57%; the decrease of both movements was statistically significant. Decreased vertebral slip, as well as slightly reduced lordosis, was seen after operation. Increase in measured canal size after operation and at follow up was 48% and 40%; 8% of the expanded canal size was lost at the last follow up. Expansive open-door laminoplasty leads to a better neurological prognosis in this group of patients, while maintaining an increase in canal size and preserving spinal stability.