Drawings of thoracic spine before and after repeated laminectomy show effects on growth of vertebral bodies. A, Before laminectomy, anterior vertebral bodies are rectangular in configuration. B, Spine that has had multiple laminectomies will have increased compression anteriorly because of loss of posterior supporting structures. This compression results in less growth in anterior portion of vertebral body than in posterior portion. In time, this will result in wedging of vertebral bodies, causing kyphotic deformity.