A refined method of en bloc open-door laminoplasty for resection of intradural spinal tumors in the thoracic and lumbar spine.

Background: The open-door laminoplasty has been used to treat cervical spondylotic myelopathy. This technique has been applied to the surgical treatment of thoracic and lumbar spinal canal tumors instead of simple laminectomy or hemilaminectomy. However, previously reported laminoplasty methods did not keep posterior supporting elements intact such as the laminae and the spinous processes with supraspinous and interspinous ligaments, and almost all of them needed instruments for the fixation of reconstructed laminae. The purpose of this paper is to introduce our open-door laminoplasty method, which keep all posterior supporting elements intact and reconstruct the laminae without instrument.
Methods: Eight patients (mean age 61 years) underwent en bloc open-door laminoplasty in the thoracic and lumbar spine for resection of intradural spinal tumors. Two grooves are made bilaterally on the laminae just medial side of the facet joints. One-half of each spinous process of the adjacent vertebrae above and below the laminoplasty is cracked diagonally to create a green stick fracture and bent to the hinged side for sufficient elevation of the laminar flap. After tumor resection, the laminar flap is restored to its original site, resulting in the complete preservation of the posterior supporting elements.
Results: Operative exposure was good and permitted complete resection. No complications such as postoperative spinal canal stenosis or kyphosis were observed. Computed tomography(CT) indicated that bony fusion occurred in all cases.
Conclusion: The supraspinous and interspinous ligaments above and below laminoplasty were kept intact during surgery in our method. Therefore, the continuity of posterior supporting elements (laminae and spinous processes connected by supraspinous and interspinous ligaments) were completely preserved.
Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest.
(Copyright © 2020 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)