Bone-to-Bone Ligament Preserving Laminoplasty with Ultrasonic Osteotome Assistance for Intraspinal Tumors: A Technical Note and Clinical Follow-Up.

OBJECTIVE: Laminectomy has been widely used for intraspinal tumor resection. However, the tilted spinous process and narrow lateral laminae of the thoracic spine along with the hypertrophic ligamentum flavum of the lumbar spine pose certain problems for the laminae removal of the traditional laminectomy. We improved the laminectomy method with ultrasonic osteotome to treat thoracolumbar tumors and assessed its safety and superiority. METHODS: A retrospective analysis was performed in 86 patients with thoracolumbar (T4-L5) spinal tumors treated by resection, including 44 with the lamina removed using the traditional method and 42 with the lamina removed using the bone-to-bone ligament preserving (BLP) laminoplasty, which preserves the posterior ligament complex. Age, sex, and tumor size, location, and depth were compared between the two groups. The length of incision and bone window, time to remove the vertebral lamina, and epidural effusion volume were recorded at 2 weeks after surgery in the two groups. Postoperative reexamination by magnetic resonance imaging (MRI) at 2 weeks and 3 months after surgery was compared with preoperative MRI to assess the change in vertebral lamina displacement. RESULTS: There were no statistical differences in age, sex, and tumor size, depth, or location between the two groups. The BLP laminectomy did not increase the risk of dural, spinal cord, or nerve injuries. The difference between the incision and tumor length, as well as the difference between the bone window and tumor length in the BLP laminectomy group, were smaller than those in the traditional laminectomy group, and the BLP laminectomy took less time compared to that of the traditional laminectomy (p < 0.05). There was no significant difference in the volume of epidural effusion between the two groups at 2 weeks postoperatively, or in the displacement of the returned vertebral plate observed in sagittal and axial positions. The same was true for the displacement at 3 months postoperatively in the axial position. However, the sagittal displacement in the BLP laminectomy group was smaller than that in the traditional laminectomy group (p < 0.05). CONCLUSIONS: The BLP laminectomy is safe for the resection of thoracolumbar spinal canal tumors. It is less traumatic and faster, with less displacement of the returned lamina, resulting in a stable repair of the spine.