Introduction: Spinal canal expansion via open-door-laminoplasty (ODL) is an alternative to multilevel cervical laminectomy with or without instrumented fusion. Techniques for creating and maintaining increased sagittal-cervical-canal-diameter contribute significantly to patient outcome. The purpose of this study is to present operative nuances of an ODL technique utilized at our institution. Our investigation provides insight to long-term outcomes related to the degree of spinal canal expansion and techniques that help maintain stable canal dimensions.
Methods: We performed a retrospective cohort study of patients undergoing a refined ODL technique(2006-2013). Preoperative and postoperative spinal canal dimensions were measured at each cervical level. Long-term clinical outcomes were assessed using Nurick myelopathy classification and neck disability index. Surgical nuances include the use of a B1 drill bit and footplate on the “open-door” side, to make a full thickness groove through bone and ligamentum flavum in a single maneuver. Titanium mini-plates are bent at ~110-degree-angles at each end (Z-shape), and secured to connect the lamina and facet, stabilizing posterior elements with canal expansion.
Results: All patients treated with this technique had multilevel cervical canal stenosis secondary to spondylosis or ossified posterior longitudinal ligament (OPLL). Mean follow-up was 34-months. There was 1 single-segment, 9 three-segment, 17 four-segment, and 1 five-segment case. Average sagittal-canal-diameter was increased by 30-50% at each surgical level. Postoperatively, all patients experienced clinical improvement long-term; however, OPLL patients had more acute improvements in clinical condition than cervical spondylosis patients. No patients required re-operation, or experienced restenosis of the canal, re-closure of the lamina, or failure of mini-plate constructs.
Conclusions: Canal expansion is maximized with the use of the B1 drill bit and footplate by minimizing bone loss, thereby augmenting the canal perimeter created with the use of mini-plates. Use of titanium mini-plates stabilizes posterior elements and maintains dimensions of the decompressed spinal canal long-term.
Patient Care: Our research provides nuances of operative techniques in cervical laminoplasty that contribute to decreasing overall operative or procedure time and thereby overall blood loss. These techniques also prevent the need for re-operation by more effectively preventing restenosis of the cervical canal or re-closure of the lamina.
Learning Objectives: • To understand operative nuances of cervical laminoplasty
• To consider techniques of cervical canal expansion and its role in the long-term outcomes of patients undergoing cervical laminoplasty
• To be able to identify patients whose cervical pathology can best be treated with the described cervical laminoplasty techniques