Chi Heon Kim1,2, Chun Kee Chung1,2,3,4, Yunhee Choi5, Calvin C Kuo6, Urim Lee4, Seung Heon Yang1,2, Chang-Hyun Lee1,2, Jong-Myung Jung7, Sung Hwan Hwang1,2, Dong Hwan Kim1,2, Joon Ho Yoon1,2, Seoi Paik1,8, Hwa Jin Lee1,8, Sunhyang Jung1,8, Sung Bae Park1,2,9, Kyoung-Tae Kim10,11, Hee-Pyoung Park12,13. 1. Department of Neurosurgery, Seoul National University Hospital, Seoul, South Korea. 2. Department of Neurosurgery, Seoul National University College of Medicine, Seoul, South Korea. 3. Department of Brain and Cognitive Sciences, Seoul National University Hospital, Seoul, South Korea. 4. Human Brain Function Laboratory, Department of Neurosurgery, Seoul National University Hospital, Seoul, South Korea. 5. Division of Medical Statistics, Medical Research Collaborating Center, Seoul National University Hospital, Seoul, South Korea. 6. Regional Spine Surgery Department, Kaiser Permanente, Oakland, California. 7. Department of Neurosurgery, Seoul National University Bundang Hospital, Kyung-gi, South Korea. 8. Department of Nursing, Seoul National University Hospital, Seoul, South Korea. 9. Department of Neurosurgery, Seoul National University Boramae Hospital, Boramae Medical Center, Seoul, South Korea. 10. Department of Neurosurgery, Kyungpook National University Hospital, Daegu, South Korea. 11. Department of Neurosurgery, School of Medicine, Kyungpook National University, Daegu, South Korea. 12. Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, South Korea. 13. Department of Anesthesiology and Pain Medicine, Seoul National University College of Medicine, Seoul, South Korea.
Abstract
BACKGROUND: In cervical open-door laminoplasty for cervical myelopathy, a high-speed rotatory drill and rongeurs are used to make unicortical troughs and bicortical openings in the laminae. The lamina is reflected at the trough to enlarge the spinal canal, followed by bone healing on the hinge side to stabilize laminoplasty. The ultrasonic bone scalpel (UBS) has been used due to theoretical advantages including a better hinge union rate, less soft tissue trauma, less neurological injury, and shorter operative time. OBJECTIVE: To assess the superiority of UBS for hinge union compared to the drill through randomized controlled trial. METHODS: In 190 randomly allocated cervical myelopathy patients, the trough and opening at the lamina were made using either the drill (n = 95) or UBS (n = 95) during 2015 to 2018. The primary outcome was the hinge union rate on 6-mo postoperative computed tomography. Secondary outcomes included the hinge union rate at 12 mo, the operative time, intraoperative/postoperative bleeding, neurological injury, complications, and clinical outcomes over a 24-mo follow-up. RESULTS:Hinge union in all laminae was achieved in 60.0% (drill) and 43.9% (UBS) of patients at 6 mo (intention-to-treat analysis; P = .02; odds ratio, 2.1) and in 91.9% (drill) and 86.5% (UBS) at 12 mo. Dural injury only occurred in the drill group (2.1%), and the UBS group showed significantly less intraoperative bleeding (P < .01). The other secondary outcomes did not differ between groups. CONCLUSION: The hinge union rate was inferior in the UBS group at 6 mo postoperatively, but UBS was efficacious in reducing dural injuries and bleeding.
RCT Entities:
BACKGROUND: In cervical open-door laminoplasty for cervical myelopathy, a high-speed rotatory drill and rongeurs are used to make unicortical troughs and bicortical openings in the laminae. The lamina is reflected at the trough to enlarge the spinal canal, followed by bone healing on the hinge side to stabilize laminoplasty. The ultrasonic bone scalpel (UBS) has been used due to theoretical advantages including a better hinge union rate, less soft tissue trauma, less neurological injury, and shorter operative time. OBJECTIVE: To assess the superiority of UBS for hinge union compared to the drill through randomized controlled trial. METHODS: In 190 randomly allocated cervical myelopathypatients, the trough and opening at the lamina were made using either the drill (n = 95) or UBS (n = 95) during 2015 to 2018. The primary outcome was the hinge union rate on 6-mo postoperative computed tomography. Secondary outcomes included the hinge union rate at 12 mo, the operative time, intraoperative/postoperative bleeding, neurological injury, complications, and clinical outcomes over a 24-mo follow-up. RESULTS: Hinge union in all laminae was achieved in 60.0% (drill) and 43.9% (UBS) of patients at 6 mo (intention-to-treat analysis; P = .02; odds ratio, 2.1) and in 91.9% (drill) and 86.5% (UBS) at 12 mo. Dural injury only occurred in the drill group (2.1%), and the UBS group showed significantly less intraoperative bleeding (P < .01). The other secondary outcomes did not differ between groups. CONCLUSION: The hinge union rate was inferior in the UBS group at 6 mo postoperatively, but UBS was efficacious in reducing dural injuries and bleeding.