Long-term effects of inorganic osteogenesis-inducing scaffold versus autologous bone in lumbar interbody fusion: protocol for a non-randomized, controlled trial

Background and objective: Lumbar interbody fusion is the main surgical repair method for lumbar degenerative diseases. The best material for interbody fusion is autologous ilium, but its use is limited because of limited sources. Furthermore, autologous ilium implantation leads to the formation of osteophytes, which negatively affect bone healing. Inorganic osteogenesis-inducing scaffold material exhibits good biocompatibility and bone-inducing effects in posterior lumbar interbody fusion, with encouraging short-term outcomes. The present study will investigate the safety and long-term effects of inorganic osteogenesis-inducing scaffold materials versus autologous ilium in lumbar interbody fusion. Subjects and methods: This prospective, single-center, non-randomized, controlled trial will include 120 patients who receive treatment for lumbar degenerative diseases at the Department of Orthopedics, Beijing Tongren Hospital, Capital Medical University, China. These patients will receive lumbar repair surgery with inorganic osteogenesis-inducing scaffold materials (test group, n = 60) or autologous ilium (control group, n = 60). All patients will be followed up at 1 week, and 1 and 2 years postoperatively. This study was approved by the Medical Ethics Committee, Beijing Tongren Hospital, Capital Medical University, China (approval No. TRECKY2017-158) on September 28, 2017. Study protocol version: 1.0. All participants will provide written informed consent after fully understanding the study protocol. Results: The primary outcome measure of this study is the Oswestry Disability Index at 2 years postoperatively. The secondary outcome measures are the Oswestry Disability Index preoperatively and at 1 week and 1 year postoperatively, the Visual Analog Scale score, Japanese Orthopedic Association score, and lumbosacral angle preoperatively and at 1 week, and 1 and 2 years postoperatively, and the incidence of adverse reactions at 1 week, and 1 and 2 years postoperatively. A pilot study involving 52 patients with lumbar degenerative diseases treated during 2016–2017 revealed no significant differences between the test (n = 32, 61%) and control groups (n = 20, 39%) in the Oswestry Disability Index, Visual Analog Scale score, and Japanese Orthopedic Association score at 1 week postoperatively; at 12 months postoperatively, plain radiography revealed bony fusion in both groups. Conclusion: This study will provide evidence to validate whether inorganic osteogenesis-inducing scaffold material results in similar long-term outcomes to autologous ilium in lumbar interbody fusion. Trial registration: This study was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1900021333) on February 15, 2019.