A prospective, randomized, controlled cervical fusion study using recombinant human bone morphogenetic protein-2 with the CORNERSTONE-SR™ allograft ring and the ATLANTIS™ anterior cervical plate

Study Design. A prospective, randomized, pilot clinical trial compared recombinant human bone morphogenetic protein-2 (rhBMP-2) with iliac crest autograft bone for the treatment of human cervical disc disease. Objective. To examine the safety and effectiveness of using INFUSE(TM) Bone Graft (rhBMP-2 applied to an absorbable collagen sponge), as compared with an autogenous iliac crest bone graft placed inside the CORNERSTONE-SR(TM) fibular allograft, in anterior cervical discectomy and interbody fusion. Summary of Background Data. Recombinant human bone morphogenetic protein-2 is an osteoinductive protein that induces a reliable fusion in the lumbar spine, but it has not been studied in patients with degenerative cervical disc disease. Methods. For this study, 33 patients with degenerative cervical disc disease were randomly assigned to investigational or control groups. The investigational group received a fibular allograft (CORNERSTONE-SR(TM) Allograft Ring) with an rhBMP-2-laden collagen carrier inside the graft along with an ATLANTIS(TM) anterior cervical plate. The control group received a fibular allograft with cancellous iliac crest autograft placed inside it, along with an ATLANTIS anterior cervical plate. The patients underwent plain radiographs at 6 weeks, then at 3, 6, 12, and 24 months, and CT scans at 3 and 6 months after surgery. They also completed general health profiles and self-evaluation scales. Adverse events were evaluated for severity, duration, association with the implant, and the need for a second surgical procedure. Results. All the patients evaluated had solid fusions 6, 12, and 24 months after surgery. There were no device-related adverse events. At 24 months, the investigational group had mean improvement superior to that of the control group in neck disability and arm pain scores (P < 0.03 each). Conclusions. This pilot study demonstrates the feasibility of using rhBMP-2 safely and effectively in the cervical spine.