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.

Abstract

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 Bone Graft (rhBMP-2 applied to an absorbable collagen sponge), as compared with an autogenous iliac crest bone graft placed inside the CORNERSTONE-SR 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 Allograft Ring) with an rhBMP-2-laden collagen carrier inside the graft along with an ATLANTIS 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.