A Prospective, Randomized, Multicenter Study Comparing Silicated Calcium Phosphate versus BMP-2 Synthetic Bone Graft in Posterolateral Instrumented Lumbar Fusion for Degenerative Spinal Disorders

Study Design. A prospective, Phase IV, multicenter, randomized study. Objective. The aim of this study was to compare vertebral fusion success rates following posterolateral fusion [(PLF)/posterolateral intertransverse fusion (PITF)] surgery. The surgical procedure combined posterior lumbar interbody fusion (PLIF) and PLF with internal fixation over one or two levels using silicated calcium phosphate (SiCaP) or bone morphogenetic protein (BMP)-2 as graft material in patients with a degenerative disorder of the lumbar spine. Summary of Background Data. Few controlled trials have evaluated the bone graft materials available to surgeons treating patients with spinal disorders, including degenerative disc disease, spondylolisthesis, and disc herniation. Methods. Following randomization, the surgical procedure consisting of PLIF and PLF with internal fixation over one or two levels was performed using SiCaP or BMP-2. No other osteoconductive/osteoinductive graft materials were permitted. Spinal fusion was assessed radiographically at <= 24 months. Clinical outcomes (pain on visual analog scale, Oswestry Disability Index, SF-36) and adverse events (AEs) were monitored. Results. One hundred three patients were enrolled. At 12 months, fusion was achieved in 25 of 35 (71.4%) of the SiCaP and 20 of 27 (74.1%) of the BMP-2 group, respectively (P = 1.000). At 24 months, the fusion rate was 78.6% and 84.8% for SiCaP and BMP-2, respectively (P = 0.5613). Clinical outcomes improved similarly in both groups over time. AEs were consistent with this surgical population. Conclusion. SiCaP was safe and well tolerated in patients with degenerative spinal disorders requiring PLF and provided fusion rates similar to BMP-2.