Abstract
Purpose
Bone morphogenic protein (BMP-2) is used in spinal arthrodesis to induce bone growth. Studies have demonstrated that it achieves similar fusion rates compared to iliac crest bone graft when used in instrumented fusions. Our study aims at evaluating the requirement for instrumentation in one and two-level spinal arthrodeses when BMP-2 is used in conjunction with local bone to achieve fusion.
Method
50 patients were recruited and randomized to instrumented versus non-instrumented spinal arthrodesis. BMP-2 with local autologous bone was used in all patients. Patients are evaluated at 3-months, 6-months, 12-months, and 24-months postoperatively with questionnaires to assess clinical outcome (ODI, VAS and SF-36), and PA and lateral x-rays of the spine to assess radiographic fusion (Lenke score). At 24 months, a thin-cut (1mm) CT scan was performed.
Results
Two-year data is available on 40 patients. There were no statistically significant differences between the two groups based on the clinical outcomes measured. The ODI 22.55.1 for the instrumented group vs. 13.733.57 for the non-instrumented group (p=0.2)). The VAS for the instrumented group was 2.110.61 vs. 1.530.61 for the non-instrumented group (p=0.49). The SF-36 (physical) was 62.316.71 for the instrumented group vs 54.665.43 for the study group (p=0.8). The operating time was 105.85.91 minutes for the instrumented group versus 88.63.61 minutes for the non-instrumented group (p=0.01). Blood loss was 339.139.38 cc for the instrumented group vs 273.133.8 cc for the non-instrumented group (p=0.1). Preliminary radiographic analysis showed similar fusion rates for the two groups. Two-year follow-up on all patients will be completed by February 2010. Final clinical and radiographic data analysis will be presented at the meeting.
Conclusion
BMP-2 and local bone graft demonstrated functionally equivalent clinical outcomes when used with or without instrumentation in lumbar spinal fusions while offering potential reduction in operative time and blood loss.
