Scott H. Kitchel, MD, Eugene, OR, USA; Reginald Q. Knight, MD, Seattle, WA, USA; J. Kenneth Burkus, MD, Columbus, GA, USARecombinant human bone morphogenetic protein (rhBMP)-2 has proven to be an effective adjunct in achieving arthrodesis in an anterior lumbar interbody model. The precise method of delivery and structural component of the interbody construct continue to require evaluation. This study looks in prospective randomized fashion at the use of rhBMP-2 in conjunction with threaded allograft bone dowels or titanium threaded fusion cages in the lumbar spine.Fifty patients were prospectively randomized into rhBMP-2 plus threaded cortical bone dowel (n=24) or rhBMP-2 plus threaded titanium fusion cage groups (n=26). Surgeries were performed at eight investigational sites. Complete follow-up data at 24 months are available on all 50 patients. Patient demographics are presented and do not differ statistically significantly between the two groups. Surgery data including operative time, blood loss and hospital stay are not statistically significantly different between the two groups.Surgical results are reported for back pain and leg pain using visual analogue scores, Oswestry Disability Index, neurological results, return to work, fusion and Short Form (SF)-36. Fusion is defined as bridging trabecular bone on plain radiograph and computed tomography, less than 3 mm translation and less than 5 mm angulation on flexion-extension radiographs, no lucent lines around the implant and no change in disc height. Fusion at 24 months was 95.5% with the threaded bone dowels and 96.1% in the titanium-threaded cages. Oswestry mean scores decreased 50% in both groups. Neurologic success was 95.8% in the threaded cortical bone dowel group and 95.0% in the titanium fusion cage group. None of these are statistically significantly different. Similarly, no other statistically significant differences were seen in the results for either group. Adverse events are reviewed.We conclude that the structural component of an anterior lumbar interbody fusion when using rhBMP-2 does not change the outcome when comparing threaded cortical bone dowels and titanium fusion cages. Therefore, either implant appears equally successful as a carrier.