Background: Recombinant human bone morphogenetic protein-2 soaked
into an absorbable collagen sponge (rhBMP-2/ACS) has been shown in a nonhuman
primate study and in a pilot study in humans to promote new bone formation and
incorporation of an allograft device when implanted in patients undergoing
anterior lumbar interbody arthrodesis. However, a larger series with longer
follow-up is needed to demonstrate its superiority to autogenous iliac crest
Methods: Between 1998 and 2001, a two-part, prospective, randomized,
multicenter study of 131 patients was conducted to determine the safety and
efficacy of the use of rhBMP-2/ACS as a replacement for autogenous iliac crest
bone graft in anterior lumbar spinal arthrodesis with threaded cortical
allograft dowels. Patients were randomly assigned to a study group that
received rhBMP-2/ACS or to a control group that received autograft. The
clinical and radiographic outcomes were determined with use of
well-established instruments and radiographic assessments.
Results: The patients in the study group had significantly better
outcomes than the control group with regard to the average length of surgery
(p < 0.001), blood loss (p < 0.001), and hospital stay (p = 0.020).
Fusion rates were significantly better in the study group (p < 0.001). The
average Oswestry Disability Index scores, Short-Form-36 physical component
summary scores, and low-back and leg-pain scores were significantly better in
the study group (p < 0.05).
Conclusions: In patients undergoing anterior lumbar interbody
arthrodesis with threaded allograft cortical bone dowels, rhBMP-2/ACS was an
effective replacement for autogenous bone graft and eliminated the morbidity
associated with graft harvesting.
Level of Evidence: Therapeutic Level I. See Instructions
to Authors for a complete description of levels of evidence.