Original Research
Effects of Recombinant Human Bone Morphogenetic Protein 2 on Surgical Infections in a Rabbit Posterolateral Lumbar Fusion Model
Am J Orthop. 2009 November;38(11):578-584
Author and Disclosure Information
Christopher P. Miller, BA, Andrew K. Simpson, MD, Peter G. Whang, MD, Benjamin P. Erickson, BA, Walid R. Waked, MD, James P. Lawrence, MD, and Jonathan N. Grauer, MD
Mr. Miller is Medical Student, Yale University School of Medicine, New Haven, Connecticut.
Dr. Simpson is Orthopaedic Resident, Harvard Combined Orthopaedics Program, Boston, Massachusetts.
Dr. Whang is Assistant Professor, Mr. Erickson is Medical Student, Dr. Waked is Research Fellow, Dr. Lawrence is Orthopaedic Resident, and Dr. Grauer is Associate Professor, Yale University School of Medicine, New Haven, Connecticut.
Recombinant human bone morphogenetic proteins (rhBMPs) are often used during spine surgery, but their effects on postoperative infections have not been well elucidated. Long-bone studies suggest that BMPs may limit local infection and facilitate bone formation. Until now, rhBMP-2 had not been evaluated in the setting of infected spinal arthrodesis. In the study reported here, we evaluated the safety and efficacy of rhBMP-2 and autograft in inducing fusion in the setting of surgically acquired infection.
Sixty rabbits underwent fusion with autograft or rhBMP-2 with coadministration of Staphylococcus aureus or sterile saline. In the noninoculated groups, 4/15 autograft and 13/13 rhBMP-2 rabbits fused (P<.001). In the inoculated groups, 0/14 autograft and 3/12 rhBMP-2 rabbits fused (P = .085). There were 4/14 early deaths caused by infection in the autograft group and 0/12 in the rhBMP-2 group (P = .1). Although the difference in fusion rates and early deaths from infection for rhBMP-2 and autograft did not reach our predetermined α error threshold, the data were trending toward significance.
Our results demonstrated no increase in morbidity or mortality associated with use of rhBMP-2 in the setting of local infection. Although BMP use with infections remains controversial, these results indicate that rhBMP-2 could be used in a contaminated environment.