Evaluation of DBM/AM composite as a graft substitute for posterolateral lumbar fusion

Demineralized bone matrix (DBM) has been investigated as a bone graft substitute for spinal fusion with less morbidity. Various carriers have been added to DBM to enhance its handling characteristics. This study investigates the spinal fusion induced by a composite of DBM and acellular dermal matrix (AM) in comparison with autologous bone in an athymic rat spinal fusion model. Single‐level intertransverse process fusions were performed in 60 athymic nude rats grafted with 2 mL/kg of DBM/AM composite, AM alone, or autologous bone. Fusion was assessed at 6 weeks by radiography, manual palpation, and histology. At 6 weeks, 70% of the animals from the DBM/AM composite group exhibited complete spine fusion, whereas 35% from the autologous bone group and 20% from AM group showed bridging with some gaps. The DBM/AM composite induced a significantly higher fusion rate than both the autologous bone and AM groups ( p << 0.001) in all measured parameters. The current study demonstrated that using DBM/AM composite can have more robust fusion than autologous bone at 6 weeks in an athymic rat spinal fusion model. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2006.