The Efficacy of Three Different Commercially Available Demineralized Bone Matrices for Inducing an Intertransverse Spinal Fusion in a Rat Model

· (a – Musculoskeletal Transplant Foundation)

This study directly compared the efficacy of three different demineralized bone matrix (DBM) products for inducing spinal fusion in a rat model. Athymic rats were implanted with Allomatrix (Wright Medical), DBX (MTF), or Grafton (Osteotech). L4 and L5 transverse processes were decorticated and 0.3 cc of graft was implanted bilaterally. Animals were sacrificed at 2, 4, and 8 weeks, at which time radiographic, histologic, and biomechanical analyses of the explanted spines were performed.

Using a radiographic scoring system, no spines were fused at 2 weeks. At 4 and 8 weeks the Grafton and DBX groups had more radiographic fusions than Allomatrix but a significant difference was only noted between Grafton and Allomatrix (p<0.05). Manual testing revealed that the Grafton group fused more frequently than the DBX and Allomatrix groups at 4 weeks and 8 weeks. This study demonstrates that there are differences in the osteoinductive potentials of commercially available DBMs.