A Novel Nano-Synthetic Hydrophilic Bone Graft (OsteoFlo HydroFiber) Is a Non-inferior Alternative to Iliac Crest Autograft in a Rabbit Posterolateral Fusion Model

Study Design Experimental. Objectives The objective of the study was to evaluate the in vivo performance of SurGenTec OsteoFlo HydroFiber TM (OF-HF) (test material), compared to autograft (ICBG) in an established posterolateral spine fusion rabbit model. The test material was evaluated as a stand-alone and extender product with autograft (1:1). Methods Sixty-nine skeletally mature male New Zealand white rabbits underwent a single-level bilateral posterolateral intertransverse process spinal fusion at the L5-L6 level. Animals were randomly assigned to one of three groups: ICBG, ICBG + OF-HF, or OF-HF. Outcomes were assessed at 4 (N = 5/group), 8 (N = 8/group), and 12 weeks (N = 10/group) evaluating for spine fusion rate, new bone formation, graft resorption, and inflammatory response using radiographic, microCT, biomechanical, and histological endpoints. Results In general, all animals appeared to be in good health both at the start and conclusion of the study. All previously mentioned fusion assessment methods at 12 weeks demonstrated a 60% fusion rate for the ICBG and OF-HF groups, while the ICBG + OF-HF group demonstrated a 50% fusion rate. MicroCT morphometric analysis showed the OF-HF groups to have a significantly greater bone volume ( P < 0.05) at 12 weeks compared to the ICBG group. Conclusions The comparable fusion rates, combined with the significantly increased bone volume in both groups containing OF-HF at the 12-week interval demonstrates the OF-HF graft to be a non-inferior alternative to ICBG for stand-alone use or as an autograft extender.