Augmentation of Rabbit Posterolateral Spondylodesis Using a Novel Demineralized Bone Matrix-Hyaluronan Putty

Abstract

Posterolateral spinal fusion with allogeneic demineralized bone graft-hyaluronan putty in addition to autogenous iliac crest bone graft in a rabbit model. To determine the potential efficacy of demineralized bone graft-hyaluronan putty as a bone graft enhancer. Autograft bone is the material of choice for posterolateral lumbar intertransverse process fusion. Bone graft alternatives such as demineralized bone matrices that can be used as graft extenders, enhancers, or substitutes continue to be developed. One hundred New Zealand white rabbits underwent bilateral posterolateral spinal fusion with autogenous iliac crest bone graft or bone graft with allogeneic rabbit demineralized bone graft-hyaluronan putty. The rabbits were killed 9 weeks later, and the lumbar spines were removed. Manual manipulation and fine detail radiography were used to assess spinal fusion, and computed tomographic images were used to quantify the volume of the fusion mass. In comparison with autograft bone alone, the fusion rates were greater when demineralized bone graft-hyaluronan putty was used as an adjunct to autogenous bone. Furthermore, the radiographic fusion rate was greater when demineralized bone graft-hyaluronan putty was used in a 2:1 ratio to autograft bone in comparison with a 1:1 ratio (P = 0.001). The addition of demineralized bone graft-hyaluronan putty to autograft bone was found to increase mineralized bone volume in a ratio-dependent manner (P < 0.05). Allogeneic demineralized bone matrix-hyaluronan putty enhances rabbit posterolateral spine fusion when used as an adjunct to autogenous bone graft. This new formulation of demineralized bone matrix may facilitate greater bone formation and successful fusion.