ENHANCING POSTEROLATERAL SPINAL FUSION WITH rhBMP-6 EXPOSED OSTEOPROGENITORCELLS

INTRODUCTION: The nonunion rate after posterolateral fusion has been reported to be as high as thirty-five percent, even with the use of autogenous iliac crest bone graft (ICBG) [4]. Accordingly, alternative techniques for expanding or stimulating the spinal fusion process are actively being investigated [1]. For the past several years we have been developing a strategy for stimulating marrow-derived osteoprogenitor (OP) cells by exposure to a cell-derived osteoinductive matrix containing rhBMP-6. Our preliminary data suggests that this exposure induces osteoblastic differentiation [4] and that the induced cells are capable of increasing new bone formation in the New Zealand white rabbit (NZW) posterolateral intertransverse fusion model [6]. In this study we have expanded our prior work [6] to assess the osteogenic capacity of two different concentrations of rhBMP-6 exposed osteoprogenitor cells.