Does Bone Marrow Aspirate Augment Bone Formation with a Hydroxyapatite Scaffold?

Introduction: Bone graft is crucial in the repair and regeneration of large or criticalsized defects and hydroxyapatite has been widely used in many clinical conditions as a bone graft substitute material. However, in the older patient group the challenges faced by the surgeon to repair and regenerate defects with good quality bone can be difficult and improved materials are needed. Bone marrow aspirate (BMA) is the most practical source of multipotent stromal cells and some studies have reported enhanced bony ingrowth within hydroxyapatite (HA) scaffolds. This study investigated the effect of the binding agent Calcium/Sodium Alginate fibre gel and the addition of autogenic BMA on bone growth into a porous HA scaffold manufactured using novel patented techniques and implanted in an ovine femoral condyle critical-sized defect. Our hypothesis was that Alginate fibre gel would have no negative effect on bone formation and osteoconduction within the scaffold and that BMA would augment the bone turnover rate and incorporation of the graft with the surrounding bone at 6 and 12 weeks post implantation.