Bone Regeneration Within a Coralline Hydroxyapatite Implant

Spinal fusion using an autologous growth factor gel and a porous resorbable ceramic

“…Coralline-derived bone graft substitutes provide a scaffold for bone growth similar to that of native trabecular bone [4,11,27,41,42,45]. Unlike autograft, osteoconductive bone graft substitutes are limited since they neither contain the native osteoinductive molecules (BMPs and growth factors) present in autologous bone nor the undifferentiated mesenchymal cells and blood-related products that facilitate healing [20].…”

“…Biomaterial bone graft substitutes, including a variety of hydroxyapatite [3,24,25,27,36] and composite-based materials, [36,43] have been developed to replace autogenous bone, with varied success. Whilst bone graft substitutes can provide a matrix for cellular ingrowth/ongrowth or a scaffold for new bone formation, they lack the biological molecules and cells present in the normal healing environment [20].…”

Mediation of bone ingrowth in porous hydroxyapatite bone graft substitutes

“…8 It is not surprising that the physical properties, such as the mechanical behaviour and the pore architecture, of the various porous calcium-phosphate products vary widely. [1][2][3]9,10 The potential of these materials has been recognised for some years, 6,7,[11][12][13] and there have been a number of investigations into the effect of pore structure on the repair process. 6 -12,14 -20 However, because of varying methods and degrees of quantification in both the pore structure and the volume or rate of bone apposition, there is still much confusion about the mechanisms behind bone ingrowth, or osseointe-gration, within macroporous structures.…”

“…6 -12,14 -20 However, because of varying methods and degrees of quantification in both the pore structure and the volume or rate of bone apposition, there is still much confusion about the mechanisms behind bone ingrowth, or osseointe-gration, within macroporous structures. A pore size Ͼ 100 m is often cited as a minimum requirement for healthy, sustainable bone ingrowth 7,9,11 and many studies report a dependence between volume or rate of integration and pore size. 7,9,11,12,14,16 However, other researchers promote the importance of additional structural parameters, such as pore morphology, percent porosity, and pore connectivity, 6,[17][18][19][20] whereas a minority dispute the role of structure at all.…”

“…11,18,28 Osteoconduction can be defined as the ability of a material to encourage bone to grow toward and along its surface, whereas osteoinductive materials possess the additional ability to trigger the spontaneous apposition of new bone directly on their surfaces via the differentiation of local stem cells into active boneforming cells. The prerequisite for an osteoconductive/osteoinductive material, therefore, limits the choice in scaffold material for a bone graft substitute to a group of calcium-phosphate (Ca-PO 4 )-based ceramics, glasses, and glass-ceramics, for which the fabrication of high-porosity, foamlike structures presents a particular challenge.…”