Physiology of Bone Repair and Fusion
The use of a bone graft for purposes of achieving arthrodesis is affected by each of the aforementioned anatomical, histological, and biochemical principles. Additionally, several physiological properties of bone grafts directly affect the success or failure of graft incorporation. These properties are osteogenesis, osteoinduction, and osteoconduction.[20]
Osteogenesis is the ability of the graft to produce new bone, and this process is dependent on the presence of live bone cells in the graft. Osteogenic graft materials contain viable cells with the ability to form bone (osteoprogenitor cells) or the potential to differentiate into bone-forming cells (inducible osteogenic precursor cells). These cells, which participate in the early stages of the healing process to unite the graft with the host bone, must be protected during the grafting procedure to ensure viability. Osteogenesis is a property found only in fresh autogenous bone and in bone marrow cells, although the authors of radiolabeling studies of graft cells have shown that very few of these transplanted cells survive.[19]
Osteoconduction is the physical property of the graft to serve as a scaffold for viable bone healing. Osteoconduction allows for the ingrowth of neovasculature and the infiltration of osteogenic precursor cells into the graft site. Osteoconductive properties are found in cancellous autografts and allografts, demineralized bone matrix, hydroxyapatite, collagen, and calcium phosphate.[19]
Osteoinduction is the ability of graft material to induce stem cells to differentiate into mature bone cells. This process is typically associated with the presence of bone growth factors within the graft material or as a supplement to the bone graft. Bone morphogenic proteins and demineralized bone matrix are the principal osteoinductive materials. To a much lesser degree, autograft and allograft bone also have some osteoinductive properties.[19]
Neurosurg Focus. 2001;10(4) © 2001 American Association of Neurological Surgeons
Cite this: Principles of Bone Healing - Medscape - Apr 01, 2001.
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