During an autograft procedure, tissue is harvested from the patient’s iliac crest, or possibly the distal femur or proximal tibia, and placed at the injury site. An allograft procedure usually uses donated cadaveric tissue. A grafting procedure using a bone graft substitute replaces human tissue with a synthetic or metal material. For the purposes of this report, metal replacement materials and bone cement will be excluded, as they are not considered biomaterials.
Material transplanted (or implanted) during a grafting procedure provides a scaffold where the body can generate new bone tissue through osteogenesis, thereby repairing the skeletal system. The three elements involved in osteogenesis are osteoconduction, osteogenicity and osteoinduction. Osteoconduction refers to the scaffolding that is needed to support new bone growth. Osteogenicity is the property of being able to form new bone tissue. Osteoinduction is the stimulation of the body to produce new bone tissue, usually by means of growth factors such as bone morphogenetic proteins (BMPs). Bone grafting is largely performed in dental procedures to replace missing teeth; within orthopedics, spinal fusion is the main driver of bone graft and bone graft substitute use. Indirect competition for the bone graft substitute market mainly comes from BMPs. The motion preservation device market, which aims to stabilize the spine without vertebral fusion, also competes with the bone graft substitute market.