Ceramic bone grafts

Another important trend in the future will be the improvement in the biological properties of bone substitutes, the aim being to transform a bone defect into new mature bone as fast as possible. This implies that the focus will be set on resorbable materials that possess an open-porous structure allowing cells to invade the structure. Another potential focus could be set on osteoinductive ceramics. A number of authors have indeed observed that ceramic bone graft substitutes implanted under the skin or in muscles are filled or coated with bone over time. However, despite very intensive research, there is only a poor understanding of the mechanisms leading to osteoinduction, and as a result, it is not possible at the moment to design an osteoinductive ceramic. 

A last trend is to add minute amounts of foreign ions into ceramic bone graft substitutes to improve their biological behaviour. Most efforts have been set on Si, but other ions have been looked at such as Mg, Na, Sr, or Even... 

Difficulties with the clinical applicability of preformed ceramic blocks and granules have led to the development of injectable ceramic bone graft substitutes. In the early eighties, Brown and Chow were... 

S J. Kalita, et al., Porous calcium aluminate ceramics for bone-graft applications. J. Mater Res. 17(12), 3042-3049 (2002). 

Coral. Coral is used as harvested or after processing in the manufacture of bone grafts. It is a natural porous ceramic and can be converted to porous HA (see Section 35.7). Surgeons in the United States perform -500,000 bone grafts each year. 

A few million patients every year need a bone graft or bone graft substitute to repair a bone defect resulting from an injury or a disease. A large number of bone graft substitutes can be used unprocessed or processed allogenic bone, animal-derived bone substitutes and synthetic bone substitutes, mostly ceramics. ... 

Even though the first studies dealing with ceramic bone substitutes are more than 100 years old, it was only in the 1970s that research soared." In the early days, studies were focused mainly on porous blocks and granules." However, the discovery of calcium phosphate cements (CPC) in 1982-1983 opened up a new era in which the handling properties of bone graft substitute became of paramount importance. 

Designing ceramics for injectable bone graft substitutes 29... 

Yuan H, Fernandes H, Habibovic P, de Boer J, Barradas AM, de Ruiter A, et al. Osteoinductive ceramics as a synthetic alternative to autologous bone grafting. P Natl Acad Sci USA 2010 107 13614-9. 

To date, glass-ceramics have been used clinically for only limited applications. These include material for filling bony defects along the lines of a bone graft (Pavek et al., 1994), reconstruction of the ossicular bones (Hughes, 1987), spine reconstruction (Yamamuro and Shimizu, 1994), and dental reconstruction (Kudo et al., 1990 Yukna et al., 2001). 

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