Fat in bone xenografts: importance of the purification procedures on cleanliness, wettability and biocompatibility

Xenografting is a promising alternative to allografts and autografts. The remaining lipids in bone are known to influence the biocompatibility. A comparative study of wettability was done on standardized blocks of two biomaterials. A highly purified and defatted bovine bone graft (T650) was found to retain more water (2.06 g/block) than a less defatted biomaterial (T360, 0.3 g/block). Wettability, observed in the laboratory, may reflect an important in vivo property: the rapidity for extracellular fluids and blood cells to invade the graft and carry bone forming cells. When implanted in rabbit cancellous bone, T650 appears to be osteoconductive in a manner that allows trabecular architecture to be restored within 6 months.