Metal foam - biocement composites: Mechanical and biological properties and perspectives for bone implant design

Combination of open celled metal foams with high strength mineral bone cements opens new opportunities for design of bone implants. The tested metal/mineral composites provided not only very high initial compression strengths but furthermore a suitable mechanical stability over a broad range of deformation. Excellent biocompatibility of the investigated composites was prevalently caused by the mineral matrix. Filling with resorbable bone cement completely protected cultured bone cells from detrimental effects of corrosion products of iron metal matrices. Similarly, cytotoxic effects of corroding iron could be completely avoided by coating the iron foams with a brushite layer. The authors conclude that development of metal foam/biocement composites for application as bone implant materials deserves further efforts and especially testing in implantation studies that are predictive for performance in clinical use. In the long run bioactivation and control over corrosion may enable people to apply biocorrodable metals for implants with temporary function.