New Injectable Composites for Bone Replacementd

A new class of biomaterials is emerging: injectable composites for bone replacement. They include injectable ceramics and injectable calcium phosphate hydraulic cements, such as calcium deficient hydroxyapatite cements, dahllite cements, or brushite cements. Their main advantages are their biocompatibility, resorbability, osteoconductivity, and injectability, which allows a delivery with a syringe and a needle through a percutaneous approach. Furthermore, they can be used for the controlled delivery of antibiotics or bone morphogenetic proteins. Their mechanical properties remain nonsatisfactory as compared to orthopedic cement [polymethylmetacrylate (PMMA)], but these materials still have a great potential for improvement. There is a large field of potential clinical applications for these composites, especially in implantology, bone surgery, traumatology, interventional radiology, and rheumatology. However, the biological properties of a limited number of these compounds have been studied so far and further biological evaluations, as well as rigorous clinical studies, remain to be made.