Long term in vivo performance of low temperature 3D printed bioceramics in an equine model

Bone has great self-healing capacity, but above a certain critical size bone defects will not heal spontaneously, requiring intervention to achieve full healing. Amongst the synthetic calcium phosphate (CaP) bone replacement materials, brushite (CaHPO4·2H2O)-based materials are of particular interest, because of their degree of solubility and the related high potential to promote bone regeneration after dissolution. They can be produced tailor-made using modern 3D printing technology. While this type of implant has been widely tested in vitro, there is only limited in vivo data and less so in a relevant large animal model. In this study, the material properties of a 3D-printed brushite-based scaffold are characterized, after which the material is tested by in vivo orthotopic implantation in the equine tuber coxae for 6 months. The implantation procedure was easy to perform and was well tolerated by the animals that showed no detectable signs of discomfort. In vitro tests showed that compressive strength a...