Optimising calcium phosphate cement formulations to widen clinical applications

The demand for reconstructive orthopaedic implants continues expanding at a reasonable pace as the incidence of fracture injuries and infectious diseases rises. There has been an increase in the clinical need for more effective synthetic bone graft materials due to the drawbacks of autogenous grafts. Since the 1980’s calcium phosphate cements (CPC’s) have attracted a great deal of interest due to their chemical similarities to natural bone; chemical, physical and mechanical characteristics have been investigated and manipulated to maximise osteoconductivity and osteointegration of these CPC’s since the start of their commercialisation. Here in this thesis, a series of investigation are complied to demonstrate novel and inventive approaches to expand the application of CPC’s: (1) limiting the liquid phase in the setting reaction of a brushite cement to produce monetite (dehydrated brushite) based cement, with increased solubility to overcome the problems faced by long term stability of hydroxyapatite (HA) cements; (2) manipulating the cement formulation to produce a cement that can set on a change in temperature, upon implantation, increasing handling time during surgeries; (3) incorporating therapeutic molecules to eliminate secondary surgeries following infectious diseases; (4) to enhance osteointegration of CPC’s by synchronising the degradation to natural bone formation. Results exhibit compressive strength appropriate for the application of cranioplasty; long term ageing studies demonstrates that the novel cement formulations do not hydrolyse to HA, eliminating the risk of catastrophic brittle failure that is commonly associated with CPC’s