In-vitro testing of bonesave, a ceramic bone graft substitute for use in impaction grafting

The incidence of revision total hip arthroplasty is increasing dramatically and the associated demand for allograft bone is likely to exceed the available supply. In addition allograft presents potential problems with regard to infection, antigenicity, availability, reproducibility and cost. It is therefore desirable to develop an alternative to allograft. This study investigated BoneSave, a porous tricalcium-phosphate/hydroxyapatite ceramic for use in impaction grafting of the femur at revision total hip arthroplasty. The findings of an in-vitro mechanical study comparing the initial stability of pure allograft, a volume mixture of 50% allograft and 50% BoneSave, and a volume mixture of 10% allograft and 90% BoneSave are reported. The BoneSave/allograft mixtures exhibit both much greater mechanical stability and reproducibility than the pure allograft (p<0.05) at all tested loads (200N-800N). At high peak loads the high volume (90% by volume) BoneSave mix also provided higher mechanical stability than the medium volume (50% BoneSave/50% allograft) mix (p<0.05). These results demonstrate that the tested ceramic provides adequate initial stability to be used as a substitute for allograft in impaction grafting of the femur.