Hydroxyapatite as a bone substitute

A bone substitute eliminates the need for autogenous and allogeneic bone grafting, along with the complications unique to each. Coralline hydroxyapatite is a synthetic bone void filler manufactured from marine coral, which has a natural trabecular structure similar to that of cancellous bone. While initial studies have been promising, the use of coralline hydroxyapatite may be limited in the foot and ankle owing to its inherent mechanical weakness and lack of biodegradation. In this retrospective study, 20 patients who received coralline hydroxyapatite implants were reviewed to determine associated complications and host reaction to the material. The results indicate that the material is biologically inert and safe to use as a small-defect filler in low-load applications. Long-term clinical trials are needed to determine the indications for this material in the foot and ankle.