Extraskeletal implantation of a porous hydroxyapatite ceramic.

Coralline replamineform hydroxyapatite implants were placed in canine subcutaneous tissues in an attempt to clarify whether the hydroxyapatite matrix acted as a passive matrix for osseous ingrowth when placed in some inherent bone induction capacity. The implants were well-tolerated and elicited no deleterious host response. Connective tissue rapidly infiltrated the pores, but no evidence of bone formation was noted in any of the specimens. It was concluded that this implant material does not act to induce bone formation.