Osteointegration in Custom-made Porous Hydroxyapatite Cranial Implants: From Reconstructive Surgery to Regenerative Medicine

BACKGROUND: Custom-made porous hydroxyapatite (HA) implant (Fin-Ceramica Faenza S.p.A., Italy) is a biomimetic, osteoconductive material. Margin fusion at the bone-implant edge, cell proliferation within implant pores, and osteointegration in an animal model have already been described.

CASE DESCRIPTION: Radiological, microtomographical, and histological analyses were performed on two patients who underwent surgical explantation of cranial implants after postoperative complication. Primary devices explanted after 2 years showed areas of newly formed bone strictly osteointegrated with pores of the prosthesis. These prostheses showed a focal zone of resorption in correspondence of the newly formed bone, and no signs of inflammation or cytotoxicity were observed. A back-up prosthesis, explanted from the same patient after 6 months because of an infection, did not show presence of newly formed bone both on the surface and in the internal part of the prosthesis.

CONCLUSIONS: Custom-made porous HA implant is an osteoconductive material able to promote osteogenesis, osteointegrate with bone tissue, provide an effective cranial reconstruction, and restore functional features of the skull. However, complete bone healing is still a complex and long process.