Use of ITAP implants for prosthetic reconstruction of extra-oral craniofacial defects

Abstract

We report the outcomes of a single-stage, surface-mounted implant used as a bone-anchor for prosthetic reconstruction of complex facial defects. The implant used differs from other designs of osseointegrated bone-anchor because it was designed to be implanted in one-stage with the added intention of integrating with the adjacent soft-tissue. Our aim was to extend the principles underlying the intraosseous transcutaneous amputation prosthesis (ITAP) into the design of infection-free implants suitable for direct skeletal attachment of a prosthesis to the craniofacial skeleton. The implants were manufactured incorporating a porous flange structure coated with hydroxyapatite to encourage soft-tissue integration. These were inserted into the cranial facial skeleton at a number of different sites in 6 adult patients. A total of 16 implants were inserted using a one-stage procedure and implants were followed up for periods of 18 months - 7 years. One implant loosened at 3 months. This implant experienced multiple episodes of infection and was replaced with another ITAP implant 4 years later. The replacement is now stable and has never been infected at 18 months after insertion. One other patient experienced a few minor episodes of superficial infection (not requiring antibiotics) in the first year but no episodes thereafter. One patient died during follow-up (death unrelated to implant surgery). Patients were asked for their personal opinions using a structured questionnaire. All the patients were either very satisfied, or satisfied with their ITAP implants. Two patients reported problems with skin irritation under their prosthesis. All would be happy to undergo this type of surgery again. We conclude that a single-stage, surface-mounted implant designed to incorporate the principles of ITAP can be used to produce an effective bone-anchor for an external prosthesis in the reconstruction of complex craniofacial defects.