Immunohistochemical study of clinical skin-penetrating titanium implants for orthopaedic prostheses compared with implants in the craniofacial area.

The technique of using osseointegrated bone-anchored percutaneous titanium implants in the rehabilitation of patients with amputated limbs has recently been introduced at the Brånemark Osseointegration Centre in Göteborg. The new method is based on an implantation technique that is well-established for anchorage of bone-conductive hearing aids and craniofacial prostheses. The soft tissues around skin-penetrating titanium implants used to anchor orthopaedic prostheses were evaluated histochemically using quantitative analyses. The implants had been in clinical use for between 6 to 24 months. The number of inflammatory cells was higher in the area close to the interface than in the area distant from the skin-penetrating site, and higher than in the corresponding controls. The current data was also compared with corresponding data from tissue around skin-penetrating craniofacial implants. The number of inflammatory cells was lower in the orthopaedic samples than in the craniofacial specimens. We conclude that skin-penetration of orthopaedic implants is as safe as when titanium implants are used for craniofacial rehabilitation, which is a clinically well-established procedure.