Guinea pig and rabbit model for the histological evaluation of permanent percutaneous implants

The object of this study was to develop a small experimental animal model for a systematic study of the interfacial phenomena between percutaneous implants and skin. Plasma-sprayed and dense hydroxyapatite test implants were inserted into the tibia and dorsum of guinea pigs and into the tibia and on the cranium of rabbits. At preselected periods, the animals were killed and the implants with their surrounding tissues were processed histologically. The results revealed that the tibia and cranial implants had healed uneventfully. The epidermis showed no tendency to grow down into the dermis, but appeared to form a stable junction with the implant surface. Around the dorsal implants, the epidermis migrated downwards and most of these implants were lost 6 weeks after insertion. It was concluded that the guinea pig and the rabbit were a suitable model for studying the pathophysiology of percutaneous wound healing and that the implant location is an important factor for percutaneous implant success.