A Rat Tail Model for Osseointegration Studies and New Bone Formation Follow-up

Animal studies are necessary to precede clinical studies. Recently the rat tail model has been proposed by us as a model for studying bone regeneration with easily surgical approach, effective control of post-operative pain and a decrease of animal number. The present study aimed to widen the rat tail model indication to implant osseointegration. Special titanium implants were inserted through tail vertebrae. A good primary stability was observed three month after implant placement. X-ray microtomography (Micro-CT) and histology were used to visualize bone formation and to calculate bone implant contact. Micro-CT showed osseointegrated implants in caudal vertebra. This illustrates the possibility to obtain bone implant-contact by micro-CT measurements. The results suggest that the rat caudal vertebrae may serve as a good preclinical model for studying implant osseointegration with the possibility of multiple testing within the same experimental animal and the potential to decrease number of experimental animals.