Biocompatibility testing of new polymers in a moving implant bed.

Total reconstruction of the auricle requires a skilful surgical technique and an appropriate material for the shape-supporting frame. Up to now, there is no such material apart from autologous rib cartilage. The combination of chronic microtraumatisation of adjacent tissue caused by the mobility of an implant bed such as the auricle and the foreign-body reaction to currently available artificial polymers frequently results in extrusion. In our animal model (rats), polymers of different elasticity were implanted in a moving implant bed to analyse differences in foreign-body reaction related to implant elasticity. The results were significantly better for a rather stiff control material (porous polyethylene). A contributing factor may be better fixation of the implant material by tissue ingrowth into its micropores.