Biomechanically induced tissue reactions after Al2O3-ceramic hip joint replacement. Experimental and early clinical results.

A biomechanical concept of interface maturation around cement-free implanted alumina-ceramic hip endoprostheses in sheep is explained. Provided there is rigid primary stability of the implant within the bone bed, hard tissue formation along the support areas of the implant is mainly dependent on implant shape and main local stress direction. Three subsequent phases of interface maturation can be distinguished, finally resulting in firm fixation of the implant by mechanical interlocking of supporting bone and ceramic.