Original surface replacement total hip prosthesis with alumina ceramic prosthetic head without cement.

We have developed a surface replacement total hip prosthesis of H.D.P. socket to ceramic head type having a polycrystal alumina ceramic prosthetic head and without bone cement for fixation. The strength test was done on this hip prosthesis, and comparative studies were made between the metal prosthetic head and the ceramic prosthetic head, using calculation models prepared in consideration of friction and the prosthetic head's inside diameter. Besides, the cadaver femur was replaced by the prosthetic head, and the impact test and the fatigue test by means of repeated loading were done. As we could consequently confirm that it could be fully used for clinical practice, we have manufactured various instruments to be used for surgery, and we are now actually practicing it.