SEMIFINISHED PRODUCT FOR MANUFACTURING PROSTHESIS TO BE EMBEDDED WITH ACCURATE FIT, MANUFACTURE THEREFOR, MANUFACTURE FOR PROSTHESIS TO BE EMBEDDED IN BONE CAVITY AND COXA INNER PROSTHESIS

摘要

PROBLEM TO BE SOLVED: To make seating in a bone cavity secure so as to buffer the impact load by embedding a metal core in a mantle formed of cement for bone in such a manner that the outside dimension of the mantle is larger than the corresponding wall-to-wall distance in the bone cavity. SOLUTION: A semifinished product having a shaft part 2 and a head part 3 is formed of titanium or a titanium alloy. The shaft part 2 is smaller than a usual bone cavity where a coxa inner prosthesis is inserted, and formed in the shape of the shaft of the coxa inner prosthesis. The surface of the shaft 2 is coated with an adhesion assistant 4 to improve adhesion of cement for bone of the mantle 5 on the shaft 2. A collar 6 is disposed between the shaft 2 and the head 3 to form a surface for receiving the bone. An adhesive agent layer 4 is formed on the shaft part 2 and surrounded with the mantle 5 formed of cement for bone by injection molding method. Though the mantle 5 can be determined arbitrarily in respect to the thickness, it should be made large enough in order to meet the dimension of the bone cavity after working. Thus, the prosthesis can be manufactured accurately according to the cone cavity dimensions.