Hip joint prosthesis with exchangeable joint head - has tenon on anchoring shaft fitting into shaped hollow section in head

摘要

The hip joint prosthesis has an exchangeable joint head (4) having a hollow section (8) for fixing into position. A tenon (12) is shaped to enter this hollow section (8). The tenon (12) is part of the anchoring shaft (10) of the anchoring piece (6) of metal. The congruent surfaces (14, 16) in the matching regions of the tenon (12) and hollow section (8) are sections of surfaces having guide curves of defined limits. The curves deviate from a perfect circular form. They can roughly form a triangular shape having curved sides and rounded corners. The tenon and hollow section can be of matching truncated conical shape.