Shaft for hip joint prosthesis

In a femur component of a hip joint prosthesis consisting essentially of a straight shaft member defining a longitudinal axis, having a distal end, a proximal end, an anterior side, a posterior side, a medial side and a lateral side, said shaft member widening conically from said distal to said proximal end and from said medial to said lateral side, the improvement comprising said shaft member having in a proximal portion a plurality of distinct blades, having recesses therebetween wherein said blades and resecces are disposed substantially parallel to said longitudinal axis, each said blade having a broad surface extending a distance perpendicularly to the anterior posterior plane of said shaft and wherein said distance and depth of each of said blade and recess increases in a direction from said medial to said lateral side to yield a generally conical configuration;

• and said recesses between said blades having a depth which gradually decreases in a direction from said lateral to said medial side.