FEMORAL STEM ATTACHMENT FOR A MODULAR KNEE PROSTHESIS

A modular knee prosthesis includes a femoral component having a pair of laterally spaced apart condylar portions each having a superior, articulatio n surface and an inferior surface. A boss structure is disposed between and connects t he condylar portions. The boss structure has an inferior surface that extends generally horizontally in the transverse plane, and an opposed superior surface. The boss structure has an aperture having a selected configuration formed therein and which extends between the inferior and superior surfaces. The boss structure has formed on the superior surface thereof a positioning structure, e.g., a plurality of grooves, that define one or more positions, in the transverse plane, in which to seat a femoral stem assembly. A washer is mountable upon the superior surface of the boss structure and over a portion of the boss aperture. The washer includes at least one detent that cooperates with the positioning structure to secure the washer in one of the mounting positions.