Blade-like stem for a femoral head prosthesis

摘要

The stem of the femoral head prothesis has a distal zone of cylindrical cross-section and a proximal zone of rectangular cross section which extends from the distal zone. The sides of the stem in the proximal zone are plane with outstanding parallel ribs which can be driven into the spongy tissue of a femur bone. The ribs on the anterior side of the stem are of a lower height than the ribs on the posterior side. The outermost ribs on each side provide for a resilient four-point bearing on the hard cortical shell of the fem>r bone. A pair of trochanter wings are provided on the narrow lateral side to penetrate into the cortical shell of the femur bone in order to preclude rotation of the stem within the bone.