Development and in vitro validation of a simplified numerical model for the design of a biomimetic femoral stem.

Background: Dense and stiff metallic femoral stems implanted into femurs for total hip arthroplasties produce a stress shielding effect since they modify the original load sharing path in the bony structure. Consequently, in the long term, the strain adaptive nature of bones leads to bone resorption, implant loosening, and the need for arthroplasty revision. The design of new cementless femoral stems integrating open porous structures can reduce the global stiffness of the stems, allowing them a better match with that of bones and provide their firm fixation via bone ingrowth, and, thus reduce the risk of implantation failure.

Femoral stem incorporating a diamond cubic lattice structure: Design, manufacture and testing.

Background: The current total hip prostheses with dense femoral stems are considerably stiffer than the host bones, which leads to such long-term complications as aseptic loosening, and eventually, the need for a revision. Consequently, the lifetime of the implantation does not match the lifetime expectation of young patients.

Method: A femoral stem design featuring a porous structure is proposed to lower its stiffness and allow bone tissue ingrowth.