Design of a Graded Cellular Structure For an Acetabular Hip Replacement Component

This paper was presented at the Proceedings of the The Seventeenth Solid Freeform Fabrication Symposium Austin, TX, August 14-16, 2006.The state-of-the-art porous coatings become more and more popular in uncemented prostheses to make bone grow into implants for biological fixation. In this paper, graded cellular structures are proposed for uncemented prostheses to enhance stability on implant-bone interfaces. As an example study, the authors develop a new acetabular implant with gradient porosity for hip replacement. A gradient porous acetabular component with cellular structure could match the bone’s elasticity. Material is adaptively distributed from high porosity at the bone-implant interface to solid metal at the joint’s articulating surface. The new acetabular prosthesis would replace metal-on-polyethylene bearing with metal-on-metal bearing for less wear. The design problem of acetabular component is formulated and a requirement list is elaborated. A detailed design of the prosthesis with a graded cellular structure is presented. The design concept is validated with a comparison to the existing products according to the design requirements.National Science Foundation (Grants #DMI-0522382; DMI-0522382)