Demand for hip replacement surgery is rising with the increasing age of the human population. The effects of the cementless acetabular cup are not fully understood, and as such is the focus of the present research. The inserted cup being 2 mm larger in diameter than the reamed hip induces significant stresses upon the surrounding bone. The magnitude of the induced stresses within the hip impact the ingrowth of bone into the fixture. Therefore a complete understanding of the induced stresses from various implant designs will allow an analysis to be made to increase the useful part life preventing revision surgery. A full three dimensional finite element analysis is performed upon several different hip geometries obtained from CT scans analyzed using various commercially available software packages. The CT scans are segmented using Amira (see upper-left image), the solid model is then reamed using ProEngineer (see upper-right image), and the geometry is meshed and analyzed with the software package ABAQUS (see images below). The present study includes 5 different hips, each of which will be analyzed for the insertion of 5 different acetabular cup designs.

Finite Element Mesh Including the Acetabular Ream

Residual Stresses After Cup Insertion

• Zimmer, Inc.