JOINT MOTION AND SURFACE-CONTACT AREA RELATED TO COMPONENT POSITION IN TOTAL HIP-ARTHROPLASTY

A three-dimensional computer model of a total hip replacement was used to examine the relationship between the position of the components, t he range of motion and the prosthetic joint contact area. Horizontal a cetabular positions with small amounts of acetabular and femoral antev ersion provide the largest contact areas, but result in limited joint movement. These data will allow surgeons to select implant positions t hat will provide the largest possible joint contact area for a given j oint range of motion although these are conflicting goals, In some com ponent positions a truncated spherical prosthetic head resulted in sma ller contact areas than a completely spherical head.