The Impingement-free, Prosthesis-specific, and Anatomy-adjusted Combined Target Zone for Component Positioning in THA Depends on Design and Implantation Parameters of both Components

Background Lewinnek’s recommendation for orienting the cup in THA is criticized because it involves a static assessment of the safe zone and because it does not consider stem geometry. A revised concept of the safe zone should consider those factors, but to our knowledge, this has not been assessed. Questions/purposes (1) To determine the shape, size, and location of target zones for combined cup and stem orientation for a straight...