Contact stress at articular surfaces in total joint replacements. Part I: experimental methods

It is now widely accepted that both the design and the operating conditions at articular surfaces in total joint replacements influence the magnitude of the contact stress at those surfaces. In turn, such stress plays a pivotal role in the clinical performance of the prosthesis. Hence, a plethora of methods have been used by many workers not only to determine or estimate this stress but also to identify the main influencing factors. This literature is critically reviewed in the present study, which is in two parts. In this first part, the focus is on experimental methods. Two main recommendations emerge from this review. First, the pressure-sensitive film should be used. Second, more work is needed in many areas, an example of which is the effect of the method of sterilization of tibial inserts on the contact stress at the tibiofemoral interface in knee implants.