Challenges to Creating Replacements That Work
Reducing Wear
 
  In order to design a replacement that will work well and last for a long time, it is necessary to understand how each joint functions, including:  
 
  • How the joint moves in its normal healthy state, including the range of motion found among different people.
  • The stresses and forces the replacement will have to withstand during use.
  • The normal distribution of the recipient's body weight and the mechanical forces generated by moving the joint, so that the replacement can be designed and placed to distribute them in the same way.
  • The normal pattern of wear in a healthy joint.
  • Why different types of implants eventually "wear out" or fail, and how they can be redesigned to last longer.

Some early implants did not reproduce the original joint's motion well.

Today's joint replacements are based on a much more complete understanding of how joints work. The science of biomechanics, which combines aspects of biology and engineering to study the mechanics of living things, has greatly increased our knowledge about the function of joints and our ability to create better replacements.

A type of biomechanical study that has helped improve the quality of knee and hip replacements.