Challenges to Create Replacements That Work
Getting It To Stay In Place
The method of bonding an implant to existing bone must:
  • Be able to withstand all the stresses and strains of daily use
  • Attach the replacement so that the forces exerted on the bone during use are distributed and not concentrated all in one spot (which might cause a fracture)
  • Ensure that blood flow to all parts of the bone is maintained. If blood flow is stopped, then that part of the bone will die and therefore break more easily.
  • Be made from materials that don�t deteriorate or release toxins when put inside the human body
  • Be made from materials that the body doesn�t try to reject

Doctors who pioneered joint replacements in the 1800s experimented with many different substances as �glues�.

Today�s replacements rely on one of two different techniques to bond them
to the bone.