Final answer:
In joint replacement surgery, a damaged joint due to rheumatoid arthritis is typically replaced with an artificial prosthesis, not a natural or donor joint. These artificial joints are designed to reduce friction and improve durability, offering relief from chronic pain and improved mobility.
Step-by-step explanation:
A patient with rheumatoid arthritis has consented to joint replacement surgery. In such a procedure, known as arthroplasty, the damaged joint is replaced with an artificial prosthesis. These prosthetic joints are usually made from materials with very low friction coefficients, such as metals like stainless steel or titanium, and plastics like polyethylene, to mimic the function of a natural joint as closely as possible. Progress in the science of prosthesis design has vastly improved the quality, durability, and customization of these artificial joints. The devices used in hip replacements, for example, include a metal ball that fits into a plastic cup. This advanced medical technology can provide significant relief from chronic pain and enhance mobility after a period of healing and physical rehabilitation.