Why do knee replacements fail ?
Wear & tear in the artificial knee due to long term use.
There is a small plastic insert in between the two metal components of a knee replacement much like a small plastic washer to prevent metal rubbing directly on metal.
This plastic wears out during the course of time and the small bits of plastic provoke an inflammatory response damaging bone. The X-ray you see here shows bone destruction causing the knee replacement to “tilt” and become loose & painful.
Problems with “alignment”
If the alignment of the knee is not good it wears out/ causes pain sooner
Loosening
May be without infection or very rarely due to infection
Infection
Pain in the knee cap/ Anterior knee pain due to problems with “tracking” of the knee cap or “over stuffing” of the joint under the knee cap.
Problems with Instability of the knee replacement
The knee ligaments may have failed & therefore the artificial knee is unstable & painful.
Loose to a revision knee replacement or a redo