What is prosthetic joint infection?

About 1-3% of people who receive an artificial joint replacement experience an infection around the joint – we call this a “prosthetic joint infection” or PJI for short.

PJI is defined as an infection caused by the presence of a microorganism (germ) growing in and on a joint prosthesis (artificial joint) and the adjacent tissue.  It is also referred to as a “periprosthetic infection”. This can happen in the weeks, months or years after the replacement surgery. A PJI is quite debilitating and can cause pain, swelling, and stiffness of the joint.

These infections are harder to cure than most infections because the artificial joint is a foreign body with no blood supply of its own. This means that antibiotics and the immune system, which is designed to fight and kill germs in the body, can’t always kill the germs causing the infection.

These germs have an ability to stick onto and hide on the plastic, metal or the bone around the artificial joint.  They can form a thin layer or coating which is called a “biofilm”. This biofilm acts as a place for the germs to hide and continue to grow.  Making it hard to both treat and completely kill."