One of the biggest reasons joint replacements fail is due to implant loosening causing chronic pain and disability. Loosening from joint infection is referred to as septic failure. Loosening from other (noninfectious reasons) such as bone fracture, brittle bones that can’t hold the implant, or some other mechanical problem is aseptic (without infection).
Bacteria (sometimes referred to as “bugs”) and fungi can travel through the bloodstream. These pathogens can be carried by the blood to anywhere in the body including the joints causing infection.
This type of periprosthetic infection (in or around the joint) can develop anytime from early on (within the first six weeks of surgery) up to months or years later. Diagnosis can be a challenge. For example, this effect doesn’t show up on ordinary imaging studies such as X-rays. And it isn’t usually until the patient develops serious symptoms such as fever, nausea, and fatigue that there is even any awareness of the problem.
It isn’t always clear from the results of tests to diagnose periprosthetic joint infection that there is a problem. A suspected (but not confirmed) infection must be evaluated more carefully because if treatment is delayed or not given at all, the joint can (and often does) loosen. Sorting out loosening implants from septic (infectious) causes and aseptic (without infection) causes is important in planning the most appropriate treatment.
For septic joints, systemic antibiotics with or without surgical irrigation (washing out the joint to remove these pathogens and keep them from spreading) may be the first line of treatment. But sometimes nothing short of removing the implant works. All the more reason why early recognition of a developing infection and quick intervention are important (to save the joint if possible).
Mechanical problems such as loosening from bone fracture around the implant or fracture of the implant itself may also require surgery. The failed implant is removed and replaced if possible — or the cause of the implant failure is treated if it’s not caused directly by the implant.
Once your surgeon confirms what is going on for you, a plan of care based on the specific cause of the loosening (septic or aseptic) will be developed.