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Septic arthritis
Make it clearer
Septic arthritis is inflammation of a joint caused by an infection, almost always by bacteria. It is an orthopedic emergency, meaning that time counts.
To understand why it happens, you have to look at the synovium, the membrane that lines the inside of the joint. It has a great many blood vessels and, unlike other tissues, it has no limiting basement membrane, the layer that elsewhere works as a filter. The joint is like a window with no screen: whatever the blood carries gets in. So if there is an infection elsewhere in the body, microorganisms can reach the joint hematogenously, that is, traveling through the blood. Once inside, they damage the joint cartilage, the smooth surface that lets the bones glide.
Typically it affects a single large joint, the hip or the knee, with pain that starts suddenly, fever, swelling and a clear resistance to moving it.
In brief
Septic arthritis is inflammation of a joint caused by an infection, almost always bacterial, and it is an orthopedic emergency.
The synovium is richly vascularized and has no limiting basement membrane, so microorganisms can reach it hematogenously from a systemic infection and damage the joint cartilage.
The joint is like a window with no screen: whatever the blood carries gets in.
It usually affects a single large joint, such as the hip or knee, with sudden pain, fever, swelling and resistance to moving it.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingSeptic Arthritis, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated