Septic arthritis

Septic arthritis is an infection in the synovial fluid or tissues of a joint, such as a hip or a knee. The condition is usually caused by bacteria that have entered the joint through a nearby open wound or have traveled through the bloodstream from an infection elsewhere in the body. For example, the bacteria that cause gonorrhoea may spread from the genital track through the bloodstream. The risk of developing septic arthritis is increased in people who have fitted with an artificial joint or who use intra-venous recreational drugs.


What are the symptoms?

The symptoms of septic arthritis usually appear suddenly and may include:

- Fever.
- Swelling, tenderness, redness and warmth around the affected joint.
- Severe pain and restricted movement of the affected joint.

If pus builds up in an infected area, the joint may be damaged permanently. If you develop the above symptoms, consult your doctor immediately.

What may be done?

Your doctor may arrange for you to have a sample of fluid taken from the affected joint. The fluid is analysed to look for evidence of infection and to try to establish its cause.

Septic arthritis caused by bacteria is initially treated with intravenous antibiotics for at least 4 weeks. Your doctor may then prescribe oral antibiotics for several weeks or months.

To help to relieve pain and inflammation, pus may be drained from the infected joint several times. Your doctor may also prescribe a nonsteroidal anti-inflammatory drug. You should rest the joint until the inflammation has completely subsided.

Gentle movement is allowed and is important later on to prevent the joint becoming stiffened by shrinkage (sự co rút) of the surrounding tissues. If the infected joint is an artificial joint, it may need to be replaced surgically with a new artificial joint to allow the infection clear up.