What is septic arthritis?

Septic arthritis is an infection in a joint. The infection can come from bacteria, fungus, or a virus. This occurs when an infection from another part of the body, such as pneumonia or a skin or urinary tract infection, travels through the bloodstream to the joint. It may also spread to the joint from an infection in nearby soft tissue, or it can follow a surgery or injury. The joint is often warm, swollen, and tender.

Early treatment can prevent permanent damage to the joint. Treatment includes antibiotics and draining the joint to remove the infection. Depending on which part of your body is infected, your doctor may drain the joint with a needle or you may need surgery to drain the joint.

When you have septic arthritis, the infected joint is often warm, red, and swollen. You will likely have a lot of pain when you try to move the joint. Most people also have a fever.

Treatment often starts with antibiotics. This may be done in the hospital through a needle in a vein (I.V.). Your doctor may also drain the joint to remove infection. You may get a splint on your joint to protect it and prevent pain. Later, your doctor may also suggest physical therapy and medicines.

The main way your doctor will diagnose septic arthritis is by testing the fluid in the affected joint. The doctor removes the fluid. Then the fluid is tested in a lab. The test will help the doctor know if the fluid is infected. The test will also help find which germ is causing the infection.

Your doctor will do a physical exam. They will ask you about any past injuries or surgeries. The doctor will also ask about other health problems, such as arthritis or rheumatoid arthritis.

You may have tests to help check for infection. These may include blood or urine tests or a test of any infected skin. You may also have imaging to look for joint damage or extra fluid around the joint. This may include X-rays, ultrasound, MRI, or CT scans.

Rest the injured joint as much as you can. If possible, prop up the joint for the next 3 days. Follow your doctor's instructions on exercises for the joint. Take your antibiotics exactly as directed. And take the full course of antibiotics. Don't smoke. Smoking makes it harder for your body to fight infection.

In septic arthritis, the infection is most often caused by bacteria. A joint can become infected in several ways. Infection can travel to the joint through the blood from an infection somewhere else in the body. Examples are pneumonia, urinary tract infections, and skin infections. It can also happen after an injury or surgery.

Septic arthritis is an infection in a joint. The infection most often affects a knee, ankle, wrist, shoulder, or hip. The joint is often warm, swollen, and very painful. If it is not treated right away, it can quickly do serious damage to the joint.