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What Is Septic Arthritis?

Septic arthritis (or infectious arthritis) is a bacterial infection inside a joint. Joints are usually germfree (sterile). When bacteria get into a joint, they cause inflammation (swelling, redness) and pain. Infection usually affects only one joint at a time: knee, hip, wrist, shoulder, elbow, or ankle.

Anyone can have a joint infection, but it’s most common in children younger than 3 and adults older than 80.

Untreated septic arthritis can damage and destroy the joint and lead to joint replacement surgery.

What Causes Septic Arthritis?

Usual causes are abnormal changes in a joint from other forms of arthritis, a poorly working immune (infection-fighting) system, and an artificial joint (joint replacement). The immune system problem may be caused by medicines and other conditions, such as diabetes, kidney disease, or cancer.

What Are the Symptoms of Septic Arthritis?

Infected joints swell quickly and are very painful and hard to bend. High temperature, chills, shakes, muscle aches, and fatigue occur. Depending on the joint, people may be unable to walk or use their arms.

How Is Septic Arthritis Diagnosed?

The health care provider may suspect a joint infection on the basis of the medical history and physical examination. The doctor will diagnose a joint infection by removing fluid from the joint with a needle and testing it in the laboratory for evidence of infection.

Magnetic resonance imaging (MRI), nuclear scans and computed tomography (CT) are also commonly used when your health care provider suspects an infection in a joint.

How Is Septic Arthritis Treated?

Three stages of therapy are needed: antibiotics, joint drainage, and restoring normal motion to the joint.

Antibiotics are usually given through a vein for the first 2 weeks and then by mouth for 2 to 4 weeks or more.

Joint fluid should generally be drained to help resolve the infection. Most joints can be drained by sticking a needle into the joint and taking fluid out. This procedure is called arthrocentesis. Other joints are harder to drain this way and insteadneed drainage by an operation.

After the first few days of treatment, people with joint infections should start therapy to restore normal joint motion. Physical therapists help with restoring normal movement. Therapy should continue until after the pain leaves and the joint works normally.

DOs and DON’Ts in Managing Septic Arthritis:

  • DO take your medicines as prescribed.
  • DO ask your health care provider which over-the-counter drugs you may take with your prescription medicines.
  • DO exercises to maintain joint motion and preserve strength.
  • DO call your health care provider if you have drug side effects or if medicines and treatments don’t help the pain.
  • DO call your health care provider if you have new fever, chills, and worsening pain or swelling
  • DO call your health care provider if you need a referral for physical or occupational therapy.
  • DON’T wait to see whether medicine side effects will go away.
  • DON’T continue an exercise program that causes pain. If you have pain after exercise, the exercise program usually needs to be modified specifically for you.

Contact the following sources:

  • Arthritis Foundation
    Tel: (800) 283-7800
  • Centers for Disease Control and Prevention
    Tel: (800) 311-3435
  • Infectious Disease Society of America
    Tel: (703) 299-0200

Copyright © 2016 by Saunders, an imprint of Elsevier, Inc.

Ferri’s Netter Patient Advisor