(Bacterial Arthritis; Infectious Arthritis; Pyogenic Arthritis)
by Sid Kirchheimer
Septic arthritis is a serious infection of the joints caused by bacteria. This infection causes the joint to be filled with pus cells. These pus cells release substances directed against the bacteria. However, this action can damage the joint structures, bone, and surrounding cartilage.
Septic arthritis develops when bacteria spreads from the source of infection through the bloodstream to a joint. It can result from:
Septic arthritis can also be caused from injury or trauma. It can result from:
Septic arthritis can strike at any age. However, it occurs most often in children aged three and younger. In infants, the hip is a frequent site of infection. In toddlers, it is the shoulders, knees, and hips. In children, the most common bacterial causes are:
Septic arthritis rarely occurs from early childhood through adolescence. After that, it occurs more often. In adults, it most commonly affects weight-bearing joints, such as the knees. In adults, the most common causes are:
Risk Factors TOP
Factors that may increase your chance of developing septic arthritis include:
Symptoms may include:
Your doctor will ask about you or your child’s symptoms and medical history. A physical exam will be done. Your doctor may refer you to a specialist.
Your doctor may need to test your bodily fluids. This can be done with:
Images may be taken of your bodily structures. This can be done with:
Antibiotic therapy is started as soon as a diagnosis is made. In the beginning, antibiotics are given by IV. This is to ensure that the infected joint receives medicine to kill the bacteria. The specific medicines used depend on the type of bacteria that is causing the infection. The remaining course of antibiotics may be given by mouth.
Fluid may be removed from the joint to reduce the likelihood of joint damage. This may be done either by placing a needle in the joint or through surgery.
Rest, preventing the joint from moving, and warm compresses may be used to manage pain. Physical therapy or exercises may also speed recovery.
If you are diagnosed with septic arthritis, follow your doctor's instructions.
To help reduce your chance of getting septic arthritis, get prompt treatment of infections that could lead to septic arthritis.
The Arthritis Foundation
National Institute of Arthritis and Musculoskeletal and Skin Disease
Arthritis Society of Canada
Ernst AA, Weiss SJ, et al. Usefulness of CRP and ESR in predicting septic joints. South Med J. 2010;103(6):522-526.
Howard A, Wilson M. Septic arthritis in children. BMJ. 2010;341:c4407.
Ma L, Cranney A, et al. Acute monoarthritis: what is the cause of my patient's painful swollen joint? CMAJ. 2009;180(1):59-65.
Septic arthritis. EBSCO DynaMed website. Available at: https://dynamed.ebscohost.com/about/about-us. Updated April 11, 2013. Accessed August 6, 2013.
Septic arthritis. Patient UK website. Available at
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Updated April 28, 2010. Accessed August 6, 2013.
Last reviewed August 2013 by Michael Woods, MD
Last Updated: 5/11/2013