Septic arthritis is a serious infection of the joints caused by bacteria. The tissue of the joint reacts to the infection and fights the bacteria by filling the joint with pus and inflammation. This action can increase pressure in the joint, affect blood flow, and damage the joint structures, bone, and surrounding cartilage.
Septic arthritis develops when bacteria attaches to tissue in the joint and begins to spread. The infection may be started by bacteria:
Septic arthritis can occur at any age, but it generally affects older adults and children aged 3 years old and younger.
Factors that may increase your chance of developing septic arthritis include:
In infants, the hip is a frequent site of infection. In toddlers, it is the shoulders, knees, and hips. In adults, it most commonly affects weight-bearing joints, such as the knees.
Symptoms may include:
You will be asked about you or your child’s symptoms and medical history. A physical exam will be done. Your doctor may refer you to a specialist.
Bodily fluids may need to be tested. 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 medication to kill the bacteria. The specific medications 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.
National Institute of Arthritis and Musculoskeletal and Skin Diseases
The Arthritis Society
Ernst AA, Weiss SJ, Tracy LA, Weiss NR. 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, Holroyd-Leduc JM. Acute monoarthritis: what is the cause of my patient's painful swollen joint? CMAJ. 2009;180(1):59-65.
Septic arthritis in adults. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T116123/Septic-arthritis. Updated May 30, 2017. Accessed January 11, 2018.
Septic arthritis in children. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T116123/Septic-arthritis. Updated December 5, 2017. Accessed January 11, 2018.
Septic arthritis. Patient UK website. Available at http://patient.info/health/septic-arthritis-leaflet. Updated August 30, 2013. Accessed June 29, 2015.
Last reviewed January 2018 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.