An inflammation of a joint caused by bacterial invasion (but not the bacterium that causes gonorrhea).

Alternative Names

Bacterial arthritis; Septic arthritis

Causes, incidence, and risk factors

Septic arthritis develops when bacteria spread from a source of infection through the bloodstream to a joint or the joint is directly infected by traumatic penetration or surgical procedures. The onset of the symptoms is usually rapid with joint swelling , intense joint pain , and low-grade fever . Risk factors include a concurrent bacterial infection, chronic illness, diseases or medications that suppress the immune system, rheumatoid arthritis , intravenous drug abuse , artificial joint implants, recent joint trauma, or recent joint arthroscopy or surgery procedures. Septic arthritis may be seen at any age. In children, it occurs most often in those less than 3 years of age. The hip is a frequent site of infection in young infants. Septic arthritis is uncommon from age 3 to adolescence at which time the incidence of septic arthritis increases again (appearing as gonococcal arthritis in females with cervical gonorrhea ). Adult septic arthritis differs little from that in younger children with the exception of certain organisms not usually seen in the adult ( group B streptococcus and Haemophilus influenza ). Acute septic arthritis tends to be caused by organisms such as staphylococcus, streptococcus (pneumoniae) and group B streptococcus while chronic septic arthritis (which occurs less frequently) is caused by organisms such as Mycobacterium tuberculosis and Candida albicans. The knee and the hip are the most commonly infected joints.

Signs and tests

synovial fluid analysis

or

culture of joint fluid

blood culture

X-ray of affected joint

Treatment

The goal of treatment is to eliminate the infection with antibiotic therapy.

Antibiotic treatment is initiated as soon as the diagnosis is made, based on the best clinical judgment of the causative organism. Adjustments in antibiotics can be made when culture results showing the causative organism are available. The specific antibiotic used depends upon the sensitivity of the organism to the antibiotics. When synovial fluid accumulates rapidly in the joint as a result of the infection, frequent aspiration of the fluid by inserting a needle into the joint or surgery may be indicated. Severe cases may require surgery to drain the infected joint fluid. Rest, immobilization, elevation, and warm compresses may be used at the onset of treatment for pain relief measures. Performing exercises for the affected joint aids the recovery process.

Expectations (prognosis)

Recovery is good with prompt antibiotic treatment. If treatment is delayed, permanent joint damage may result.

Complications

joint degeneration

Calling your health care provider

Call for an appointment with your health care provider if symptoms of this disorder develop.

Prevention

Prophylactic (preventive) antibiotics may be helpful for high-risk people.