Septic arthritis is the medical term for a joint infection. Although many infectious organisms can cause a joint infection, the term "septic" is generally reserved for bacterial causes.

The two most common bacteria to cause septic arthritis are staphylococci (a common skin organism) and gonococci (the bacteria that cause gonorrhea). Many other organisms can cause septic arthritis, including Streptococcus species and the Lyme bacterium.

Septic arthritis usually develops as a complication of a blood stream infection or trauma, including surgery. Getting septic arthritis after arthroscopic knee surgery was in the news recently. Tom Brady, quarterback of the New England Patriots football team, developed this problem after surgery for torn ligaments.

Doctors treat septic arthritis with antibiotics. They also drain the joint with a needle or surgery. Surgery may be needed when needle drainage isn’t enough to get the job done or when the infection is not clearing up despite antibiotic treatment.

Septic arthritis is a curable condition, especially when doctors find it and treat it soon after symptoms appear. When the diagnosis is delayed, however, complications may follow. These can include joint damage, bone infection or the spread of infection elsewhere in the body.