JOINT INFECTION OVERVIEW
A bacterial infection of a joint can cause a severe and potentially destructive form of arthritis, often referred to as septic arthritis. Bacterial joint infections can be caused by a number of different organisms and can occur in both natural and artificial joints (eg, after a knee replacement).
The most common type of joint infection is caused by N. gonorrhoeae, the sexually transmitted bacteria that cause gonorrhea; this is called a gonococcal joint infection. Joint infection with other types of bacteria is called nongonococcal bacterial (septic) arthritis. Infection of an artificial joint is known as prosthetic joint infection.
GONOCOCCAL JOINT INFECTION
Gonococcal joint infection symptoms — A person who becomes infected with gonorrhea but does not receive early treatment can develop joint pain, especially in the wrist, fingers, ankles, and toes. (See "Patient information: Gonorrhea (Beyond the Basics)".) This is called disseminated gonococcal infection, or DGI.
Symptoms can also include fever (temperature >100.4ºF or 38ºC), chills, and feeling ill. A skin rash can develop and may be mild (picture 1).
In other people, the knees, wrists, and/or ankles become painful and swollen due to collections of pus inside the joint; this is called purulent arthritis. More than one joint may be affected at the same time.
Gonococcal joint infection diagnosis — Your healthcare provider may use a syringe and needle to remove fluid from the joint to analyze it for signs of infection and bacteria. Blood tests and a test for gonorrhea are also usually recommended.
Gonococcal joint infection treatment — Treatment of gonococcal joint infections generally requires intravenous (IV) or intramuscular (IM) antibiotics. Oral antibiotics may be used in selected situations. The duration of treatment depends upon the severity of the infection and varies from three days to two weeks.
BACTERIAL (NONGONOCOCCAL) ARTHRITIS
Nongonococcal arthritis is an infection of a joint caused by bacteria other than N. gonorrhoeae (the bacteria that causes gonorrhea). (See "Septic arthritis in adults".)
Nongonococcal bacterial arthritis, also called septic arthritis, is a potentially dangerous form of arthritis that can destroy a joint if not treated promptly.
Bacterial arthritis symptoms — Symptoms of nongonococcal arthritis usually include sudden pain and swelling in one or more joints. A fever may or may not be present.
Bacterial arthritis diagnosis — A healthcare provider may use a needle and syringe to withdraw fluid from the joint. The fluid will be analyzed in a laboratory for bacteria and white blood cells. In some cases, this procedure will be done in the operating room.
Bacterial arthritis treatment — Treatment of bacterial arthritis includes antibiotics, drainage of the joint fluid, and physical therapy to maintain joint motion.
In most cases, antibiotics are given into a vein initially and then by mouth. Intravenous therapy is usually started in a healthcare provider's office or hospital. Treatment can be continued at home and monitored by a visiting or home health nurse. During home IV therapy, it is important to monitor yourself for signs of infection or inflammation at the site of the IV line (pain, redness, and swelling) and signs of a blood clot in the vein (pain and swelling in the arm or armpit). Drainage of the joint fluid may require repeated needle aspiration or, for some deep joints (eg, hip, shoulder), surgical placement of a drainage tube.
ARTIFICIAL JOINT INFECTION
People who have artificial joints are at risk of developing a joint infection. Approximately 0.5 to 1 percent of people with replacement joints will develop such an infection. Infections can occur early in the course of recovery from joint replacement surgery (within the first two months) or much later. (See "Patient information: Total knee replacement (arthroplasty) (Beyond the Basics)" and "Patient information: Total hip replacement (arthroplasty) (Beyond the Basics)".)
Unfortunately, artificial joint infections are hard to treat. This is due, at least in part, to the development of a structure called a biofilm within the joint. A biofilm develops when bacteria adhere to the solid surface of the artificial joint. The biofilm can act as a kind of shield to some of the bacteria, making it difficult for the bacteria to be found and destroyed by the body's defenses or by antibiotic medications.
Artificial joint infection symptoms — People who develop infections immediately after joint replacement surgery typically have pain, redness, and swelling at the joint or drainage from the wound. Those who develop infections later usually notice a gradual onset of joint pain, often without fever or other obvious signs of joint infection.
Artificial joint infection diagnosis — Artificial joint infections can be difficult to diagnose because the pain is similar to that of other complications of joint replacement surgery. Analysis of the joint fluid is helpful to rule out infection.
Artificial joint infection treatment — As noted above, treatment of artificial joint infections is difficult. Treatment usually includes a long course of intravenous (IV) antibiotics and surgery to remove infected tissue. In many cases, the artificial joint must be removed, at least temporarily.
After a period of antibiotic treatment and once the infection is controlled, a new prosthesis may be placed. However, in some cases, it is not possible to replace the prosthetic joint, and surgery to fuse the bones is recommended instead. (See "Treatment of prosthetic joint infections".)
WHERE TO GET MORE INFORMATION
Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient information: Osteoarthritis (The Basics)
Patient information: Hip replacement (The Basics)
Patient information: Knee replacement (The Basics)
Patient information: Ganglion cyst (The Basics)
Patient information: Septic arthritis (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient information: Gonorrhea (Beyond the Basics)
Patient information: Total knee replacement (arthroplasty) (Beyond the Basics)
Patient information: Total hip replacement (arthroplasty) (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Disseminated gonococcal infection
Evaluation of the adult with monoarticular pain
Joint aspiration or injection in adults: Complications
Clinical manifestations and diagnosis of prosthetic joint infections
Pseudomonas aeruginosa skin, soft tissue, and bone infections
Septic arthritis in adults
Synovial fluid analysis and the diagnosis of septic arthritis
Treatment of prosthetic joint infections
The following organizations also provide reliable health information.