X
Table of contents

Septic arthritis

Feel like sharing?

What is septic arthritis?

Septic arthritis is an infection in a joint that can lead to serious pain and permanent damage. It requires immediate medical treatment.

Also known as infectious arthritis, septic arthritis is most commonly caused by bacteria.

Causes

The organism that causes septic arthritis can reach the affected joint:

When the joint is infected, pus builds up, causing damage to the structures of the joint.

Risk factors

Factors that can increase the risk of developing septic arthritis include:

  • Conditions that cause joint damage, such as rheumatoid arthritis, lupus, gout or osteoarthritis;
  • Recent joint surgery;
  • Having a prosthetic joint;
  • An impaired immune system, which can be caused by other medical conditions (such as diabetes) or medications that suppress the immune system such as chemotherapy;
  • Conditions that increase the risk of skin wounds, such as psoriasis and eczema;
  • Alcoholism or injecting drugs, and;
  • Untreated gonorrhea.

Types

Nongonococcal septic arthritis

This is septic arthritis that is caused by organisms other than Neisseria gonorrhoeae. A wide range of organisms can be the cause, but Staphylococcus aureus is the most common.

It is more likely to occur in older people and young children. Knees and hips are the joints most likely to be affected.

Gonococcal septic arthritis

This form of septic arthritis is caused by Neisseria gonorrhoeae, the type of bacteria responsible for the sexually-transmitted disease gonorrhea.

It is most common in younger, sexually active people, particularly:

Initially, people with gonococcal septic arthritis tend to experience pain that shifts through the joints such as the knees, ankles, wrists and elbows. Following this:

Most people with gonococcal septic arthritis also develop lesions on the skin of their extremities, particularly the palms of the hands and soles of the feet. These lesions often feature a number of small pustules.

Signs and symptoms

Symptoms of septic arthritis include pain, heat and swelling in affected joints. The skin over the joint may be red and the pain can be severe. Often, people with septic arthritis also get chills and fever, but this is not always the case.

The knee is the joint most commonly affected, but septic arthritis can also occur in the shoulder, wrist, hip and ankle and, less commonly, in other joints.

Symptoms usually develop within hours. Usually only one joint is affected, but more than one joint can be involved.

Methods for diagnosis

Tests used to diagnose septic arthritis include:

X-rays are generally not useful in detecting septic arthritis, but may be recommended to identify other potential causes of pain in the joint. An MRI may be recommended in cases where it is difficult to assess a joint (such as with the hip).

Where gonococcal septic arthritis is suspected, tests to identify Neisseria gonorrhoeae infection in other parts of the body (such as the urethra, rectum, cervix and pharynx) may be recommended.

Types of treatment

A stay in hospital is usually required to treat septic arthritis.

Nongonococcal septic arthritis

Antibiotic treatment

High doses of antibiotics such as vancomyacin or ceftazidime are given intravenously. Treatment is usually started as soon as possible and may begin before the type of bacteria causing the infection is definitively identified.

The choice of antibiotic may depend on many factors. The antibiotic may later be changed to better target the infection once the bacteria is identified.

Once the infection has begun to improve, lower doses of antibiotics taken by mouth may be prescribed to ensure that infection clears completely from the joint.

Antifungal treatment

In the much-less common case of a fungus causing the infection, antifungal medications will be used to treat the infection.

Viral infections

Infections of joints caused by viruses generally resolve over time without treatment. Antibiotics do not help to treat viral infections.

Drainage of the joint

Pus is drained from the joint to reduce damage while the antibiotics are fighting the infection. This may need to be repeated multiple times. Depending on the joint affected, drainage may be done with a needle, an arthroscope or, particularly with hip joints, open surgery may be required.

Infection in an artificial joint

If the infection occurs in an artificial joint, the prostheses may need to be removed in order for the infection to be treated. They can usually be replaced once the infection has settled down.

Pain relief

Pain-relief medications such as non-steroidal anti-inflammatories (NSAIDs, including ibuprofen) can help to reduce symptoms such as pain, inflammation and fever.

For the first few days, the joint may be placed in a splint because any movement of the joint is often very painful. However, splinting is usually only recommended for a short time.

Physiotherapy

Physiotherapy is very important to preserve function in the affected joint. Initially, exercises that maintain the range of motion of the joint can help recovery. When the infection has subsided, more strenuous exercises to strengthen the muscles around the joint may be recommended.

Gonococcal septic arthritis

This form of arthritis usually responds quickly to antibiotics (such as azithromycin and ceftriaxone) given intravenously.

Potential complications

If septic arthritis is not treated promptly, serious and permanent damage can occur to the joint leading to:

Treatment with antibiotics can cause side effects including nausea, vomiting and allergic reactions.

Prognosis

Prognosis depends on the type of organism that has caused the infection and how promptly it is treated.

People with gonococcal septic arthritis usually make a full recovery. Damage to the joint with nongonococcal septic arthritis tends to be more severe.

Prevention

Practicing safe sex can help to prevent gonorrhea and gonococcal septic arthritis.

References

  1. Papadakis, M., McPhee, S.J., Rabow, M.W. (eds.) (2014) CURRENT Medical Diagnosis and Treatment 2014. McGraw-Hill Medical.
  2. “Acute Infectious Arthritis: Infections of Joints and Bones: Merck Manual Professional.” Accessed October 16 2014. link here
  3. “CURRENT Medical Diagnosis and Treatment 2014 (LANGE CURRENT Series): 9780071806336: Medicine & Health Science Books @ Amazon.com.” Accessed October 16 2014. link here
  4. “Joint Infection.” Accessed October 7 2014. link here
  5. “Septic Arthritis.” Accessed October 7 2014. link here
  6. “Septic Arthritis Definition - Diseases and Conditions - Mayo Clinic.” Accessed October 7 2014. link here
  7. “Septic Arthritis Symptoms | Health | Patient.co.uk.” Accessed October 7 2014. link here

10 Most frequently asked questions (FAQs)

What is septic arthritis?
Septic arthritis is an infection in a joint. It can lead to serious pain and permanent damage.
What are the symptoms of septic arthritis?
Symptoms of septic arthritis can include severe pain, redness and swelling in affected joints. Many people will also experience chills and fever.
What causes septic arthritis?
Septic arthritis is caused by infection of the joint, generally by bacteria, although it can be by other organisms such as mycobacteria or fungi. The bacteria may get into the joint because of injury or surgery at or near the joint, but can also travel from other parts of the body through the bloodstream.
How is septic arthritis diagnosed?
Septic arthritis is diagnosed by analysis of synovial fluid, withdrawn from the space within the joint by a needle. Blood tests may also be done to detect the presence of bacteria in the bloodstream.
How is septic arthritis treated?
The first treatment for septic arthritis is high doses of antibiotics delivered intravenously. A stay in hospital is usually necessary. In some cases, draining pus from the joint is necessary to help limit damage while the antibiotics are clearing the infection.
Can septic arthritis be cured?
The infection that causes septic arthritis can usually be treated with antibiotic treatment. However, damage to the joint may be permanent.
Will septic arthritis clear on its own?
Septic arthritis will not clear on its own. Treatment that begins as early as possible is most effective at limiting damage to the joint. Depending on the type of infection causing it, untreated septic arthritis can cause severe damage to a joint within hours to days.
Are there different types of septic arthritis?
Septic arthritis is divided into gonococcal septic arthritis, which tends to be less severe and related to the sexually-transmitted disease gonorrhea, and nongonococcal septic arthritis, which is caused by other organisms.
What is the outlook for septic arthritis?
Depending on the organism that causes septic arthritis and how promptly treatment is started, there may be full recovery with no damage to the joint, through to damage that is serious and permanent.
Is septic arthritis serious?
Septic arthritis can be a medical emergency and rapidly cause serious damage to affected joints. Treatment is more effective the sooner it starts.

Related topics

Gout

Gout is an acutely painful condition that usually affects the big toe. It occurs when uric acid crystals form in certain joints, leading to inflammation, pain and swelling. Medications and changes in behaviour can reduce the likelihood of future gout episodes.

Arthritis

Arthritis refers to inflammation of joints. This can lead to stiffness, swelling and pain and may be due to a joint condition, an infection or an autoimmune condition. Most arthritis is chronic, however adhering to treatment plans and some modification of activities can help maintain an active lifestyle.

Avascular necrosis (osteonecrosis)

Avascular necrosis describes the death of bone tissue that occurs when the blood supply to an area of bone is cut off. It causes severe damage to the bone and is also known as ischemic bone necrosis, aseptic necrosis, bone infarction and osteonecrosis.

Bursitis

Bursitis is swelling and irritation of your bursa. Bursa are small sacs filled with synovial fluid that help reduce the friction when tendons or ligaments rub against other structures, such as bones, muscles and skin.

About this article

Title: Septic arthritis

Author: Dr Idan Ben-Barak PhD, MSc, BSc (Med)

First Published: 14 Jul 2015

Last reviewed: 17 Jan 2022

Category: Information on Septic arthritis

Average rating: 5.0 out of 5 (1556 votes)

Processing your vote now...

Sorry your vote failed to process.

Rate this report below.

Feel like sharing?

X

Your privacy

We use cookies to improve our website and service. By continuing to browse this website you accept the use of cookies by us and our partners. If you require more information please read our privacy policy and terms and conditions before proceeding.