Joint Infection 

Septic arthritis is an infection of the synovial fluid in a joint or the joint tissues. This often painful condition occurs more often in children, though it can also affect older adults. Individuals who have undergone joint replacement surgery are also at risk of developing a joint infection.  

Causes of Joint Infections 

Joint infections are usually a result of germs or an infection that develops in another part of the body, then enters the bloodstream and travels to a joint. They can also be caused by a penetrating wound, such as an animal bite, a direct joint injury or joint surgery.  

Some of the bacteria, viruses and fungi that can cause a joint infection include: 

• Staphylococcus aureus, which often causes skin infections and can enter the body through an open fracture, an infected wound or a laceration or along with a foreign object that enters the body 
• Haemophilus influenzae, which can be found in the throat 
• Streptococci, which can lead to a variety of diseases 
• Gram negative bacilli, a group that includes E. coli 
• Gonococci, which cause gonorrhea 
• Viruses, including HIV 

Symptoms of a Joint Infection 

Joint infections are most commonly found in knees, hips, elbows, wrists, shoulders and fingers.  

Symptoms can vary, but often include: 

• Fever and chills 
• Pain when the joint moves 
• Joint swelling 
• Progressive joint stiffness 
• Skin redness 

In an artificial joint, symptoms of infection can develop well after joint replacement surgery and can include minor pain and swelling or loosening of the joint 

Diagnosis of a Joint Infection 

There are several options for diagnosing joint infection: 

• An X-ray to look for irregularities 
• Blood tests to look for bacteria 
• The removal of a sample of joint fluid to check for white blood cells or bacteria 
• Phlegm, spinal fluid or urine tests to identify the source of infection 

Treatments for a Joint Infection 

Treatment will depend on the patient’s symptoms, age and health as well as the type of germ that is causing the infection.  

Some treatment options include: 

• Antibiotics 
• Antifungal medicines 
• Fluid drainage 
• Medicines for pain and fever 
• Physical therapy 

Tampa General Hospital offers treatment for a complete range of orthopaedic conditions, including joint infections.