Septic arthritis is an intensely painful infection in a joint. The joint can become infected with germs that travel through the bloodstream from another part of the body. Septic arthritis can also occur when a penetrating injury brings germs directly into the joint.

Infants and older adults are most likely to develop septic arthritis. The most common joints affected are the knees and hips. Septic arthritis can quickly and severely damage the cartilage and bone within the joint, thus prompt treatment is crucial.


Septic arthritis typically causes extreme discomfort and difficulty using the affected joint. The joint may be swollen, red and warm, and you might have a fever and pain.


Septic arthritis can be caused by bacterial, viral or fungal infections. Bacterial infection with Staphylococcus aureus (staph) is the most common cause.

Septic arthritis may develop when an infection elsewhere in the body, such as an upper respiratory tract infection or urinary tract infection, spreads through the bloodstream to a joint. Less commonly, a puncture wound, drug injection or surgery in or near a joint may give the germs a pathway into the joint space.

Risk Factors

Risk factors for septic arthritis include:

  • Existing joint problems.
  • Taking medications for rheumatoid arthritis.
  • Skin fragility.
  • Weak immune system.

Having a combination of risk factors usually puts the patient at a greater risk than having just one risk factor.


If treatment is delayed, septic arthritis can quickly lead to joint degeneration and permanent damage.


Preventive antibiotics application is possible if the subject is at high risk for septic arthritis; early treatment is essential to prevent long-lasting joint damage. If the person is otherwise healthy and would like to decrease the chances of developing septic arthritis, things you can do are:

  • Get regular exercise. A body full of strong, healthy bones, muscles, and joints isn't as prone to developing some kinds of arthritis.
  • Control the weight. Maintaining a weight that is appropriate for the height and bone structure can help reduce the risk of developing arthritis in load-bearing joints, such as the knees.

Skeletal infections can be extremely painful and can have long-term affects on the health.