What is a bone infection?
A bone infection, medically known as osteomyelitis, occurs when bacteria or other microorganisms enter the bone tissue. The infection causes inflammation that can impair blood flow in the bone, which in turn can damage the skeleton if not treated in time. Bone infections can occur throughout the body but are most common in:
- Legs and feet (especially in people with diabetes)
- Vertebrae (spondylitis)
- Long bones such as the femur or upper arm (most common in children)
Common symptoms of bone infection
Symptoms of a bone infection can come on gradually or develop quickly depending on whether the infection is acute or chronic. Here are common symptoms:
Local symptoms at the affected area
- Dull and deep pain in the bone that often worsens with movement
- Swelling, redness, and increased heat over the infected site
- Tenderness when pressing on the bone
- Sometimes non-healing or draining wounds (in chronic infection)
General symptoms (systemic)
- Fever and chills
- A sense of illness and fatigue
- Limited mobility in the nearby joint
Why do you get a bone infection?
A bone infection is usually caused by bacteria (commonly Staphylococcus aureus) reaching the bone via three different routes:
- Bloodstream: Bacteria from an infection elsewhere in the body (e.g., urinary tract infection or pneumonia) spread via the blood to the bone.
- Direct contact: Bacteria enter the bone during an open fracture, a deep wound, or in connection with surgery (e.g., during the insertion of a joint prosthesis).
- Nearby tissue: An infection in soft tissues or an infected wound (e.g., foot or leg ulcers) spreads inward to the underlying bone.
When should you seek care?
Contact healthcare immediately if:
- You have severe bone pain combined with fever
- An area over a bone is red, warm, and swollen
- You have a wound that does not heal and the pain in the area increases
- You have recently undergone joint surgery and experience increasing pain
How to find out if you have a bone infection
If a bone infection is suspected, a rapid and thorough investigation is required; therefore, you should primarily contact the emergency department. A doctor first makes a clinical assessment and takes blood tests to check infection markers such as ESR and CRP.
If suspicion remains, diagnostic imaging is crucial; an MRI scan of the area may be relevant as it is the most sensitive method for early detection of a bone infection. With MRI, changes in the bone marrow, fluid accumulation, and inflammation in soft tissues can be seen long before they appear on a standard X-ray. This is critical for initiating the correct antibiotic treatment and preventing permanent damage to the bone.