Osteomyelitis is an acute or chronic bone infection that can be caused by bacteria or less commonly, by fungi.
Infection may spread to a bone from infected skin, muscles or tendons next to the bone, as in osteomyelitis that occurs under a chronic skin ulcer (sore). The infection that causes osteomyelitis can also start in another part of the body and spread to the bone through the blood.
A current or past injury may have made the affected bone more likely to develop the infection. A bone infection can also start after bone surgery, especially if the surgery is done after an injury or if metal rods or plates are inserted in the bone.
In children, the long bones are usually affected. In adults, the feet, spine and the hips are most commonly affected.
Risk factors include:
- Injected drug use
- Poor blood supply
- Recent trauma
People who have had their spleen removed are also at higher risk for osteomyelitis.
- Bone pain
- General discomfort, uneasiness or malaise
- Swelling, redness and warmth in the affected area
- Excessive sweating
- Low back pain
- Swelling of the ankles, feet and legs
A physical examination shows bone tenderness and possibly swelling and redness. Tests may include:
- Blood cultures
- Bone biopsy
- Bone scan
- Bone x-ray
- Complete blood count (CBC)
- C-reactive protein (CRP)
- Erythrocyte sedimentation rate (ESR)
- MRI of the bone
- Needle aspiration of the area around the affected bones
The goal of treatment is to cure the infection and reduce damage to the bone and surrounding tissues.
Antibiotics are given to destroy the bacteria causing the infection. Your doctor may prescribe more than one antibiotic at a time. Often, the antibiotics are given intravenously (through a vein) rather than by mouth. They are prescribed for at least 4 to 6 weeks, sometimes longer.
Surgery may be needed to remove dead bone tissue if you have an infection that is difficult to cure. If there are metal plates near the infection, they may need to be removed. The open space left by the removed bone tissue may be filled with bone graft or packing material that promotes the growth of new bone tissue.
If you have diabetes, your disease will need to be well controlled. If there are problems with blood supply to the infected area, such as the foot, surgery to improve blood flow may be needed.
With treatment, the outcome for acute osteomyelitis is usually good.
Source: National Institutes of Health