Osteomyelitis
Definition
Osteomyelitis is an acute or chronic bone infection.
Causes
Bone infection can be caused by bacteria or fungi.
- Infection may also 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 placed in the bone.
In children, the long bones are usually affected. In adults, the feet, spine bones (vertebrae), and the hips (pelvis) are most commonly affected.
Risk factors are recent trauma, diabetes, hemodialysis, poor blood supply, and IV drug abuse. People who have had their spleen removed are also at higher risk for osteomyelitis.
Symptoms
- Bone pain
- Fever
- General discomfort, uneasiness, or ill-feeling (malaise)
- Local swelling, redness, and warmth
- Nausea
Additional symptoms that may be associated with this disease:
- Chills
- Excessive sweating
- Low back pain
- Swelling of the ankles, feet, and legs
Exams and Tests
A physical examination shows bone tenderness and possibly swelling and redness.
Tests may include:
- Blood cultures
- Bone biopsy (which is then cultured)
- Bone scan
- Bone x-ray
- C-reactive protein (CRP)
- Erythrocyte sedimentation rate (ESR)
- MRI
- Needle aspiration of the area around affected bones
Treatment
The objective of treatment is to eliminate the infection and prevent it from getting worse.
Antibiotics will be given to destroy the bacteria that are causing the infection. You may be given more than one antibiotic at a time. Often, the antibiotics are given through an IV (intravenously, meaning through a vein) rather than by mouth. Antibiotics are taken for at least 4-6 weeks, sometimes longer.
Surgery may be needed to remove dead bone tissue if you have an infection that does not go away. If there are metal plates near the infection, they may 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.
Infection of an orthopedic prosthesis may require surgical removal of the prosthesis and infected tissue surrounding the area. A new prosthesis may be implanted in the same operation or delayed until the infection has gone away.
If the patient has diabetes, it will need to be well controlled. If there are problems with blood supply, surgery to improve blood flow may be needed.
Outlook (Prognosis)
When treatment is received, the outcome for acute osteomyelitis is usually good.
The outlook is worse for those with long-term (chronic) osteomyelitis, even with surgery. Amputation may be needed, especially in those with diabetes or poor blood circulation.
The outlook is guarded in those who have an infection of a prosthesis.
Possible Complications
When the bone is infected, pus is produced within the bone, which may result in an abscess. The abscess steals the bone's blood supply. The lost blood supply can result in a complication called chronic osteomyelitis. This chronic infection can cause symptoms that come and go for years.
Other complications include:
- Need for amputation
- Reduced limb or joint function
- Spread of infection
When to Contact a Medical Professional
Call your health care provider if you develop symptoms of osteomyelitis, or if you have osteomyelitis and the symptoms continue despite treatment.
Prevention
Prompt and complete treatment of infections is helpful. High-risk people should see a health care provider promptly if they have signs of an infection anywhere in the body.
References
Espinoza LR. Infections of Bursae, Joints, and Bones. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 293.
Gutierrez KM. Osteomyelitis. In: Long SS, Pickering LK, Prober CG. Principles and Practice of Pediatric Infectious Diseases. 3rd ed. Philadelphia, Pa : Churchill Livingstone Elsevier; 2008: chap: 80.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
