Published: 18 Jun 2025

ICD9: 730      ICD10: M86.9      ICD11: FB84

Osteomyelitis is an infection of the bone.
It can be caused by bacteria, fungi, or viruses. Bacteria are the most common cause, often Staphylococcus aureus.

Here's a breakdown of key aspects:

Causes:

Bacteria: Most commonly Staphylococcus aureus. Other bacteria include Streptococcus, Enterobacter, and Pseudomonas.
Fungi: Less common, but possible, especially in people with weakened immune systems.
Viruses: Rare.
How it gets there:
Through the bloodstream (Hematogenous Osteomyelitis): This is more common in children. An infection somewhere else in the body (like a skin infection or pneumonia) can spread to the bone via the bloodstream.
Direct infection: This happens when bacteria enter the bone directly, usually after a trauma (like a fracture or surgery), a wound (like a puncture wound), or a prosthetic joint infection.
Spread from nearby infection: An infection in nearby tissue can spread to the bone. This is often seen in people with diabetes and foot ulcers.

Risk Factors:

Age: Children and older adults are more susceptible.
Diabetes: Poor circulation and impaired immune function increase the risk.
Compromised immune system: Conditions like HIV/AIDS, cancer treatment, or long-term steroid use weaken the immune system.
Sickle cell disease: Can damage blood vessels, making bones more vulnerable to infection.
Intravenous drug use: Increases the risk of bloodstream infections.
Recent injury or surgery: Provides a direct route for bacteria to enter the bone.
Poor circulation: Conditions like peripheral artery disease make it harder for the body to fight infection.
Prosthetic joints or metal implants: Bacteria can attach to these and cause infection.
Hemodialysis: increases the risk of infection.

Symptoms:

Symptoms vary depending on the severity and location of the infection, but may include:

Pain: Bone pain in the affected area.
Fever: Often present, especially in acute cases.
Chills: Shaking chills may accompany fever.
Swelling, redness, and warmth: Around the affected bone.
Tenderness: To the touch over the affected area.
Fatigue: Feeling tired and weak.
Drainage: Pus may drain from a wound near the infected bone.
In children: Irritability, refusal to use an arm or leg.

Types:

Acute Osteomyelitis: Develops rapidly, usually within a few days or weeks.
Chronic Osteomyelitis: Develops slowly over a longer period, and may be difficult to treat. It can persist for months or years, with periods of flare-ups and remissions.
Vertebral Osteomyelitis: Infection of the bones in the spine.
Osteomyelitis due to vascular insufficiency: This type is caused by poor blood flow to the bone, commonly found in the feet of people with diabetes.

Diagnosis:

Physical exam: The doctor will examine the affected area.
Blood tests: To look for signs of infection, such as an elevated white blood cell count and erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP).
Imaging tests:
X-rays: Can show bone damage, but may not be apparent early in the infection.
MRI (Magnetic Resonance Imaging): More sensitive than X-rays and can detect early signs of infection.
CT scan (Computed Tomography): Can provide detailed images of the bone.
Bone scan: Uses radioactive material to highlight areas of increased bone activity, which can indicate infection.
Bone biopsy: A sample of bone is taken and examined under a microscope to identify the specific organism causing the infection. This is the gold standard for diagnosis.

Treatment:

Antibiotics: Usually given intravenously (IV) for several weeks, followed by oral antibiotics. The specific antibiotic will depend on the organism causing the infection.
Surgery: May be necessary to:
Drain pus or infected fluid: Debridement.
Remove dead or infected bone tissue: This is critical in chronic cases.
Stabilize the bone: If there is a fracture.
Remove any infected hardware: Such as plates, screws, or prosthetic joints.
Wound care: Proper wound care is important to prevent further infection.
Hyperbaric oxygen therapy: May be used in some cases to promote healing.

Complications:

Chronic osteomyelitis: Persistent infection.
Bone death (Avascular Necrosis): If the blood supply to the bone is cut off.
Septic arthritis: Infection of a nearby joint.
Impaired growth: In children, osteomyelitis can affect bone growth.
Amputation: In severe cases, amputation may be necessary.
Sepsis: A life-threatening bloodstream infection.

Prevention:

Good hygiene: Washing hands frequently and keeping wounds clean can help prevent infection.
Prompt treatment of infections: Treating infections early can prevent them from spreading to the bone.
Proper wound care: Keeping wounds clean and covered can help prevent infection.
Careful management of diabetes: Controlling blood sugar levels can help prevent complications, including osteomyelitis.
Avoid intravenous drug use: Reduces the risk of bloodstream infections.

In summary, osteomyelitis is a serious bone infection that requires prompt diagnosis and treatment. If you suspect you have osteomyelitis, see a doctor right away.