Osteomyelitis (Bone Infection) Causes, Symptoms, Treatment

Osteomyelitis is a serious bone condition that requires early diagnosis and prompt treatment to prevent  complications such as bone deformities, chronic pain, or systemic infection. It usually presents with persistent bone pain, fever, or swelling with immediate medical attention, it can be easily treated without complete recovery and no serious long term complications.

What is osteomyelitis?

Osteomyelitis is a serious medical condition characterized by an infection of the bone. It is mainly caused by bacteria that reach the bone either directly, like with a penetrating injury, or through the bloodstream from other site. It can affect any bone in the body but is most commonly seen in the long bones of the arms and legs in children and the vertebrae in adults. The infection may develop suddenly (acute) or persist over time (chronic), often leading to bone damage if not treated promptly.

Causes of Osteomyelitis

A bone infection (osteomyelitis) occurs when bacteria or, in some cases, fungi invade the bone tissue. The infection can arise in several ways:

1. Haematogenous Spread: Bacteria or fungi from another part of the body travel through the bloodstream and infect the bone. This is more common in children.
2. Direct Contamination: Open fractures, surgical procedures, or puncture wounds can allow microorganisms to directly enter the bone.
3. Contiguous Spread: An infection in nearby tissues, such as a diabetic foot ulcer, can spread to the bone.
4. Weakened Immune System: Conditions like diabetes, cancer, or the use of immunosuppressive medications increase the risk of infection.

The most common causative agent is a bacterium known as Staphylococcus aureus, which is widely present in our environment and even on the surface of our skin. A common drug resistant strain, known as  methicillin-resistant Staphylococcus aureus (MRSA), can also cause osteomyelitis, as well as a range of other bacterial and fungal species.

Symptoms of Osteomyelitis

The signs and symptoms of osteomyelitis can vary depending on its location, the patient’s age, and the severity of the infection. Common symptoms include:

• Pain and swelling: Tenderness and swelling at and often around the site of the infection.
• Fever and chills
• Redness and warmth: Indicates inflammation around the affected area.
• Limited Range of Motion: Difficulty moving the affected limb or joint.
• Fatigue: General feelings of weakness and malaise.
• Oozing wound: In chronic osteomyelitis, pus may drain from an open wound near the infected area.

Diagnosis of Osteomyelitis

Accurate diagnosis is critical for effective treatment and prevention of complications.

• Medical history and physical examination: A doctor will examine the area and ask a range of questions about symptoms, recent injuries, surgeries, or infections.
• Imaging Studies:
  – X-rays: To detect bone changes, though these may only appear in advanced stages.
  – MRI (Magnetic Resonance Imaging): Provides detailed images of soft tissue and bone, useful for early detection.
  – CT (Computed Tomography) Scan: Offers cross-sectional views of the affected area.
• Laboratory Tests:
  – Blood Tests: Elevated white blood cell count and inflammatory markers like C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR).
  – Blood Cultures: To identify the causative microorganism.
  – Bone Biopsy: A definitive test where a sample of bone tissue is obtained for microbial analysis to identify the specific organism causing the infection.

Treatment of Osteomyelitis

Treatment aims to eradicate the infection and restore bone function. The following strategies are commonly used:

• Antibiotics: High doses of intravenous (IV) antibiotics are the first-line treatment for bacterial infections. The duration of therapy can range from 4 to 6 weeks or longer, depending on the severity.
• Surgery:
  – Debridement: Removal of infected and necrotic bone tissue.
  – Drainage: Clearing any abscesses or pus collections.
  – Bone Reconstruction: In severe cases, bone grafts or stabilization with metal hardware may be necessary.

It is important that underlying conditions are treated and appropriately managed, like controlling diabetes or improving immune function can enhance recovery. Supportive measures may include pain management and physical therapy to regain mobility and strength. Chronic osteomyelitis may require long-term antibiotic therapy or additional surgeries to prevent recurrence.