Osteomyelitis is a bone infection, usually caused by bacteria, and less commonly by fungi. It can be acute (sudden and severe) or chronic (long-lasting and recurring). If not treated promptly, osteomyelitis can cause permanent bone damage, loss of function, or amputation.
🧬 What Causes Osteomyelitis?
The infection can reach the bone in one of three ways:
1. Hematogenous Spread (Most Common in Children)
- Bacteria travel through the bloodstream from another infected area (e.g., lungs, skin, urinary tract)
2. Contiguous Spread (More Common in Adults)
- Infection spreads from nearby tissues (e.g., a diabetic foot ulcer, cellulitis, or surgical wound)
3. Direct Inoculation
- Bacteria enter directly through trauma, open fractures, or surgical procedures
🦠 Common Bacteria Involved
| Organism | Notes |
|---|---|
| Staphylococcus aureus (including MRSA) | Most common cause of osteomyelitis |
| Streptococcus species | Often in hematogenous spread |
| Pseudomonas aeruginosa | Common in puncture wounds, IV drug use |
| Salmonella | Seen in patients with sickle cell disease |
⚠️ Risk Factors
- Diabetes (especially with foot ulcers)
- Recent surgery or orthopedic implants
- Open fractures or wounds
- Peripheral artery disease or poor circulation
- Immunocompromised state (e.g., cancer, HIV)
- Intravenous drug use
- Chronic skin infections or pressure sores
🩺 Symptoms of Osteomyelitis
| Local Symptoms | Systemic Symptoms |
|---|---|
| Bone pain (deep, aching) | Fever and chills |
| Swelling and warmth over area | Fatigue |
| Redness over the affected bone | Nausea or malaise (in severe cases) |
| Limited movement or stiffness | Night sweats |
| Wound that won’t heal | Pus drainage (sometimes) |
In chronic osteomyelitis, there may be no fever, but ongoing pain, swelling, or draining sinus tracts.
🔍 How Is It Diagnosed?
- Physical Exam
- Blood Tests:
- Elevated white blood cell count
- C-reactive protein (CRP) and ESR (inflammation markers)
- Imaging:
- X-rays (may show changes after 1–2 weeks)
- MRI (most sensitive for early detection)
- Bone scan or CT (in certain cases)
- Bone biopsy or aspiration:
- Confirms diagnosis and identifies the exact organism causing the infection
💊 Treatment of Osteomyelitis
✅ Acute Osteomyelitis:
- IV antibiotics for 4–6 weeks
- Targeted antibiotics based on culture results
- May switch to oral antibiotics if infection improves
✅ Chronic Osteomyelitis:
- Surgery to remove infected or dead bone (debridement)
- Antibiotics (IV or long-term oral)
- Sometimes bone grafts or reconstructive surgery
🛡️ Complications (If Not Treated Promptly):
- Bone death (necrosis)
- Abscesses or sinus tract formation
- Chronic pain and swelling
- Sepsis (infection spreading to the bloodstream)
- Loss of limb function or amputation
🧠 Summary Table:
| Feature | Osteomyelitis |
|---|---|
| Definition | Infection of the bone |
| Common causes | Bacteria, especially Staph aureus |
| Entry routes | Bloodstream, nearby tissue, direct trauma |
| Common sites | Long bones (kids), spine, feet (diabetics), pelvis |
| Symptoms | Pain, swelling, fever, fatigue |
| Diagnosis | MRI, blood tests, biopsy |
| Treatment | Antibiotics ± surgery |
| Risk factors | Diabetes, poor circulation, open wounds, implants |