Makindo Medical Notes

🦠 In patients with Sickle cell disease → Staph aureus and Salmonella are the key organisms to remember.

ℹ️ About

• 🦴 Infection of bone → causes pain, deformity, chronic disability if untreated
• ⏱ A surgical + paediatric + microbiological emergency

🧾 Aetiology

🔴 Usually haematogenous spread → infection seeds in the metaphyses of long bones (slow flow + microtrauma encourage seeding).

• 📊 Different presentation in adults vs children
• 🧬 Strong link with sickle cell disease
• 🌍 Source: skin, urine, chest infection, IVDU

🧫 Microbiology

• 👑 Staphylococcus aureus (85%)
• 💉 IVDU/urosepsis → E. coli, Pseudomonas, Klebsiella
• 🍗 Salmonella (classically sickle cell)
• 👶 Neonates → Group B strep, E. coli, H. influenzae
• 🧪 Fungal (immunocompromised)

🔀 Types

• 🩹 Direct: open fracture, wound, post-op
• 🩸 Indirect: blood-borne seeding

👨 Adult vs 👶 Child

• 👨 >45 yrs → vertebral osteomyelitis (blood flow changes)
• 🌍 TB still important worldwide
• 👶 Children → long bone metaphysis, often vague systemic features, “won’t walk”
• 💉 Neonates: S. aureus, GBS, E. coli
• After 1 yr: S. aureus, Strep pyogenes, H. influenzae (↓ with vaccine)

⚠️ Risk Factors

• 🚬 Diabetes, alcoholism, chronic steroids
• 💉 IVDU → vertebral involvement
• 🧬 Immunosuppression (AIDS, transplant, chemotherapy)
• 🦠 Sickle cell disease
• 🦵 Prostheses, open fractures

🩺 Clinical

• 🔥 Toxic, febrile, rigors
• 🦴 Localised bone pain, tenderness, warmth, swelling
• 👶 Children → limp, refusal to weight bear, or just irritability/PUO
• ⚠️ Can mimic trauma, malignancy, or septic arthritis

🔍 Investigations

• 🩻 X-ray: insensitive early (2–4 weeks before changes)
• 💀 Sequestrum (dead bone), Involucrum (new bone), Brodie’s abscess
• 🧲 MRI: gold standard — marrow oedema, soft tissue/joint involvement
• 🩺 USS: may show periosteal lift/collection
• ☢️ Bone scan (if MRI unavailable)
• 🧪 Blood cultures (positive in ~50%)
• 📈 CRP/ESR ↑, WCC ↑
• 🔬 Biopsy/aspirate for culture BEFORE antibiotics if possible

🤔 Differentials

• Synovitis
• Trauma/fracture
• Bone tumour (e.g. Ewing’s, osteosarcoma)

💊 Management (with Microbiology input)

💡 Principles: Antibiotics + rest/splintage + drainage if pus present. Debate remains on IV vs oral duration (often 4–6 weeks IV initially).

• 💉 Empiric: Flucloxacillin + Fusidic acid (UK practice) → tailor by cultures
• 🦠 Specific:
  • Staph aureus → IV penicillin or vancomycin + rifampicin
  • Strep → Penicillin
  • Anaerobes → Clindamycin or metronidazole
  • Pseudomonas → Ciprofloxacin
• 🔪 Surgery:
  • Drain/debride necrotic tissue
  • Fill dead space (flaps/bone graft)
  • Stabilise bone (internal/external fixation)
  • Amputation if uncontrolled