🦠 In patients with Sickle cell disease → Staph aureus and Salmonella are the key organisms to remember. Osteomyelitis is an acute bacterial infection of bone that can rapidly compromise blood supply, leading to necrosis, growth plate damage, and permanent disability if treatment is delayed. Haematogenous spread is most common in children, particularly affecting metaphyseal regions.

🚨🦴 Suspected Osteomyelitis - Orthopaedic Emergency (Especially in Children)
🏥 Emergency Referral Immediate orthopaedic and paediatric assessment required - do not delay for imaging. 🦴 Key Clinical Features Severe localised bone pain, swelling, warmth, erythema, and marked tenderness, often without trauma. 🤒 Systemic Illness Fever, rigors, lethargy, poor feeding, and refusal to weight-bear or move the limb (pseudoparalysis). 🧪 Urgent Investigations FBC, CRP, ESR, blood cultures (before antibiotics if possible), and early MRI (gold standard). 📞 Specialist Involvement Early discussion with Orthopaedics and Microbiology/Infectious Diseases is essential. 💉 Definitive Management Prompt IV antibiotics (targeting Staphylococcus aureus initially) ± surgical drainage/debridement. ⚠️ Complications if Delayed Sepsis, chronic osteomyelitis, growth disturbance, pathological fracture, limb deformity. 🧠 Teaching Pearl A child who refuses to weight-bear with fever and raised CRP should be assumed to have bone or joint infection (septic arthritis or osteomyelitis) until proven otherwise. Early antibiotics within hours - not days - prevents irreversible bone injury.

🚨🦴 Suspected Osteomyelitis - Orthopaedic Emergency (Especially in Children)

🏥 Emergency Referral Immediate orthopaedic and paediatric assessment required - do not delay for imaging.
🦴 Key Clinical Features Severe localised bone pain, swelling, warmth, erythema, and marked tenderness, often without trauma.
🤒 Systemic Illness Fever, rigors, lethargy, poor feeding, and refusal to weight-bear or move the limb (pseudoparalysis).
🧪 Urgent Investigations FBC, CRP, ESR, blood cultures (before antibiotics if possible), and early MRI (gold standard).
📞 Specialist Involvement Early discussion with Orthopaedics and Microbiology/Infectious Diseases is essential.
💉 Definitive Management Prompt IV antibiotics (targeting Staphylococcus aureus initially) ± surgical drainage/debridement.
⚠️ Complications if Delayed Sepsis, chronic osteomyelitis, growth disturbance, pathological fracture, limb deformity.

🧠 Teaching Pearl
A child who refuses to weight-bear with fever and raised CRP should be assumed to have bone or joint infection (septic arthritis or osteomyelitis) until proven otherwise. Early antibiotics within hours - not days - prevents irreversible bone injury.

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

Case 1 – Diabetic foot osteomyelitis

67-year-old with long-standing diabetes presents with a plantar ulcer at the 1st MTP, foul discharge, and a “probe-to-bone” positive test. CRP 98 mg/L, ESR 68 mm/h, X-ray shows cortical erosion; MRI confirms osteomyelitis of the distal first metatarsal. Start empiric IV antibiotics covering S. aureus (incl. MRSA risk) and gram-negatives, optimise glycaemic control and perfusion, obtain deep tissue/bone cultures, and involve multidisciplinary foot team for surgical debridement ± limited resection. Plan 6 weeks of targeted therapy once cultures return.

Case 2 – Vertebral osteomyelitis from S. aureus bacteraemia

59-year-old with 2 weeks of severe low back pain, nocturnal sweats, and recent S. aureus bacteraemia. Exam: vertebral tenderness; no focal neurology. CRP 130 mg/L. MRI spine shows L3–L4 discitis/osteomyelitis with small epidural phlegmon. Obtain repeat blood cultures, screen for endocarditis (TTE/TOE), and start IV anti-staphylococcal therapy (e.g., flucloxacillin if MSSA). Neurosurgical input for any neurological deficit, instability, or large abscess. Treat 6–12 weeks guided by response and microbiology.

Case 3 – Post-traumatic tibial osteomyelitis

45-year-old after an open tibial fracture fixed with metalwork develops persistent wound drainage and pain 3 months post-op. CRP 72 mg/L; X-ray shows periosteal reaction; MRI suggests sequestrum. Take deep samples off antibiotics during debridement; consider removal/exchange of hardware if unstable or infected biofilm suspected. Start targeted IV antibiotics then step down to oral to complete ~6 weeks (longer if dead bone/hardware retained). Coordinate with orthoplastics for debridement, dead space management, and soft-tissue coverage.

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Osteomyelitis