Synopsis
Recognise blood-borne bone infection early, distinguish a stable child from sepsis or a drainable focus, obtain meaningful cultures, and coordinate antibiotics, imaging, source control and growth-aware follow-up.
- A limping, non-weight-bearing or pseudoparalysed child with focal bone tenderness and fever has osteomyelitis until a safer explanation is established; early skin and radiographs may look normal.
- Admit all children with suspected acute musculoskeletal infection for combined paediatric and orthopaedic care and examine the whole child, spine and adjacent joints.
- Initial investigations are FBC, CRP, blood cultures and ESR in the BOASt sequence, plus plain radiographs of the relevant bone and joint; no single result excludes disease.
- MRI is the preferred second-line modality, ideally within 48 hours, and sooner when deterioration or a deep collection is suspected; ultrasound helps identify an effusion or superficial collection.
- Give empirical intravenous antibiotics immediately in high-risk sepsis. If stable and surgery is planned promptly, senior teams may defer antibiotics briefly to obtain deep samples.
- First-line treatment of uncomplicated acute osteomyelitis is intravenous antibiotics; abscess, septic joint, necrotic tissue or poor response creates a drainage or debridement question.
- Use clinical recovery and serial temperature, CRP, ESR and white-cell trends to decide intravenous-to-oral switch and total course with microbiology, not an isolated normal value.
- Follow clinically and radiographically for at least 12 months with expertise able to recognise recurrent infection, physeal arrest, deformity and functional loss.
Key red flags
Shock, altered behaviour, mottling, oliguria, rising lactate or rapidly worsening limb pain indicates systemic danger and requires parallel sepsis treatment and orthopaedic source-control planning.
A painful immobile joint beside the affected metaphysis, especially the hip or shoulder where the metaphysis may lie within the capsule, raises concern for associated septic arthritis requiring urgent drainage.
Fluctuance, marked swelling, persistent fever or failure of CRP and symptoms to improve after appropriate therapy suggests a subperiosteal, soft-tissue or intraosseous collection.
Back pain, neurological deficit, multifocal tenderness, chest symptoms or a new murmur suggests vertebral, multifocal, pulmonary or endovascular spread and widens imaging and specialist assessment.
Investigation priorities
Assess inflammation, cytopenia and a baseline for response.
Map marrow, cortex, physis, joint and soft-tissue extension.
Management branches
High-risk sepsis, organ dysfunction or rapid clinical decline accompanies suspected bone infection.
- Call paediatrics, orthopaedics, anaesthesia and microbiology and apply the current sepsis pathway without waiting for imaging.
- Take blood cultures and essential tests immediately, then give empirical intravenous antibiotics with no avoidable delay.
- Image urgently enough to find septic joint, abscess or another focus and move directly to drainage when indicated.
- Reassess perfusion, lactate, urine output, pain and all potential metastatic sites through resuscitation and source control.
The child is physiologically stable and definitive sampling or surgery can occur promptly.
- Complete paediatric and orthopaedic examination, FBC, CRP, blood cultures, ESR and plain radiographs.
- Arrange preferred MRI and ultrasound within 48 hours or sooner according to pain, site and clinical trajectory.
- If theatre is planned, make an explicit senior decision whether a short antibiotic delay safely improves deep-sample yield.
- Start policy-based intravenous therapy after samples and tailor promptly to culture, allergy, weight and organ function.