Acute Osteomyelitis In Children

Acute osteomyelitis is infection of bone, usually from haematogenous bacterial spread. Metaphyseal regions of rapidly growing long bones are most often affected because their vascular architecture favours bacterial seeding.

Staphylococcus aureus is the dominant pathogen; Kingella kingae is increasingly important in children 6 to 48 months, while Salmonella should be considered in sickle cell disease.

Delayed treatment risks subperiosteal abscess, bone necrosis, pathological fracture, growth plate damage and chronic osteomyelitis.

Presentation is often acute with fever and focal bone pain. Young children may simply refuse to walk or use the affected limb.

• Localized bone tenderness, swelling and warmth
• Limp or refusal to weight bear
• Reduced movement of the adjacent joint because of pain
• Fever, irritability and reduced activity
• Pseudoparalysis in infants
• Back pain or neurological symptoms with vertebral disease

Persistent bacteraemia, severe systemic illness or rapidly increasing swelling should raise concern for abscess formation or aggressive S. aureus infection.

• Blood cultures should be obtained before antibiotics when this does not delay treatment. Positive blood cultures can establish the organism without invasive bone sampling.

• FBC, CRP and ESR support diagnosis and provide useful baselines. CRP is particularly useful for monitoring early treatment response, but normal inflammatory markers do not completely exclude early disease.

• Plain radiographs are useful initially to exclude fracture, tumour or another bone lesion, but may remain normal during the first 1 to 2 weeks.

• MRI with contrast is the imaging investigation of choice where the diagnosis is uncertain, symptoms are severe, or abscess, pyomyositis, joint involvement or spinal disease is suspected.

• Ultrasound can identify a subperiosteal collection but does not adequately assess marrow disease.

• Aspirate or biopsy bone or adjacent abscess for Gram stain, culture and susceptibility where blood cultures are negative, disease is complicated, or unusual organisms are suspected.

• Start empirical therapy active against S. aureus after cultures are obtained. Where methicillin resistant S. aureus prevalence is low, cefazolin 50 mg/kg IV every 8 hours, maximum 2 g per dose, or an antistaphylococcal penicillin such as flucloxacillin is appropriate.

• Where clinically significant community acquired MRSA is prevalent, use clindamycin 10 to 13 mg/kg IV every 8 hours, maximum 900 mg per dose, if local clindamycin susceptibility is reliable; otherwise use vancomycin approximately 15 mg/kg IV every 6 hours, adjusted using therapeutic drug monitoring and renal function.

• Narrow therapy once cultures identify the pathogen. For susceptible MSSA, beta lactam therapy is preferred over vancomycin.

• Clinical improvement, resolution of fever and falling CRP allow transition to an active oral agent such as cefalexin approximately 25 mg/kg PO every 6 hours, maximum 1 g per dose, for MSSA.

• Uncomplicated acute haematogenous osteomyelitis generally requires approximately 3 to 4 weeks total antimicrobial therapy. Longer treatment is required for virulent organisms, delayed response, abscess, extensive bone destruction or complications.

• Drain significant subperiosteal or intramuscular abscesses and obtain urgent orthopaedic input where source control is required.

Clinical toolsCalculators

BMI GCS EDD Parkland Formula

Corrected Sodium Corrected Calcium Anion Gap Creatinine Clearance Insulin Calculations qSOFA Wells PE Wells DVT CHA₂DS₂-VASc HAS-BLED CURB-65 Centor/McIsaac

Pelvic Fracture

Pelvic fractures range from stable pubic ramus injuries to complete disruption of the pelvic ring with massive retroperitoneal haemorrhage.

A pelvic ring injury should be approached first as a potential haemorrhagic emergency, not merely an orthopaedic fracture.

Major bleeding sources include:

Presacral and pelvic venous plexus
Exposed cancellous bone
Internal iliac arterial branches

The retroperitoneum can contain several litres of blood.

Associated injuries frequently involve:

Bladder
Urethra
Rectum
Vagina
Abdominal viscera
Spine
Major nerves

Tile classification

Based on mechanical stability.

Type A: Stable

Posterior arch remains stable.

Avulsion or fracture not significantly involving pelvic ring stability.

Stable or minimally displaced pelvic ring fracture.

Transverse sacral fracture.

Type B: Rotationally unstable, vertically stable

Open book injury.

Lateral compression injury.

B2.1 typically involves ipsilateral anterior ring injury.

B2.2 may produce a contralateral bucket handle pattern.

Bilateral rotational instability.

Type C: Rotationally and vertically unstable

Unilateral complete instability.

Subclassified according to posterior lesion through:

Ilium
SI joint
Sacrum

Bilateral injury with one side type C and the opposite side type B.

Bilateral complete instability.

Young Burgess classification

Based on force direction.

Anterior posterior compression

APC I

Symphyseal widening below approximately 2.5 cm
Posterior SI ligaments intact
Usually mechanically stable or minimally unstable

APC II

Symphyseal widening greater than approximately 2.5 cm
Anterior SI joint opening
Sacrospinous and sacrotuberous ligament disruption
Posterior SI ligaments intact

Rotationally unstable but vertically stable.

APC III

Complete anterior and posterior SI ligament disruption
Complete hemipelvic instability
High haemorrhage risk

Lateral compression

LC I

Pubic ramus fracture
Ipsilateral sacral compression fracture

Most common pelvic ring pattern.

LC II

Rami injury plus posterior iliac crescent fracture through the SI complex

LC III

Ipsilateral lateral compression with contralateral external rotation injury

Called a windswept pelvis.

Vertical shear

Vertical displacement of one hemipelvis with complete posterior ligament disruption.

Severely unstable and associated with major bleeding and neurological injury.

Denis sacral zones

Useful when the posterior injury passes through the sacrum.

Zone I

Lateral to neural foramina.

Lowest neurological risk.

Zone II

Through neural foramina.

Risk of radicular injury.

Zone III

Central sacral canal.

Highest risk of cauda equina, bowel and bladder dysfunction.

Follow major trauma resuscitation principles.

Inspect for:

Pelvic deformity
Perineal bruising
Scrotal or labial haematoma
Rectal bleeding
Vaginal bleeding
Open wounds
Leg length discrepancy
Neurological deficit

Do not repeatedly spring or compress the pelvis after an unstable injury has been identified because repeated manipulation can disrupt clot.

Look for urethral injury:

Blood at urethral meatus
Inability to void
Perineal haematoma
High risk pelvic ring pattern

Perform retrograde urethrography before blind catheterisation when urethral disruption is suspected.

Open pelvic fractures involving rectum or perineum have extremely high septic and haemorrhagic morbidity.

Haemorrhage control

In an unstable pelvic ring injury, apply a pelvic binder over the greater trochanters, not around the iliac crests.

The binder:

Reduces pelvic volume in APC injury
Improves tamponade
Stabilises fracture surfaces

Initiate balanced haemostatic resuscitation when major bleeding is present.

A practical massive transfusion strategy uses approximately:

Packed red cells : plasma : platelets in a 1 : 1 : 1 ratio during active uncontrolled haemorrhage.

Correct:

Hypothermia
Acidosis
Hypocalcaemia
Coagulopathy

Persistent haemodynamic instability requires rapid haemorrhage control.

Options include:

Preperitoneal pelvic packing
External pelvic fixation or pelvic C clamp where appropriate
Angiography with arterial embolisation

These are complementary rather than competing techniques.

Angioembolisation is particularly effective when CT or ongoing physiology suggests arterial bleeding.

Preperitoneal packing rapidly controls predominantly venous and cancellous bleeding and is valuable in an unstable patient requiring immediate operative control.

Temporary mechanical stabilisation

APC injuries can be stabilised using:

Binder
Anterior external fixator
Pelvic C clamp in selected posterior instability

Vertical shear may require:

Skeletal traction
Temporary external fixation
Definitive posterior fixation

Stable pelvic fracture

Tile A and many LC I injuries can be managed nonoperatively.

Provide analgesia and mobilise early with protected weight bearing according to pain and stability.

Prolonged bed rest should be avoided.

Operative indications

Fixation is appropriate for:

APC II and III instability
Vertical shear
Tile C fracture
Displaced crescent fracture
Symptomatic unstable posterior ring injury
Progressive displacement
Open unstable pelvic fracture
Selected LC injuries demonstrating instability under stress

Posterior ring

Posterior stability is critical.

Options include:

Percutaneous iliosacral screws
Transsacral screws
Posterior plating
Lumbopelvic fixation for severe spinopelvic dissociation

Careful preoperative CT assessment is mandatory because sacral dysmorphism alters safe screw corridors.

Anterior ring

Options include:

Symphyseal plate
Ramus screw
External fixation

In vertically unstable injuries, anterior fixation alone is inadequate. The posterior ring must also be stabilised.

Open pelvic fracture

Urgently address:

Haemorrhage
Faecal contamination
Urinary injury
Devitalised perineal tissue
Unstable bone

Broad antimicrobial coverage is required when rectal or gross perineal contamination exists, for example:

Piperacillin tazobactam 4.5 g IV every 8 hours by extended infusion, renal adjusted.

Perform repeated debridement as necessary.

Faecal diversion is considered with:

Rectal injury
Massive perineal contamination
Destructive anorectal injury

It is not mandatory for every open pelvic wound.

VTE prophylaxis

Pelvic fracture carries high venous thromboembolism risk.

Begin pharmacological prophylaxis once haemostasis is secure and bleeding risk is acceptable.

A commonly used regimen is:

Enoxaparin 40 mg subcutaneously once daily, with adjustment for renal function, body weight and local trauma protocol.

Major complications include:

Fatal haemorrhage
DVT or pulmonary embolism
Pelvic sepsis
Neurological injury
Chronic pelvic pain
Sexual dysfunction
Urological dysfunction
Malunion
Leg length discrepancy

Acute Osteomyelitis In Children

Overview

Clinical Features

Diagnosis

Management

Overview

Clinical Features

Diagnosis

Management