Paediatric Lower Limb Fractures

SUFE

• Aetiology is unknown
• Relatively common. 0.2-10 per 100 000 population
• More common in boys (60%)
• Mean age of diagnosis 13.5 years in boys and 12 in girls
• 50% of adolescents with SUFE are obese
• Bilateral in 18-50% of patients

• Acute
  • Presents with sudden onset pain in hip and inability to walk
  • Vague pain in groin, thigh or knee
  • Knee pain is commonly the only complaint
• Chronic
  • Antalgic gait
  • Out-toeing
  • Some shortening of affected limb
  • Obligatory external rotation during flexion of hip is a reliable sign
  • Common to see misdiagnosis of knee pain and delayed dx of SUFE

• Ix
  • AP and frog lateral of both hips should be ordered
  • Frog lateral not performed in acute, unstable SUFE due to potential for displacement
    • Cross-table lateral X-ray can be performed
• Rx
  • Keep non-weight-bearing
  • All need surgery and orthopaedic referral
• Complications
  • Osteonecrosis – 50% if unstable SUFE, even if treated
  • Chondrolysis – Typically from screw/pin misplacement. 7%
  • Osteoarthritis
  • Impingement

Hip dislocation

• Rare in children and suggests significant trauma if older child or can occur in those <5yo with minor trauma
• Typically without fracture
• Presentation
  • Uncomfortable, not moving leg. Leg appears shortened. 
  • Anterior dislocation – Abducted and externally rotated
  • Posterior dislocation – Adducted and internally rotated with hip in flexed position
• Ideally reduce in theatre. Rarely may need to be done in ED

• Complications
  • AVN of femoral head
    • 3-15% risk
    • Significant risk if not reduced within 6 hours
  • Nerve injury (2-10%)
  • Femoral head overgrowth (coxa magna)
  • Osteoarthritis (acetabular fractures)
  • Recurrent dislocation
  • Growth arrest

Neck of femur fractures

• High energy trauma and rare in children
• Delbet classification
  • Type I: Through physis (5%)
  • Type II: Transcervical (50%)
  • Type III: Base of neck (25-30%)
  • Type IV: Intertrochanteric (15%)
• Management
  • Reduce in theatre

• Complications
  • AVN of femoral head: Delbet type I (100%), type II (61%), type III (27%) and type IV (14%)
  • Coxa vara: Neck-shaft ankle <120 degrees. Seen in up to 30%
  • Growth arrest: Associated with AVN and transphyseal fixation. Contributes 15% to limb length
  • Chondrolysis
  • Infection (<1%)

Femoral shaft

• Peak in early childhood and early adolescence
• In older children, high energy trauma in 90%
• In younger children, due to falls
• If under 4yo, 30% associated with NAI
• If not yet walking, must rule out NAI
• Rx
  • Put in skin traction (10% of body weight) + femoral nerve block
  • Thomas splint if transported
• If hypotensive, consider alternative cause for shock

Tibial shaft

• Direct trauma produces transverse or segmental fractures
• Rotational forces produce spiral fracture
• 30% associated with fibular fracture
• Toddlers fractures
  • Occur in young ambulatory children 9 months to 3yo
  • Spiral or oblique, non-displaced distal tibial shaft fracture with intact fibula
  • Periosteum remains intact and bone is stable
  • Occur through twisting
  • May not be visible on X-ray for first week (oblique views may help)
    • May be visible at 7-10 days once periosteal reaction occurs
  • Must exclude alternate cause for limb pain (septic arthritis, osteomyelitis)

Tibial shaft – Reduction?

• Toddlers – No reduction. Backslab can be applied
• Undisplaced tibial shaft – Procedural sedation for above-knee cast with knee flexed 30-40 degrees and ankle in neutral dorsiflexion
• Displaced – Closed reduction in procedural sedation
  • If unstable, may require GA and MUA
  • Above knee cast

• Complications
  • Compartment syndrome
    • If concerned, splint and delay casting until swelling reduced. Close clinical observation is recommended
  • Vascular injury
    • Proximal tibial shaft fractures at very high risk of vascular injury
  • Angular deformity
    • Isolated tibial fractures (with intact fibula) are at risk of tibial varus angular deformity so need close follow-up in first 3 weeks

Ankle fractures

• Classified by Salter-Harris classification
• Closure of the distal tibial physis occurs asymmetrically
  • Central closure first
  • Medial closure second
  • Lateral closure third
• Results in transitional fractures
  • Tillaux fracture – Salter-Harris III fracture with avulsion of anterolateral corner of distal tibial epiphysis (last portion to close)
  • Triplane fracture – Salter-Harris IV fracture in sagittal, transverse and coronal planes

Tillaux fracture

Triplane fracture

• Transverse through physis
• Coronal through posterior metaphysis
• Sagittal within epiphysis and extending to joint

• Salter-Harris I distal fibular fractures are the most common ankle fractures and are often misdiagnosed as ankle sprains
  • Tenderness directly over lateral malleolus rather than at lateral ligaments
  • Diagnose clinically and treat as fracture (Weber B)
• If tillaux or triplane suspected, discuss with ortho re: CT
• Attempt to gain anatomic reduction in all cases
  • If not anatomical, d/w Ortho

Management

• Isolated undisplaced distal fibula physeal (SH I or II)
  • No reduction required
  • Below knee cast, NWB
• Undisplaced distal tibial physeal
  • Above knee cast, NWB
  • Discuss SH III and IV with Ortho re: CT to confirm actually not displaced
• Displaced tibial physeal
  • Above knee cast, NWB following closed reduction
  • Ortho consult for SH III or IV
• Tillaux and triplane <2mm displaced
  • Above knee cast, NWB and d/w Ortho re: CT to confirm truly not displaced
• Tillaux and triplane >2mm displaced
  • Typically require operative intervention. Consult ortho

Last Updated on November 10, 2021 by Andrew Crofton