Epidemiology
- Uncommon physeal injury, mostly in adolescents
- Salter-Harris II is the most frequent type
Anatomy
- Physis is undulating with mammillary processes interlocking with the metaphysis
- Undulation means displacement shears across multiple growth zones
- Distal femoral physis provides about 70% of femoral length and 40% of limb length
Aetiology
- High energy injury in adolescents, such as sport or vehicle trauma
- Birth injury or minor trauma in infants
Classification
- Salter-Harris types I to V
- Direction of displacement guides risk
Clinical Features
- Swollen tender distal thigh and knee
- Anteriorly displaced (hyperextension) fractures carry a high rate of vascular compromise
- Check distal pulses and peroneal nerve function
Investigations
- AP and lateral radiographs
- Stress views are not recommended
- CT for intra-articular extension in types III and IV
- ABI or CT angiography if pulses are abnormal
Management
- Undisplaced fractures treated in a long leg cast
- Displaced fractures need closed reduction under GA
- Fix with smooth crossed K wires, avoiding the joint to reduce septic arthritis risk
- Metaphyseal screws parallel to the physis for a large Thurston-Holland fragment
- Types III and IV need anatomic reduction and screws parallel to the physis
- Vascular repair if perfusion is not restored after reduction
Complications
- Growth disturbance in about half of cases, even with type II injuries
- Limb length discrepancy
- Angular deformity from partial physeal arrest
- Popliteal artery injury and compartment syndrome
- Loss of reduction
- Follow until skeletal maturity with long leg films
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.