Distal Tibia-Fibula Physeal Fracture
Distal tibia-fibula physeal injuries account for 25% of all physeal injuries.
The distal tibia is the third most common physis to be injured.
Salter-Harris type I distal fibula fractures are the most common ankle fractures. They are often misdiagnosed as an ankle sprain or are missed.
Distal tibial physeal fractures are classified by the Salter-Harris classification.
They can also be classified by the mechanism or direction of force applied to the injured ankle.
Due to the asymmetrical closure of the distal tibial physis during early adolescence, transitional fractures can also occur.
Tillaux fracture – Salter-Harris type III fracture involving avulsion of the anterolateral corner of the distal tibial epiphysis (the last portion of the physis to close)
Triplane fracture – Salter-Harris type IV fracture, which occurs in three planes (sagittal, transverse and coronal).
The patient will present with a painful, swollen ankle.
The foot can be in a deformed position.
The patient will not want to weight bear.
Salter-Harris type I distal fibula fractures are the most common ankle fractures.
They are often misdiagnosed as an ankle sprain or are missed.
Tenderness will be located directly over the lateral malleolus rather than at the lateral ligaments.
Any patient with a significant mechanism of injury should be assessed via Advanced Trauma Life Support (ATLS) principles.
AP, lateral and mortise views of the ankle should be ordered.
If a Tillaux or Triplane fracture is suspected, then the CT scan is ordered.
Undisplaced isolated distal fibula physeal – Salter-Harris type I and II: No reduction is required, treated with a below-knee case, non-weight bearing, and analgesics.
Undisplaced distal tibial physeal injury – No reduction is required, treated with an above-knee cast, non-weight bearing, and analgesics.
Tillaux and Triplane fracture < 2 mm displacement – No reduction is required, treated with an above-knee cast, non-weight bearing, and analgesics.
Operative intervention is indicated:
Displaced distal tibial physeal injury – Unable to achieve or maintain reduction
Tillaux and Triplane fracture > 2 mm displacement
Neurovascular injury with fracture
Extreme swelling/compartment syndrome
The child should remain non-weight bearing until instructed
There is a risk of compartment syndrome with the cast. Provide parents with “Caring for your child in a leg cast” and warning signs of a tight cast: increased pain despite analgesia, change in toes – colour, perfusion, increased swelling. Any concern should prompt an immediate return to the emergency department for evaluation.
The majority of fractures heal well and the outcome is excellent. With any fracture involving the growth plate, there is a risk of growth arrest. With any fracture involving the joint surface, there is a risk of future arthritis in that joint.
Growth arrest (one-third of injuries)
Compartment syndrome/neurovascular injury