Background
During adolescence, the distal tibial physis closes asymmetrically. This creates characteristic transitional fracture patterns before complete skeletal maturity.
Tillaux fracture
A Tillaux fracture is an anterolateral distal tibial epiphyseal avulsion produced by the anterior inferior tibiofibular ligament during external rotation.
It is essentially a Salter-Harris III pattern.
A Tillaux fracture is an anterolateral distal-tibial epiphyseal avulsion caused by the pull of the anterior-inferior tibiofibular ligament after part of the physis has already closed.
It is intra-articular and corresponds to a transitional Salter-Harris III pattern.
Triplane fracture
A triplane fracture has components in three planes:
- sagittal through epiphysis
- axial through physis
- coronal through metaphysis
The pattern may consist of two, three or more fragments.
A triplane fracture extends in three planes and appears differently on AP and lateral radiographs. It has epiphyseal, physeal and metaphyseal components.
Because the geometry is three-dimensional, plain films can underestimate displacement.
Imaging
Plain radiographs identify the injury, but CT is often used when displacement or articular geometry is uncertain and operative treatment is being considered.
Treatment principle
The goal is restoration of the ankle articular surface and stable healing.
- minimally displaced congruent fractures can be immobilised
- displaced intra-articular fractures require reduction
- percutaneous or open screw fixation is used when reduction cannot be maintained closed
Because remaining growth is limited, the immediate concern is often articular congruity rather than major future limb-length discrepancy, although growth arrest can occur.
Why they occur
During adolescence, the distal tibial physis closes in a predictable sequence rather than all at once. Partial closure creates characteristic transitional fracture patterns.
The two classic injuries are:
- Tillaux fracture
- triplane fracture
CT
CT is useful to:
- define fracture configuration
- quantify articular displacement
- plan screw direction
- confirm adequacy of reduction in selected cases
Treatment
Minimally displaced fractures can often be managed with immobilisation and close follow-up.
Displaced intra-articular fractures require accurate reduction. Closed reduction may be attempted, but residual articular incongruity beyond acceptable limits is an indication for fixation.
Fixation
Screws should be placed to compress the fracture while respecting the remaining physis where relevant and avoiding joint penetration.
Prognosis
Because these injuries occur near skeletal maturity, major growth disturbance is less common than in younger children, but articular incongruity can lead to post-traumatic arthritis.
FRCS synthesis
The key point is that these are intra-articular fractures occurring during asymmetric physeal closure, so CT-defined articular reduction matters more than concern about a small amount of remaining growth.