Salter-Harris I fractures are physeal injuries without epiphyseal or metaphyseal extension.
In the distal fibula, these fractures are classified as 43f-E/1.1.
Displaced Salter-Harris I fractures are rare.
Undisplaced fractures are common, not visible on an x-ray, and diagnosed clinically by local tenderness.
These fractures are more common before the physis starts to close and occur in older children and young adolescents.
Salter-Harris II fractures are physeal injuries with metaphyseal extension. This metaphyseal component is known as the Thurstan Holland fragment and remains attached to the epiphysis.
In the distal fibula, these fractures are classified as 43f-E/2.1.
The Salter-Harris II fracture is the most common pattern of injury involving the distal fibular physis.
X-rays showing a Salter-Harris II fracture of the fibula in a 9-year-old patient