Diagnosis can usually be established on history and examination. If there is a history of a fall or any bruising, swelling or deformity, consider other causes (see Precautions) and refer for plain radiographs.
Manipulating the arm during examination will often reduce the injury.
Expect distress and pain during reduction manoeuvres. This should pass rapidly with the child returning to using the arm without pain within around 5 minutes.
The pronation method might be more effective and less painful.
Manipulation may fail on the first try.
If the reduction fails with both pronation and supination then consider referring for radiographs and reduction under anaesthetic.
Warn parents of possible recurrence (typically within a month).