Radiology of Note
The distal femoral epiphyses are normally present from birth to 18 -20 years
The patella ossifies between 3 - 6 years
Support the leg with the hip and knee slightly flexed
Analgesia (intra-nasal very likely to be helpful)
Most sources agree that splinting should be carried out as soon as possible, although practically this can be difficult.
< 3months: Pavlick harness
>3 months/ 16kg: Gallows traction
> 16kg: Thomas splint (skin traction)
I have written a presentation that says all this with pretty pictures.
Emergency Care of Minor Trauma in Children. Ffion Davies et al.
ABC of Emergency Radiology