This is a very common type of damage, and the only possible repair is to re-wrap the broken part with high-strength carbon fibre.
The repair is secure and visually appealing. In the photos, you can see the broken dropout and the repaired dropout. The frame still needs to be painted to restore its original appearance.
Gallery
forcellino spezzato
forcellino spezzato lato esterno
forcellino fasciato riparazione grezza
lato interno del forcellino fasciato