Like most Americans, I use the American style.

but you're story about switching due to an injury
got me thinking about a bit of family oddity...
We invariably sat in the same preffered positions
throughout every meal while we still lived at home
but were never "taught" silverware etiquette as such.

It wasn't until 20 years later that my older brother
brought up the fact that although our younger brother
was right-handed in every other way... he invariably
ATE left-handed. His wife said, "Yeah! What's with that?"

Jimmy just smiled and said, as a baby, I learned to eat
by mirroring the person sitting directly across from me
at the table (which was me.) and it became a fixed habit.