When something gets "worn through", it gets thinner and thinner through use, until there's a hole in it.

You can use "wear through" in these ways:

• (someone) wears through (something)

  I wear through shoes quickly.

• (something) wears through (something)

  The heel of my boot wore through my sock.

• (somthing) is/gets worn through

  It's already worn through.

Use "wear through" mostly to talk about clothes or the soles of a person's shoes. The "sole" is the bottom of the shoe, which touches the ground when you walk.