Patching and Plastering - Fixing interior corners

My house is 7 years old with textured interior walls. Ever since we've moved in the corners were brittle. Now after seven years all the corners in the house look like hell. The plaster they put on the corners was thick and choppy to begin with and through the years of bumping and knocking most of the plaster is gone.

What is the best way to repair these corners? I bought plaster from the local big box hardware store but it either a) doesn't stick or b) looks like huge patch jobs against the textured walls.

Are your walls a plaster veneer or just drywall with a texture applied?
I don't know much about plaster but with drywall you would mud the repairs and then texture them to make them blend.

They are drywall with texture applied.

You want to use joint compound for the repairs, texture too.
What type of texture is on the wall?

Not sure about the texture. How do you know or tell?

Can you post a pic of the texture using a free site like photobucket.com?

There are many different wall textures, orange peel and knock down are the 2 most common.