Bad leg - injury at joint?

[HeidiGretchen]

Brought this chick home just now to try and help it. What's going on with its leg? It holds it out to the side, never putting weight on it, and te foot appears to be turned a bit sideways. It hops around on the other leg. When my husband found it at the feed store, it had no water and terrible pasty butt.

We've cleaned the past butt and given chick starter and water with nutridrench. She's been chirping a ton, and is just now resting under the heat lamp.

She's a silver laced wyandotte, probably 1 week old.
How can I help her?

 

[HeidiGretchen]

Updating - I noticed her leg joint felt really large, so I gently washed it and it appears swollen and possibly raw. She doesn't fuss if I straighten it or pull her leg back like when a chick stretches. But still holds it up constantly and hops around.