It looks like an injury to me. There may be some early scaly leg mites going on. I would flush the wound, use veterycin or a chlorhexidine (hibiclens) or just plain, mild soapy water. Then you can apply plain neosporin to the cut area. Once it's healing you can treat for the mites. Most commonly the legs and feet are slathered in vegetable oil, I like castor oil because it's quite thick, but any kind will do, and then cover with vaseline. It's mess and dirt will stick, but the idea is to smother the mites. You can also use Nu stock ointment.
You will need to apply several times a week, until the legs start to look better.
More info on scaly leg mites here:
https://the-chicken-chick.com/scaly-leg-mites-in-chickens/