Diseased Bird: House Finch with an injured leg

This house finch has been seen many times in our backyard this year (2020) since the late summer. It was first seen with its right leg injured – the lower part of the leg was dangling from the joint. It now has a stump where this lower part of the leg must have come off. This finch still visits our feeder and can be seen with the other house finches. It seems healthy despite its missing leg.