Ok to eat bird with leg problem?

Hello everyone, we noticed yesterday that two of our birds have become somewhat lame. One still gets around, but is limping badly (to me his leg looks dislocated, but I'm not sure) the other one can almost not move at all. She won't stand up, but I've seen hers age to shuffle herself over to the feeder. Never noticed any problems prior to this. All the birds are destined to be processed within a few weeks, but we thought we would butcher these two now since they may be in pain.
I was told by a relative not to eat them as they may have infection/inflammation and to just dispose of them. This is our first year with chix and I'm not sure what to do, but it seems like a waste to her rid of them for just having a leg problem. What is your experience/perspective? Thanks in advance!!