Same thing with an old hen I had. I put antibiotc lotion on it. She was in shock and I fed her with an eye dropper for 2 weeks. After that time, she was able to eat on her own. Another week and I penned her alone on dirt so she could scratch and gain strength. I put a low roost in so she could just hop up. She fully recovered, layed eggs, hatched many more chicks, and lived til a coon stole her head. Yours should be fine.
Oh yeah, since jody added that, I thought I better say my hens bone was also sticking out. Didn`t seem to cause any problems. She mated and lived a normal life.