Cracked rib?

Okay . . . when I got home from work, hubby announces that he thinks he cracked a rib coughing today.   I know he has osteopenia from the prednisone he has to take, but is this even possible???  He insists he's done it before.  This doesn't make sense to me.   Mind you, he doesn't want to be seen by anybody.  Should I believe him?  Don't know what to think.  He also forgot to call about getting his anti-anxiety meds refilled.  Oh happy day . . . :-(