The short answer: about as much I know about cardiac surgery! 
That’s the problem. In todays’ world, an “expert” in one thing is somehow an expert on things they know very little about.
Recently, Dr. Oz did a program about bunion surgery which most podiatrists felt was biased and frankly not factual. Dr. Oz had a guest who was wearing a cast eight weeks after surgery. The guest then explained how slow and painful her recovery had been. It is unusual for people to be wearing a cast eight weeks after surgery. Podiatrists who perform bunion surgery will also tell you that with modern techniques severe pain after surgery is the exception – not the rule. That is certainly my experience with bunion surgery.
To add insult to injury, Dr. Oz did a demonstration of the most basic type of bunionectomy on a giant model of a foot cutting off the large bunion bump with a two-man crosscut saw. (Like the saws used to cut down giant trees). What a barbaric oversimplification of a delicate, precise and sophisticated surgery!
Today there are many types of bunion procedures. The correct procedure is chosen after a careful examination of a person’s foot, examining their x-rays and evaluating the positions and quality of their bones and joints. We then watch a person’s gait and carefully consider their needs, goals and lifestyle.
Bunion surgery is very sophisticated today and it is not usually very painful.
I’ll bet Dr. Oz knows as little about modern bunion surgery as I know about cardiac surgery. Wouldn’t everyone be better off if we sought advice from people who really know what they’re talking about?