For the plaintiff's lawyer, a lot of the work required for the deposition of a treating physician takes place just before the deposition begins. I'm always surprised by lawyers who do not take advantage of the opportunity to meet with the doctor before the deposition. Even before routine depositions, you should call ahead and say you'll need ten minutes with the doctor. Then prove to him what a nice guy (or gal) you are. If the other side noticed the deposition, tell him the deposition was the other side's idea. Make sure he knows how to get paid for his time. Tell him you hope the deposition won't take very long, but you can't control what the other side will do.
Of course, you should also discuss the more substantive aspects of the doctor's treatment and possible testimony. Some lawyers don’t like to meet with the doctor because they know the conversation isn't privileged, and they think the defense lawyer might learn damaging information by asking questions about the meeting. Always end your meeting with the doctor by telling him that the defense lawyer is entitled to ask what you talked about; if asked, the doctor should answer the questions fully and truthfully. Then let the defense lawyer ask away. I recently had the misfortune, due to my involvement in some specialized litigation, of participating in over a hundred depositions of treating physicians. I can’t remember an instance in which my opposing counsel learned much of value by asking questions about my pre-deposition meeting with the doctor. This might be due to the fact that the defense lawyer also wants to appear to be a “nice guy” and doesn’t want to anger the doctor by bullying him into recounting every aspect of the meeting. Even if the doctor does give a detailed recitation of your meeting, it doesn’t matter, since you’ve prepared the doctor (who hopefully is biased in favor of his patient anyway) to answer these questions in the best light possible.
In summary, use the pre-deposition meeting with the treating doctor to find out where the doctor helps or hurts your case, and to preview his answers to questions he might get from either side during the deposition. Just remember not to say anything to the doctor you wouldn’t want becoming part of his testimony.