Sorry to hear about not matching into ortho. Past few years its been one of the toughest field to get into and extremely qualified students sacrifice their career by investing time into it. In terms of what you can do as a surgical intern, unfortunately you will be so busy during the year it will make it very difficult to do anything (especially research) in order to improve your application. The most important thing is making sure you have ortho rotations early on and to work your butt off! (e.g. come in super early, stay late, stay extra in the OR, working hard to know all the attendings etc.). Advantage of prelim year, is you have a lot more responsibilities than a 4th year SubI and its so much easier to stand out and impress your attendings. If you can outshine the ortho interns, that you are a shoo-in for a residency spot in that program (assuming you are doing your prelim where they do have ortho residency). Downside is due to competitive nature its going to be very difficult for you to make up any other weaknesses in your application (lack of publications, low step score, lack of honors etc.).
It is unrealistic that you will get any research project started let alone complete during your busy intern year unless you have a month or two off for research. In terms of following ortho inpatients and helping in clinic you are only able to do them while you are on a ortho rotation. It is impossible to do during any other rotations and you won't be allowed to anyway. Your best shot like I mentioned above is to have early ortho rotations and work your butt off!
There are multiple ways of doing it whether you meet with him before start of intern year or after you have done an ortho rotation. I would prefer doing it after an ortho rotation, because if you have done really well, word spreads around really fast and when you meet him he would already be impressed at the amount of work you have put into the rotation. In terms of things to talk to him about, consider it like an interview and explain your situation and why you feel like you failed the first time and what you are doing to improve it. Share with him programs you are applying to and advice on what your chances are. So from this encounter they will have a sense on who you are and you are already increasing your chances of matching in their program, the more they get to know you.
Overall, good luck with the process, It is tough, probably the toughest moment of your life. I had many prelims in my program you have tried and most failed. A lucky few were successful. The key is to keep your eyes open on forums like this. Most that are successful tend to find PGY2 spots when someone drops out and if your intern year has enough ortho rotations, you will qualify for those programs.
Also the MOST IMPORTANT THING is to not apply to ONLY ORTHO. Like I said most will fail and you DEF dont want to be in a position with no job after prelim year. This is a huge disadvantage due to the following reasons: 1) You are losing another year 2) Medicare will only pay for 5 years of your residency, so the more years you do prelim the more burden it will place on the program you match since the department will have to fund the remaining years. In addition, mention to no one that you are applying for multiple specialties. Dont sacrifice all that you worked for just for one specialty.
Most common specialties that people co-apply for with ortho tends to be general surgery. Many opt for plastics-->hand pathway since many interested in ortho tend to be interested in hand. Anesthesia and Radiology are other specialties people co-apply since they are advance positions so you don't have to repeat your intern year and lifestyle is great. I would try to go to at least 8-10 total interviews during your intern year in order to make sure you have a job after you have completed your intern year.
Good luck!