If your physician is talking about surgery than I assume you have osteoarthritis. That's causes by the normal wear and tear on joints (especially among people who are overweight) as opposed to rhumeutoid arthritis which is an auto-immune diseases that increases inflammation in the joints. Both are painful.
There are a few suggestions, and there is some good information on the website of the National Arthritis Foundation - www.arthritis.org. Omega-3 fatty acids (the kind in seafood and flax seed) are anti-iflammatory agents and are being studied for arthritis. Eating seafood several times per week or taking a fish oil capsule each day might help. Because saturated fat (animal products are mostly saturated fat) creates inflammation, it's a good idea to eat smaller portions.
If you take a calcium supplement, in addition to the multi vitamin recommended by alli, be sure it also contains vitamin D. Vitamin D is currently being studied for arthritis relief as well. There is confliciting evidence about glucosamine and chrondritin supplements. However, many people I know, and some physicians, say that this can provide relief from osteoarthritis.
There really are no arthritis diet, per se. You might want to see a registered dietitian for an assessment of your current diet, and for ways to incorporate some of what I mentioned above. And you can seek another opinion from an orthopedic doctor.
I hope this helps.
Pat Baird, MA, RD, registered dietitian