Do you know which type of CMC surgery you will be having? There are several choices including the traditional - using tendon tissue, and suspension, or "tightrope" surgery, and few other less common ones. I have had the "tightrope" surgery on both thumbs, the first one more than 10 years ago, and I highly recommend it for healing time, flexibility and grip strength. I am able to do so much without pain now - sew, quilt, garden, paint (both walls and watercolor), use hand tools, and I seldom drop things now.
Do you have arthritis in other joints as well?