The Number One, most important, thing you need to do when you return to running is to get a pair of Hoka One One running shoes. Preferably the Bondi or the Stinsen, they are the most cushioned models. These were introduced to us by Hip-n-hop, our old buddy who went on to complete Ironman less than a year after his second resurfacing. The make every run feel like you are running on a pine needle covered trail.
Second rule: stay off of he roads for training for the first year. Run on a trail, grass , running track or any other soft surface. Give your new joint and the muscles and tendons some extra time to recovery from the surgery. If you want to race on the road OK, but do you training on a soft surface.
Don't be in a rush, but don't be too cautious. It's a marathon not a sprint.
I'm now at around 4.5 years from bilateral surgery. I started running at 6 months but didn't race until one year. I've been on a role ever since. I'll be running a very hilly 15k road rae next month expecting to take an award in my age group, racing the toughest trail run and road bike duathlon in the country expecting the same in May and running the Big Sur Trail Half-Marathon in September hoping to finish in the money.
Once you recover, there are no limits on what you can do!