Well done Nfk Dumpling It's such a scary thing to do! I knew that I would never have the courage to go back & have second knee done that I had them both done together three years ago! Changed my life for ever, thank goodness.
I used a Vaseline intensive care cream on my scars (once healed) and still use cream daily now. My scar split a little bit too, but it was only on the surface and nothing to worry about. My only piece of advice keep doing the exercises even when stiff & split, the more you rest them the stiffer they'll get, and quickly too! Little and often if they are stiff, set little goals and go for it! I found using my bike the single best thing for getting the bend back, it's electric so that helps when I get tired.
My scars are pretty faded now, but I'm proud of them because I'm such a coward and overcame fear to be able to walk again - if mine only last 10 years I'll be happy, don't expect I'll want to do 5+ mile walks when over 70, or maybe I will and still will, after all they won't hurt maybe squeak a bit?
Take care