So good to hear from you and that it went right, I was praying for you and I don't do that much.
Like all of the other hippies have mentioned, the incision pain is transient, but it is there and has to be dealt with. We all went through it, and although it passes fairly quickly, the best thing for me was to ice, elevate the leg, sleep with a pillow or two under both legs at my knee and take whatever meds are needed.
He'll need to ice consistently for a while, both for the initial surgical healing and for the longer term recuperation of both bones and muscles. He also needs to be active, despite the soreness, as a matter of fact, it's a way to improve and get rid of that soreness. Is he doing physical therapy? I found it critical for my recuperation, especially to deal with the smaller stabilizing muscles. Those are important to get strong before he thinks of going back to sports or any other activity like that. That will happen, but he needs to get himself healed and then strong (healed first, strong second).
He also needs to eat well (I'm sure you have this down), since his body is going to be on the prowl for anything that will help him recuperate. I was on multivitamins and eating up a storm, drinking tons of water, and walking on my crutches all over. Hopefully you've got nice weather so he can do his walking.
Sorry to dump all this on you, I'm just happy to hear of a good outcome. He's already seeing the benefits of not having that pain anymore, now things will just get better every day.