Hi there,
My boy has had both his cruciates repaired in the last 7 months...yes both, it sucked! He had the tibial crest transplant surgery rather than regrooving etc.
I noticed with both of his he had a small round area near the knee cap following the surgery which was actually his internal stitches and a bit of swelling/calcification. This cleared up in time (probably about 4-5 weeks) however I would be concerned about the non use of the knee.
My boy was probably fairly different, as he never really held the leg up as such, he weight beared very lightly on his for the first 2 weeks and then it was as if nothing had ever happened. Which wasn't ideal either because he was trying to do far to much!
I would be going back to the vet, my vets opinon to us was that at 8 weeks they should be 100% recovered in terms of walking etc and just need to start regaining muscle tone. I guess it all depends on the surgery type you had done also. I know with the tibial crest transplant they recover quite a bit quicker and there is less chance of any damage being done after surgery because of the pins and screws and all of that wonderful stuff.
Good luck with it, hope it all goes well!