I had one approx. 6 years ago..up & walking 2 hours after I wake up, with a walker, off pain meds, except after a rehab session or occasionally at night in less than 10 days.
3 weeks in, feeling fantastic, crushing rehab, soooooo happy! Rehab's star pupil, "look how hard she works!"
Week 4, increasing pain.
Week 5, barely walking. Worse, far worse, than even before surgery. Had to insist on seeing the doc (obviously I was just a whiner!), in fact they told me he wasn't there that day......PA takes one look at the xray, Runs to get the doc. (i hope you never see a medical professional run!)
The glue fusing the tibia to the lower prosthesis had failed. Possible complications could include internal gangrene & death....no time for healing, immediate surgery needed. (except for the wait for enough time in the OR).
Week 8, back into Major surgery ( about 2x longer than the original, and that was just doing the lower portion...but they opened up everything again to check for gangrene, soundness, etc.....the removal of the first prosthesis is Horrendous work! They replace the new knee with the '"fix" they use after the thing fails after 20+ years. (Where do I go then?)
Recovery, because of tremendous scar tissue and the extensive repair surgery before the thing was even healed isnow ongoing & life-long, major swelling randomly occurs 2-3-4 times a week, after even minor use. And yet I have full range of motion!
If your repair goes well, you will feel better immediately! Those few weeks were the best of my adult life! But there are far more complications & problems then they admit. To this day, no one has even answered why the glue failed!

I had my left knee replaced twenty years ago. They've gone in three times since, two arthroscopic procedures and one revision. Even though I have full movement back, I live on pain medication and have a lot of difficulty with stairs. Now my right knee is going and I'm seriously conflicted about whether or not to have it replaced. I know the technology has advanced tremendously, but.......

May 28 2018 is when I had mine. I'm told a full year is when you can be fully recovery. 6 till 8 weeks until your off of the walker/crutches/cane good luck ?

Here's the man of steel about a week after his second knee replacement.

My Dad has had both his knees replaced, one at 86 years old and the other the following year. He had the second knee done with twilight anesthesia. Each time they had him up and moving around very quickly. I had arranged for a couple of friends to help him get out of the car and up the front steps when he came home from the hospital but he got out of the car and took off without us!

When he came home, he had equipment to use for physical therapy. He would put his leg up on this device that would move his leg in a pedaling-type motion. A physical therapist would come by a few times a week. Each time, I thought his recovery seemed quite rapid. I have his arthritis and he moves faster than I do these days!

A friend of mine who is 37 years younger than my dad seemed to have a more difficult recovery! She says she still has pain a few years after her last surgery.

I have knee replacement in my own future but right now I don't know when!

Good luck...I only had knee arthroscopy...I was walking the next day but still will have about six weeks total recovery...

Go to WorkoutWarriors...there are a few there that talked a lot about their knee surgeries and recovery...

[agnostic.com]