Personally, I found the older we get, the more difficult the recovery. While I respect your hesitancy to move forward,
if you are that active at 81, you’d better get it done now. By the way, 8 weeks is also a bit of a misnomer. Everyone is different, but, I’d say 8-weeks at the very earliest. Don’t be discouraged if it’s longer.
Been there twice now, just doesn’t work that way.
Vince

I am 73 and was in similar situation as you. No pain, but instability and knee bowing out. Surgery was on Jan 3, 2023. 10 days after surgery i swore i would NEVER do surgery again. Knee was very very stiff and swollen and it hurt. Hard to go from No pain to pain and stiffness. And the surgery was hard on my whole body. And I am healthy and take no medications etc.
Now 23 days after surgery my range of motion is 120 degrees, pain is when i am stretching and strengthening. I am walking without a cane and can go up and down steps.
I am thinking i may do second knee but waiting to see how my total outcome is on first. Hope this helps.

I was not able to say my TKR was successful until 20 weeks. I am now at 22.5 weeks and although there is no pain when inactive, I still feel stiff at times and sore when I go to gym more than 2 consecutive days. Having said that, I KNOW my left knee is stable and strong now. I have to slow it down because I need the right knee done and it can’t keep up. I swim (walk) 3-4 days per week and walk track/ride bike at gym 1-2 days. I have heard that the older you are the easier it is to recover as there is less muscle mass. Regardless, I’ve had multiple ortho surgeries and can honestly say it takes a full year to feel ‘new normal’. I will definitely have my right knee done.
I am 64.

Hi!
From what I read you say; I would choose not to get it replaced. I am 67 and had successful TKR. I didn’t wait as I could have ( was not in severe pain, had some success with gel shots), but I did it because I knew the recovery was a year and did not want to wait until I was older. I did the pre surgery exercises, PT after and finally after 4 months was out of pain. At 5 months I have times where my knee is stiff , and just uncomfortable. I rode my exercise bike every day and do 20 min. of exercise also.
Walking and golf I look forward to soon. If you are comfortable enough and can do what you want in your day to day; I would not put my body through this at 81. Just my opinion

Plan on a full year to recover. I am 6 months post TKA and doing well but still not 100%.