An interesting thought came to mind, prompted to some extent by my acceptance of the need to get TKR and in part from other threads.
What is pain? OA develops over years, it sneaks up and gradually eats away at our enjoyment of life. As a result there is no specific time when it becomes obvious that it is time for surgical intervention.
When young my pain was sinmple, really. It usually came from injury. First, I was healthy and pain free and then an incident occurs and I would have pain and usually things got fixed and the pain would go away.
As we age, things change, we start getting little aches and problems. We start using words other than "pain" like sore or tight or stiff or swollen. Doctors often use a 10 scale for pain 1 = no pain, 10 is worst ever pain.
OA, for me, seemed like 2-4. Rarely higher. Not so bad, right? Certainly compared to those acute injury events of my youth or a broken bone from a fall, etc.
I also think there has been a tendancy to downgrade the pain because I have become use to it. It's "normal" so i don't think of it as so bad.
That went on for years and slowly but surely my activities became fewer. If an activity caused hurt, I stopped doing it. As a result that pain level was kept at that 2-4 level.
Frankly, if I had not gone on a backpacking trip where every night and after any rest break the pain level went to the 8--9 level, I would not have gone to a doctor and gotten the x-ray which showed both knees were bone-on-bone.
Interestingly, in the past couple weeks, as I finally began to understand that TKR was the only action that makes sense for me. That I seem to be acknowledging more pain, I even use the "p" word now. It "hurts" instead as just being stiff. I don't believe it has gotten worse, I believe I have begun to acknowledge the truth.
I expect there are others who are struggling with the decision, as I am, should consider two things.
Have you knees stopped you from living your life the way you would prefer?
Is your "discomfort" controlled by changing your behavior?
The answer is yes for me.