Just turned 45 and I'm in a similar situation to all of you in that I have OA in my knee due to injury/surgery/years of abuse. I first tore my lateral meniscus (first diagnosed tear but i'm sure there were others) in 2005 and it was an 80% "bucket handle" tear that flipped up and locked in the knee joint. There was no other option but to remove the damaged tissue. I came back good as new and resumed all normal activities for a good 6-8 years, but then started having locking issues again. My knee would lock up, but i could extend my knee a certain way and it would "unlock" and I'd be sore, but fine. Then one night while playing ball, it locked up and I couldn't get it unlocked. I figured that i had torn my meniscus again and made an appointment with the doc.
My personal doctor did some tests and said it sounded like a torn meniscus and referred me to and ortho. He also did the usual tests and sad the same thing and took x-rays. After getting the x-rays back, he said "we can rule out torn meniscus, because you have no meniscus left"
The MRI showd multiple fragments of meniscus and bone chips floating around in my knee that would lock in the joint from time to time causing my knee to lock up. Scheduled "clean up" surgery.
Had scope to clean out the knee joint of everything that was messed up which resulted in a meniscotomy which meant that now i was bone on bone during any kind of impact activites. I wore a regular neoprene knee brace to alleviate some of the pain, but a year later i got fitted for an unloader brace. It was a life saver. I have the rebel reliever from Townsend. It is very big and bulky, but very functional for playing softball. I got it middle of the season last year when i could barely run to first and by the Fall, i was playing center field in a three man outfield.
Basically, i know that i will need total knee replacement sooner rather than later, but the knee brace has helped me to keep playing ball and prolong the inevitable.