I had sprained my knee pretty bad in 2017 and the doctor sent me for knee x-ray. She told I had bone on bone in right knee. I hate surgeries, so began walking on treadmill. Now at age 83 my knee is pain free most of the time, unless I over use it, then i wear a knee brace until pain is gone.
Well I wore my knees out hauling freight, lifting way more than I should, jumping in and out of trucks\pushing trailer dollies..Just wore them out. I looked at that craziness of stem cell injections and that would not ever work but a big money getter for many who are afraid of surgery..