I am a heavy equipment mechanic, and have wrenched for over 15 years. Leaning over the hood of engine, lifting heavy things into awkward spots, etc. My doctor said a mechanics back typically ages twice as fast.
It seems hit and miss, some people who had fusions say they will never heal and still in pain. Some people say they wish they did it sooner. I just need to find relief so I can get back to work, I am not a person who enjoys sitting at home getting paid