[I retired from it a few years ago after over 35 years of military/sport jumping with a little over 7000 jumps.]
For which your back specialist no doubt congratulated you on this long overdue but nonetheless welcome solicitude for your vertebrae.
My hardest landings were in the very days days of military jumping. Round parachutes dont 'flare' for landing like ram-air 'square' parachutes do. So the wear and tear on the body is not that bad, typically. I was an instructor and Tandem master as well, and about 2000 of those 7000 jumps were carrying tandem passengers. That does take a toll on your body, mostly shoulders and back.
So yes, my retirement was partly a decision that my body was done with it and needed a rest. I remain engaged with the sport as a pilot, which is considerably less physically demanding.