People I know who played back in the 60s and 70s invariably have issues with hips and knees etc. I always thought it was just a feature of having played a contact sport on a regular basis.
For modern players, I wonder if this is in part a by product of increased use of supplements to enhance training. It's just a thought. With legal supplements one would assume the use is safe, but longer term use would surely have some consequences. Certainly with illegal supplements e.g. steroids there is an increase in conditions such as osteoporosis.