My ankles went though hell and back in the 10 years i rode trials, I broke each one 3 times. I have 2 plates and 6 pins in the left and 3 plates and 8 pins in the right. After the last time, I was told there's a chance I may never walk again if i break one of my feet again, so I stopped riding for a good while and underwent some serious physio for both ankles and did alot of strength training, after that i wore ankle braces on both ankles for 12 months or so when i got back on a bike and I never really had much trouble. I've been off a bike for 3 years now, getting back on one again next year, I imagine they should be fine still. I do alot of running and training day to day anyways.
Also, out of curiosity, Hows your weight and build? Being overweight plays hell on the joints, especially after any damage and also at an older age. So if your carrying a little more weight than you should be, hit the gym or some high intensity circuit training and improve your fitness and weight. I also found drinking alot of milk to increase bone strength and also eating high protein foods to strengthen muscles.
This is as much a sport as any and Physique and diet are just as important than that of a Boxer or Football player.
If you really want some professional help, there's a guy on here (If he still uses the forum) called Si the Physio, He's dealt with myself and alot of big name riders in the past to help them through injuries etc.