Exercise Options Post Surgery

I am almost 60 years old and had surgery to correct a hammer toe in January.  I had the same surgery twenty years ago and it did not take very long to heal completely.  This time, however, they had to put a pin in my toe.  The pin was removed after 8 weeks, and my toe is healing.  However, I still cannot do any hard core cardio exercise including long walks.  I attempted to do a two mile walk earlier in the week, and ended up with a swollen ankle which I have kept iced on and off for the past few days.  Does anyone have any suggestions on exercise I could do in the interim until my foot heals?