The Boston Marathon is every runner's dream, including mine

“If I want to run one last marathon,” I asked, “should I do it before or after a knee replacement?” My orthopedist was leaning over my swollen right knee, shooting it full of cortisone. I’m not new to marathoning — I’ve run five — but my last was more than 20 years ago. I stopped running regularly when arthritis began eating away my knees, and haven’t run more than an occasional 5K in a decade. But I’m 53 years old, and all sorts of doors are closing. I’m not having...