Often, pain in one set of joints, like your hips or knees, alters your gait to the point that it puts stress on other joints - knees, ankles, feet, lower back
, etc. So if you had some kind of slight congenital deformity in your hip that went undiagnosed, over the the damage transmits to other joints.
First of all, joint replacement is not as uncommon for folks our age as it used to be. I had my first hip replaced at age 37, the second at 40.