I was blessed with the arthritis gene! Along with some athletic issues and job related misuses of both hips and knees. Had a total hip replacement when I was 52 years old (will be 74 next month) it would go out on me constantly. I'd be walking along and all of a sudden it felt like I was stabbed with a knife, had to regroup a few minutes before walking again.
Second hip was replaced 10 years later...all good, and frankly should not waited so long. Right about then I purchased a Tri- Glide, thinking that was what I needed. I was correct as then both knees were replaced (about 2 years apart) Now I call them racing stripes...uppers and lowers! All in all it wasn't the worst thing that could happen, and after gaining some confidence, I went back to 2 wheels.
Fast forward to today....both knees and hips are holding up well!! My riding days will be coming to an end soon, however, not due to any knee or hip issues, thankfully. Research as much as you can, and believe me no matter what anyone tells you, it is definitely worth it, and you be saying I shouldn't have waited so long!