Years ago my dad had something like that. There was no way to get into it from the side. He had to back into it and swing his legs around the front bumper to sit down. The bumper was so wide there wasn't much room between the bumper and the tires. I was 40 years younger and I found it awkward getting to the seat to sit down. It looks like the bumper on this one may be removable but then your feet become the bumper
I had both hip joints replaced a few years ago. I'm 79 now, and I don't believe that I would be walking if I hadn't had them done. The recovery time was amazingly short. With both hips, I was walking without a cane after just 3 weeks. With the second (left) hip, I was using a cane to walk up and down a flight of stairs, the day after the surgery.
In retrospect, I wish that I had them done a fer years earlier, instead of putting it off because of fear. These days, I can hike 2 or 3 miles with no hip pain at all
While knee joint replacements usually have a slightly recovery time, they tend to have results that are just as good. Just remember that recovery time will be inversely proportional to how aggressively you attack your rehab.