There are now two ways to do the incision for a hip replacement. The original way, which cuts thru muscles and requires rehab. Or the new way, which misses the muscles and requires no rehab.
My dad had the new way a couple years back. He was 72 at the time, spent 2 nights in the hospital. Never used a walker. Only used the cane for a couple days. No rehab. Was back at work in a week. He literally had more down time with a cold than with the hip replacement.
His twin brother had the old type of surgery, which required rehab and he still has problems with the hip.
Seriously, look for a surgeon who can do the surgery the new way. I think the incision is from the side, not the top. My dads surgeon was a very young guy, who had just done his internship at Johns Hopkins, and had been trained on the new surgery. It was amazing how easy the recovery was. He is now back to walking 10+ miles a day, when he could barely walk to the mailbox before the surgery!