Wow! My 75+ neighbor fell snd had to have hip surgery (the ball was fine, no arthritis, but the part below the ball was replaced. - she has been recovering for weeks and weeks, and has had no setbacks, and is in good health, but took awhile!My down the road neighbor had a hip replaced last Thursday. It's a new method of replacement, and she was home the same day, walking around the property with the roller walker for three days, then without since then, and today, I saw her driving herself out of the neighborhood! OMG! Amazing.