Doctor Thomas P. Sculco, Surgeon-in-Chief at the Hospital for Special Surgery in New York, notes how hip replacements last much longer than patients expect them to.

About 90% of patients are going to be doing well with that implant in twenty years. The last important thing that patients always ask me, and I think is important to discuss and patients want to know is, "I'm going to have a hip replacement, I'm fifty years old, what's the life-expectancy of this implant?" And the good news is that you can pretty assuredly tell patients that ten years from the operation, 95-97% of these hips are performing well. And if you take these numbers and extrapolate them out to twenty years about 90% of patients are going to be doing well with that implant in twenty years, so the numbers are quite good.