But we do have an idea of how long a joint replacement will last based on data from past surgeries. During my training in the 1980s and 1990s, the teaching was that up to 90% or more of hip or knee replacements would last at least 10 to 15 years. We still quote similar numbers. But it might be better than that. With better preparation prior to surgery (including "prehab" exercise and loss of excess weight), improved materials in the replacement, better surgical techniques and anesthesia, and better physical rehabilitation after surgery, your joint replacement of the knee or hip is more likely to be successful and last the rest of your life than ever before. At least we hope that's the case.