Originally Posted by BlueLightning
I'm guessing the limp Bruce has Rises is because his battle with the Joker and Two-Face final encounter. He was limping in the last scene in TDK. That makes me think that one of the reasons he stopped being Batman was the body damage. Added to that, now he was being hunted by the authorities and later with the creation and passing of the Dent act.
It can go either way. That could very well be the case, or he could have developed arthritis of the knee and his knee could have gotten worse over time. The doc saying he had no cartilage in his knee jives with that, as with osteoarthritis the cartilage gradually wears away. There's also post-traumatic arthritis, which can develop years after the initial injury.