I suspect both my left knee and left hip are in worse shape due to the foot drop on the right foot. That throws off my gait for sureMight want to do it sooner than later if the bad knee is causing extra wear on the hip. My uncle had a congenital problem in his hip, femur shortened when he was very young. One leg shorter than the other such that he had special shoes made with a 3" sole (think platform shoe ). Walked on his toes if he wasn't wearing those shoes. Had a knee replacement some years ago on the OPPOSITE leg, the short leg limp caused it to wear abnormally.