Hip and knee replacements are extremely common these days. Through my personal-training experience, I've seen hundreds of cases — both before and after surgery. What surprises me the most is the difference in recovery time between those who had previously exercised regularly and those who were not accustomed to exercise at all.
In most of the cases I have seen, the people who participated in regular exercise prior to surgery had a much faster and less stressful recovery time than those who had been primarily sedentary. Of course, nothing should be done without the consent of your doctor before taking part in an exercise program, especially if you have a joint problem. That being said, I think it would still be very prudent to consider taking advantage of this little-known phenomenon so that the process of getting your joint replacement might be more tolerable and result in a faster recovery experience.
Joint replacements used to have a place in science fiction. Now they are performed daily by some orthopedic surgeons. Even though the process has been almost perfected, it is still a major surgery. The body has to recover from a surgical procedure just like any trauma to the tissues of the body. This is where exercise really begins to play a role. Those who exercise regularly tend to recover faster from injury compared to those the same age who don't. Through exercise, the body can adapt on a number of different levels. The nervous, vascular, lymphatic and muscular systems all work better when the body is conditioned. As a result, the tissues around the joint will receive more blood, have less swelling and more support from the conditioned musculature when recovering from orthopedic surgery.
Strength training is an important part of exercise, especially when it comes to joint pain and function. Our bones are where they are because of the constant and, hopefully, balanced tension our muscles apply to them. When the muscles around a joint are weak, the joint is unable to stabilize well and has to rely on its ligaments to keep things in place, causing wear and tear. It is important to have decent strength in the muscles around these joints in order to keep them healthy. With a hip or knee replacement, strength is extremely important in order to be able to use the joint effectively. This is one of the reasons for physical rehabilitation following surgery. Although the muscles around the joint will be weaker post-surgery, they will recuperate much faster if they were previously conditioned. You could almost say the muscles have a previous "memory" of their strength and are able to retrieve this quicker — hence the notion "muscle memory."