Total knee replacement is rapidly becoming one of the most commonly performed procedures in the field of orthopedic surgery. An estimated 4.7 million Americans have undergone total knee replacement and are living with implants. For perspective, there are approximately 1.5 times more people living the United States with a knee or hip replacement as there are people living with heart failure. The most common indication for knee replacement is debilitating joint pain from underlying osteoarthritis. Osteoarthritis develops when cartilage (the “cushion” in the joint) wears away, which can eventually result in bones rubbing against one another. This can lead to debilitating joint pain and stiffness. If nonsurgical treatments, such as anti-inflammatory medications, physical therapy, and joint injections, do not provide adequate pain relief, joint replacement may be a viable option.
Certainly, the goal of knee replacement is improvement in pain and joint function. In my opinion, knee replacement may represent an opportunity to lead a more active and healthy lifestyle. Joint replacement, however, will not allow you to do more than you could before you developed arthritis.
This leads to an essential question by a prospective knee replacement candidate: “What can I do after surgery, and what should I avoid?”
In the early postoperative period, I generally recommend up to 30 minutes of exercise 2 to 3 times per day. This consists primarily of range of motion and strengthening exercises. In addition, walking as tolerated is encouraged to promote knee function.
As your pain and function steadily improve, I encourage incorporating low-impact activities, such as gentle yoga, swimming (once the surgical wound is fully healed), cycling, or using an elliptical machine. These activities promote motion and strengthening without placing undo stress on the implants. Recreational activities, such as dancing, golf, doubles tennis, and rowing, can also be introduced as tolerated.
It is important to recognize that a knee replacement may develop some wear in its plastic cushion with normal use. Excessive high-impact activity or body weight may place extra stresses on the implant and lead to early failure. This could result in the need for further surgery. For this reason, I recommend avoiding high-impact activities, such as running or jumping. With appropriate activity modification, knee replacements can be long-lasting. Currently, more than 90% of modern joint replacements are still functioning well for 15 years after surgery.
Before considering knee replacement, I recommend discussing postoperative goals with your surgeon. Having a realistic understanding of what a joint replacement can and cannot do is essential to having an optimal postoperative outcome.