A total knee replacement sounds as if it were a complete solution, like getting a new tire for your car. Unfortunately, surgeons can’t yet make a knee ravaged by arthritis as good as new. And anyone contemplating a total knee replacement, also known as a total knee arthroplasty, should consider its potential risks and limitations as well as its benefits.
“Most people experience pain relief and can move more freely after a total knee arthroplasty,” says John A. Flynn, M.D., M.Ed., medical director of the Spondyloarthritis Center at Johns Hopkins University School of Medicine in Baltimore. “But about one in five patients continues to feel some mild discomfort or have less function than they expected.”
A total knee replacement is considered one of the most successful surgical procedures in medicine. The dissatisfaction among 20 percent of patients may have something to do with their expectations.
Joint replacement is not a quick fix and is not without risk. Serious surgical complications, such as blood clots and infections, can occur. In addition, recovery can be difficult and time-consuming.
However, for tens of thousands of people, the damage osteoarthritis causes is so severe that the only remaining option is a joint replacement. Most individuals who undergo surgery experience less pain as well as significant improvements in psychological well-being and quality of life. The potential rewards for your physical and mental health can be significant.
What do patients expect?
In a December 2015 study in the Journal of the American Academy of Orthopaedic Surgeons, researchers at the University of Pennsylvania identified the top expectations of total knee replacement patients:
• Pain relief
• Improved walking ability
• A return to activites such as sports
In addition, patients were also hoping to see improvements in:
• Psychological well-being
• Sexual activity
• Social interactions
• Employment resumption
The researchers also identified several pre-op risk factors and patient characteristics associated with dissatisfaction after a joint replacement. The factors included mild to moderate arthritis, severe pain during simple range-of-motion movements, a desire to return to high-impact activities, and narcotic use.
Patients who are obese or who have diabetes, pulmonary disease, back pain, or depression may also be less satisfied than healthier patients. Doctors may need to help those patients better manage their expectations.
When is it time?
For many people, it can be difficult to know when it’s appropriate to have knee replacement surgery. You should consider a knee replacement when conservative pain-relief remedies, such as drugs, lifestyle changes, and physical therapy, are no longer adequate. You’re a good candidate for knee replacement if you have:
• Daily pain that’s significant and disabling and interferes with activities of daily living, particularly pain worsened by weight-bearing activity and stair climbing
• Significant knee stiffness, even if morning stiffness and flexibility improve over the course of the day
• Knee instability that causes buckling
• Knee pain that awakens you at night
By this time, you shouldn’t put off knee replacement, Flynn says. “The more time that passes, the more bone and cartilage may be worn away. As the knee loses its natural shape, more complicated surgery will be required to repair it.”
Moreover, it’s optimal to perform knee replacement when you’re in good health. If you delay and develop medical problems later on, surgery may be riskier. If increasing pain keeps you from moving, your muscles will weaken, making rehabilitation more difficult. At the same time, other aspects of aging can put you at greater risk of complications.
What’s expected of you
A total knee replacement doesn’t begin and end with surgery. You, along with your surgeon, play a large role in achieving a successful outcome.
First, you must fully understand what to expect when living with an artificial joint. Prepare by learning as much as you can about the procedure, the recovery time, and the rehabilitation process.
In one study, people who participated in a two-hour educational program before knee replacement showed markedly greater and faster improvement after surgery than people who didn’t participate in the program.
After the procedure, your satisfaction depends on your willingness and motivation to follow your healthcare team’s rehabilitation and care instructions. Below are important considerations to keep in mind:
• You must commit to consistent physical therapy during recovery.
• It can take a year or longer to fully recover—but you should be about 80 percent recovered within the first three months of your procedure as long as you participate in your prescribed rehabilitation. Recovery also depends on your health and condition before surgery.
• Residual pain, stiffness, prosthetic noises (grinding, pops, and clicks), and difficulty with stairs may persist up to two years after surgery.
• Expect to have some bad days during recovery, but don’t let this discourage you; it’s natural, and there will be more good days than bad.
• There’s a chance that not all your pre-op pain will subside after surgery; in some cases, mild pain, though improved, may linger.
• You’ll likely be aware that your new knee doesn’t feel or function like your natural knee. You may also feel some numbness or decreased sensitivity in the knee area.
• You’ll no longer be able to participate in high-impact activities like running.
A successful, satisfactory outcome also depends partly on the experience of the surgeon and hospital. Look for an orthopedic surgeon who performs a reasonable annual volume of knee replacements—50 or more a year. The hospital should be involved in performing at least 200 knee replacements each year.
Highly experienced surgeons and hospitals are also associated with a reduced risk of complications related to surgery.
What to expect during recovery
Your road to recovery starts before surgery. You’ll want to improve your health in every way you can. Exercises to strengthen the muscles around the knee can improve its stability. If you’re overweight, shedding pounds will help since less weight means less stress on the knee. Also, excess flesh can make the surgery more difficult.
But even seemingly unrelated health problems can affect knee surgery. For example, periodontitis, or gum disease, can pose a risk since bacteria from the mouth can travel to the joint, leading to infection.
After your surgery—either on the same day or the next—a physical therapist will begin working with you. As soon as possible, you’ll try to walk, putting as much weight on the leg as you can. But full recovery will take a while. Many people rely on crutches or a walker at first, and then use a cane for a while longer.
Most people can walk well within three to four weeks, but recovery speed depends on your fitness and how diligently you carry out your therapist’s instructions.
The bottom line
Have a frank talk with your orthopedic surgeon about what’s important to you and what you should expect after your knee replacement.
Despite the potential challenges and limitations, most patients are overwhelmingly satisfied with their pain relief and improved function after a total knee replacement. They report huge improvements, escaping pain and disability that limited them for years. Those going in with realistic expectations will very likely come out satisfied.
Laird Harrison writes about science and medicine. His work has appeared magazines (TIME, Audubon, Discover, Men’s Fitness, Health), newspapers (San Francisco Chronicle, Chicago Tribune, Detroit Free Press); and Web sites (Salon, Reuters, MSNBC, CNN.com). He has produced video for Web sites including Smithsonianmag.com and audio for KQED and WUNC public media stations. His recent novel, Fallen Lake, tells the story of a powerful attraction between two couples and how it affected their children. Harrison has taught writing at San Francisco State University, UC Berkeley Extension and Mediabistro. He grew up in Berkeley, California, and studied creative writing and politics at the University of California, Santa Cruz. He lives in Oakland, California.