There are a million things that can cause a knee to hurt. Age is one of the most obvious. As you age, your tissues get weaker and your muscles aren’t as strong. So you could have normal structure, but your knees can hurt for that reason.
Most of the people we see, we can identify something [that caused their knee pain], whether it was an injury from playing sports in high school or just chronic use, from playing tennis for example, as you get older. There are a myriad of reasons.
People who are able to continue jogging and do so successfully into their 50s and 60s may be privileged. In other words, they don’t hurt.
People who hurt when they run, stop running or they should. But people who can run as they get older and older probably don’t have the predisposition to get injuries. However, the 40-to-50-year-old group that still wants to be active and run, they always come and say, “You know I hurt when I run now, and it never used to be that way.” And that’s usually because they’ve injured something or they’re starting to wear things out.
Not everyone can be a successful runner into middle age. But those who are, are probably protected from injury.
Osteoarthritis is deterioration of the structures of the joint.
Most of the knee is made up of bony structure, but at the end of the bones is a thin layer of cartilage, and that’s the first thing that goes bad with arthritis.
Additionally, we have these gaskets or menisci, and they’re very commonly injured as you get older because they age just like the rest of you ages and they become weaker. So a small thing like playing tennis can lead to an injury of the meniscus. Once something like that happens, the cascade or the events that lead to arthritis are much more likely to occur at a quicker rate. Younger people, they have healthy tissues. Older people have older tissues and are more likely to have an injury that leads down this path.
We want people to have healthy lifestyles. One of the leading causes of arthritis is obesity. So, you try to get people to exercise or be active within their envelope of function. If you’re 55 and your knees hurt and you’ve got arthritis, then you shouldn’t be out trying to jog and run marathons. Go to the gym and do some low-impact exercises.
There is some evidence that diet helps. Inflammatory foods might make your arthritis hurt more. But those are things that people can do on their own. When they come to the doctor, they’re looking for more aggressive treatments, not just advice to change your lifestyle. So, we have everything from physical therapy, which is essentially professionally directed exercise program, to medicines.
The standard for medicines is the stuff you buy over the counter — the anti-inflammatory medicines. Those are ubiquitous. They’re effective, but they’re also dangerous. A pill only lasts a few hours. You get a few hours of relief for a chronic condition when you take pills, and that might be enough for the weekend warrior who wants to play golf or play tennis. Pop a pill before and after, but it’s not really a good long-term solution. But unfortunately, that’s what most people do.
Next step would be injections, and that’s a little more invasive. We have anti-inflammatories, such as cortisone. It’s very safe and is injected into the knee joint. They can be effective for months, but again they wear off and they don’t treat the underlying cause. You’re just treating the symptoms while the disease slowly progresses.
It’s amazing how different people are. Some people will hurt their knee on Friday and be knocking on the doctor’s door on Monday morning. Other people will wait years and years because they don’t want to get into a medical situation. They come in and they’re already crippled. And you go, “Why did you wait so long? ‘Oh I hate going to the doctor, I’m coping, I just quit tennis, I just did this and that.’” There’s a spectrum. People have to decide when they’re ready to have treatment.
When they come to me as a surgeon, the first thing I say is not, “You need surgery.” But if they’ve been through years of medical treatment with pills and shots, I'm going to say “Are you ready for surgery?” I can’t tell people when to come. They usually find their way.
If it’s serious pain and it affects your sleeping or things like that, then that usually means something more serious is going on, and you should probably go within a few weeks of your injury.
If it’s a nagging thing, you might say “Okay enough, enough. I’ve had this for a few months. It didn’t get better like most of my injuries used to.” Then you probably need to go in, get an X-ray, have an evaluation and then get a proper diagnosis.
The most important thing about knee replacement is to understand how durable it is. In the old days, people would say, “Oh it only lasts 10 years. I’m going to live a long time. I don’t want to have another one. So I’ll just suffer from 50 to 70 years old and then have one.” But the technology and the skill of surgeons today make it so that a knee replacement usually will last a lifetime.
If you take someone in their 60s, the overwhelming odds are they are going to live their life out with this one implant, and that’s really amazing. Materials have improved and that’s important for people.
Many doctors will just do a full knee replacement in everyone to get the total job done. But some doctors prefer to do a partial in which we would just replace the one part of the knee that’s damaged, whether it be the inside, the outside or the kneecap. That allows the rest of the structure to be intact. And it results in generally a more normal feeling knee and a more normal-performing knee.
In most tests, people with a partial knee and a full knee prefer the partial knee because it feels more like them.
All things being equal, knee replacement is a safe procedure. But recovery is so individualized. It has to do more with the intrinsic nature of a person than the actual operation.
People are also very, very concerned about the mystery of surgery. They’re so afraid of someone putting them to sleep and cutting them open. But there have been advances in anesthesia and postoperative pain management and quicker rehabilitation. You can have a knee replacement and never go in the hospital. Just come and have it done as an outpatient procedure and go home.
In some cases, you would stay in the hospital. It depends on the health of the patient. It depends on the system the doctor has in place. I feel more comfortable having my patients stay overnight so I can see them and make sure my therapists see them first to get them going and make sure their transition home is easy.
We want people to be as healthy as they can be coming into surgery. You have young people who are fit as can be. They don’t have a problem. Or you have older people who are on heart medications or other things, and we want their doctors to make sure they’re as healthy as they can be. Bad things can happen in surgery. That’s what makes people fearful. That said, statistically, it’s interesting to note the most dangerous thing a person does on the day of their surgery is drive to the hospital.
Patients can start walking within hours of surgery. If a person has surgery in the morning and they go up to the floor, the therapist will see them within an hour or two.
When I first trained 20 years ago, they would lay in bed for three days and stay in the hospital for a week. You were so afraid. And now we realize that people do better if they get up and go. Everyone knows that lying in bed isn’t good for you.
The advantage of getting up and walking right away on the new knee is that all the other parts of your body, your lungs and everything else works better. Your muscles don’t get atrophied and people’s expectations are changed. Instead of the fear and, “Oh this is going to be painful and I'm going to be crippled,” they get up and they realize, “Wow, I can walk almost as good, if not better than I did when I came in the hospital.” The mindset changes the whole recovery. It’s pretty remarkable.
Everybody is different. A younger active person can rehab faster. I tell people essentially give me a month. Don’t plan any major travel abroad. Don’t think you’re going to go play tennis and go to the gym. Stay at home and don’t go to work and sit at your office desk for eight hours a day and forget to do your exercises. We tell people don’t drive for three or four weeks.
Most surgeons who do a lot of knee replacement don’t generally tell their patients what they can or can’t do. That said, there’s a list of higher risk and lower risk sports.
But why have the surgery, if you can’t go back to things you like? High-functioning people who have knee replacement maintain that level of function. They don’t get better. I don’t turn a weekend tennis player into a marathon runner. That’s unrealistic. But people who are inactive because of their pain generally lift their activity up. “Oh, I can go back to golf. I can go back to tennis. And I haven’t skied in years. Maybe I want to do that.”
I don’t want it to sound like it’s a perfect joint. It is an artificial joint. It doesn’t work exactly like your joint. It doesn’t feel exactly like your joint. And there are some things that are compromised. But compared to what you had before it’s a tremendous improvement.
For one person, the first sign of arthritis might be that they tear their meniscus, and that starts this cascade of events leading to degeneration of all the other tissues. The next person might have already had wear and tear of the cartilage on the end of the bone and that causes a tear of the meniscus. When you get older, let’s just say over 40, and you have a meniscus tear, the first thing that I’m going to look for is to see if you have associated arthritis with that.
PRP is the acronym for platelet enriched plasma. It is basically your blood, which is full of platelets. Platelets are what help you clot and they have a lot of growth factors in them.
What’s done is your blood is removed and the platelets are separated and concentrated to four to ten times higher level. Then that platelet is injected into an arthritic joint or to a damaged tendon. The idea is you’re concentrating healing growth factors into this area. That’s been studied pretty well in arthritis and in knee joints, and it appears to be pretty effective, maybe not any more effective or durable than some of the other injections. But the important thing to understand is we can’t prove that it heals. That’s what most people think, that the platelets or even the stem cells when injected will heal. But there’s no evidence that that occurs. But it does show is that it can decrease inflammation, maybe stabilize things and provide people extended relief that they’re not getting for other reasons.
Rehab is everything. Your quadriceps are the key.
I simply tell most people, “Can you just get a stationary bike and put it in front of the TV and ride it for 15 minutes a day?” That’s maybe all you need to do and it make a tremendous difference. If you want a good outcome, you have to do the work. It’s not just a miracle surgery and it’s over.
One way to define success is from a surgeon’s standpoint is how long will the knee last? There’s a term we use for that called survivorship.
The failure rate of a knee replacement, where another operation is required, is probably now down to about half a percent a year. That means that after 20 years, 80 percent to 90 percent of people will still have their knee replacement working well. That’s a tremendous number. Another way to measure success is measuring function and what they can do.
There is finally patient satisfaction. This is what my job is in terms of customer service. I want you to be happy with what I did. So we ask patients, “How satisfied are you with the knee replacement?” In most studies, 85 to 90 percent of people say they’re satisfied.