Q&A: Everything You Need to Know About Knee Replacement

Andrew Foster, MD, is an expert in both conventional and robotic knee replacement surgery with Providence Little Company of Mary Medical Center. He leads an active lifestyle, running, surfing and weight training, so he understands and empathizes with patients’ concerns about returning to the sports and activities they love after surgery. Here he discusses what patients considering getting a knee replacement should know.

How does a person know that it’s the right time to have a knee replaced?

If your knee’s bothering you only 30 minutes once a week, it’s probably not the right time. But when you’re thinking about your knee most of the day and it’s keeping you from doing things that you enjoy, like vacations or hobbies or even just basic things like getting up out of a chair, that’s usually when people make the choice to have a replacement. It’s a quality-of-life issue. The decision should be based on how you’re feeling right now.

Is it possible to wait too long for a knee replacement?

Not really. Even in very severe cases where the patient has waited a very long time and has severe deformities, we can correct that. It might just be a little trickier on our end, but that’s why we have the expertise and the cutting-edge medical tools available to us to perform successful procedures.

What’s the difference between a partial and a total knee replacement?

A partial knee replacement involves reconstructing only one of three portions of the knee—the inside (medial) compartment, the outside (lateral) compartment or the patellofemoral joint, which is underneath the kneecap. For example, if a patient has arthritis in only one of those three compartments and the other two are pristine and the knee mechanics are normal, that’s where a partial knee placement can be considered.

Total knee replacement is much more common. For me, the ratio of partial to total is something like 1 to 20 or 30. There are some patients who say, “If I’m going to have one surgery, I want the definitive surgery.” That would be the total knee replacement, which means it’s going to stay intact longer.

How long will a knee implant last?

I tell patients to expect it to last the rest of their lives. At the 20-year mark, there’s a 90% chance it’s still going to be functioning. The manufacturing of implants has gotten much better over the past decade.

What is the most important thing a patient can do to ensure a good outcome?

I’d say it’s keeping a positive attitude. When patients have a positive attitude and realize that they are going to get better—that it just takes some time—those are the patients who do very well. It’s not a quick fix, so it’s easy not to see the light at the end of the tunnel. The ones who get discouraged and get down on themselves or get down in general, I think, are the ones who experience a little more pain and maybe not as good an outcome.

Is there any alternative to knee replacement surgery?

Physical therapy early on can be fairly helpful for restoring the proper knee mechanics and strength around the knee. That can be helpful in relieving pain, along with a combination of anti-inflammatory medications like ibuprofen. The most common way that we treat knee arthritis before surgery is various types of injections, usually starting with corticosteroid injections—what people will refer to as cortisone injections. Platelet-rich plasma (PRP) injections, where we use your own blood proteins to speed healing, are also an option.

Is it better to have both knees replaced at once or do them one at a time?

I try to talk patients out of doing both knees at once. If you’re going to do that, you need to be very healthy going in and have a lot of help at home during recovery. For most people, I recommend that they consider having the second surgery at the earliest six weeks after the first. The best timing is a three-month gap in between.

How important is it to do physical therapy after knee surgery?

It’s imperative! Post-surgery, patients should have physical therapy at least twice a week and follow the home exercise program the physical therapist gives them every day.

The worst-case scenario is if you do nothing you can end up with the knee getting very stiff. When that happens, you’re looking at having to go under anesthesia to have the knee manipulated so that it can move again.

Is it realistic for a patient to expect to recover all function in the knee— that is, to be “as good as new”?

We’re not going to turn back time—you won’t be 20 years old again after surgery. But you should be able to return to most of your previous activities. If you were hiking before, you can get back to hiking. And pickleball, cycling, swimming, surfing and golf are all okay. Jogging across the street or chasing your dog is fine, but the knee implant isn’t made for distance running, so no more marathons.

For more information on Providence Little Company of Mary hospitals, call 844-925-0942.