Knee Arthritis and Total Knee Replacement

A: Almost certainly yes, at least with older-style metal detectors. Modern total knee replacements contain cobalt chrome and titanium alloy components, and these will typically trigger metal detector screening at airport security. This is a permanent feature of your new knee — it does not change over time.

Here is what to expect: you will likely be pulled aside for additional screening, which usually means a handheld wand or a pat-down around the knee. TSA agents are very familiar with joint replacements, and this is a routine, quick process. You do not need a special card or letter from your surgeon — TSA does not accept these as bypass documentation in the US.

For international travel, the protocols vary by country. Some countries and airports may ask for documentation from your surgeon confirming the implant. It is worth having a letter from our office on file if you travel internationally frequently — just ask us and we will provide one.

The good news: this is a minor inconvenience, not a limitation. Travel — including active travel like hiking trips and ski vacations — is absolutely something I expect my patients to get back to after knee replacement.

A: Robotic-assisted knee replacement has become one of the most talked-about topics in joint replacement, and for good reason — it represents a potential improvement and the future of surgery. Yes, I do offer robotic knee replacement, and I use the DePuy Velys Robotic Knee Replacement system for total knee procedures.

Unfortunately we are not to the point of robots actually doing surgery. Instead robotic-assist is just a way to use a computer to help plan the cuts of the knee to fit the implant. All decision-making and cutting are still done by the surgeon. For this reason, robotic-assist is not automatically “better.” In fact, the cuts I do using the standard technique with precise cutting jigs seem to be the same and usually I prefer the standard technique. I have not noticed any clinical difference between total knees done with robotic-assist and conventional technique.

One exciting technological development for the future is Augmented Reality Knee Replacement. I am a designer for the NEXTAR Partial Knee system for Medacta, Inc., which uses augmented reality technology for partial knee replacement. This is still in the works, but the future is exciting as technology, AI, patients, and surgery all collide and present new opportunities.

If you are curious whether robotic replacement is right for you, we will discuss it in clinic. Not every patient requires or benefits equally from robotic assistance, and I will give you an honest assessment.

A: Modern knee replacements are designed to last a very long time, and the data is encouraging. With current implants and techniques, approximately 90-95% of total knee replacements are still functioning well at 15 years, and many go significantly longer. The highly cross-linked polyethylene (plastic) spacer I use wears at approximately 1mm every 20 years — which gives you a sense of how durable the modern materials are.

The two main reasons a knee replacement may eventually need revision are: mechanical loosening of the implant from the bone over time, and wear of the plastic spacer. Both of these risks are reduced considerably by the cementless fixation technique I use in most patients, which allows your own bone to grow into the implant and create a permanent bond.

What can affect longevity on your end: body weight, activity level, and bone quality all play a role. Higher-impact activities over decades put more cumulative stress on the implant. This does not mean you cannot be active — quite the opposite, staying active and strong is good for your replacement. It does mean that truly high-impact activities like running and jumping are worth discussing in terms of long-term implant health.

The other big risk is infection. These can happen in the short term or long term, but fortunately are very rare. The rate of an infection happening around the time of surgery is about 1 in 200-300 patients because we have such an extensive infection prevention program. Later in life, especially if you become unhealthy or your immune system becomes compromised, an infection in your body can spread to your bloodstream and into your knee. Again, this is rare, but remains a risk for needing additional surgery.

The bottom line: most patients who receive a knee replacement today should expect it to last them the rest of their life, particularly if they are over 60 at the time of surgery. For younger patients, we have that honest conversation about revision rates upfront. It is part of planning the right surgery for the right person at the right time.

A: This is one of the most common things I hear in clinic — patients in their 40s and 50s who are suffering with severe arthritis but holding off because they think they are too young. My honest answer: there is no magic age for knee replacement. The decision is driven by the severity of your arthritis, how much it is affecting your life, and whether conservative options have been exhausted.

The concern with doing knee replacement in younger patients has historically been implant longevity — if your replacement lasts 20-25 years, a 50-year-old may need a revision surgery later in life. This is a real conversation worth having. However, modern implants with advanced materials and cementless fixation are performing better than ever, and the data on longevity continues to improve.

What I tell younger patients is this: if your knee pain is limiting your ability to work, be active, and enjoy your life, and if conservative treatments are no longer helping, waiting is not protecting you — it is just delaying your quality of life. I treat a lot of active, younger patients who want to get back to skiing, hiking, and pickleball, and their outcomes are excellent.
If anything, younger patients tend to go into surgery in better overall health and bounce back faster. Age is one factor in the conversation, but it is not the deciding one. Come see me and let us look at the full picture.

A: Recovering from total and partial knee replacement is a coordinated effort between the patient, the physical therapist and the surgeon. This starts long before surgery. I believe proper nutrition is important before surgery and this is covered in my video on protein needs in surgical patients. Studies have shown that increasing protein intake prior to surgery speeds muscle recovery after surgery.

As always, “stronger into surgery equals stronger out of surgery.” With diligent work on strength and maintaining range of motion of the knee before surgery, and with that effort continued after surgery, we are well on our way to an excellent outcome. As your surgeon, I will promise that I perform a technically excellent surgery and match your anatomy with the knee replacement so that you have full range of motion at the conclusion of the surgery.

A: Both operations only remove a minimal amount of bone and cartilage in the knee. The difference lies in the surfaces being replaced. Total knee replacement replaces all surfaces of the joint while partial replacement targets only the damaged section when arthritis is limited. This is described in better detail and with pictures in the video above.

A: This is a great question and one I think about carefully with each patient. Injections — whether cortisone, gel (hyaluronic acid), or more advanced biologics like PRP — can be very effective at managing arthritis pain. They are a legitimate part of conservative treatment, and I use them regularly. If they are working well, keep doing them!

The reality is that they work best in the earlier stages of arthritis, and for many patients, their effectiveness gradually decreases as the arthritis progresses.
Here is the biological reality: injections treat symptoms — pain and inflammation — but they do not slow or reverse the underlying cartilage loss. As the arthritis becomes more severe and the cartilage wears away, there is simply less cushion left for the injection to work with. The relief becomes shorter-lasting, then minimal, then nothing.

My honest advice: if injections are still giving you several months of meaningful relief and you are managing well, keep using them — they are buying you quality time. But when you find yourself coming back more and more frequently for injections that are lasting shorter and shorter, that is a signal that the arthritis has progressed to the point where surgery is likely the better long-term answer.

The goal of all of this — injections, physical therapy, medications, and ultimately surgery if needed — is the same: get you back to doing the things you love with as little pain as possible. I will always be honest with you about where you are in that progression.

A: I tell people that surgery is indicated when “the right patient has the right problem, at the right time.”

The right patient: Healthy enough to go through surgery, risk factors are minimized, and body weight is appropriate, etc

The right problem: The pain is coming from severe arthritis and other causes of pain have been excluded.  Ultimately knee replacement treats pain associated with cartilage and meniscus wear (arthritis).

The right time: Conservative treatment is no longer working and your pain is at a no longer tolerable level.  The right time also includes consideration of your work schedule, availability of people to help you, and you are mentally in a good place to dedicate time and effort toward recovery.

A: Yes! Arthritis is often missed with the wrong type of xrays. In clinic at an orthopedic office, we have specific arthritis xray views that require the patient to be standing. These are more complicated to get, but without the right xrays the knee can look normal when in fact there is significant arthritis. Come see us anytime if you need a full workup and if there is no arthritis, we will work together to figure out the problem.

A: These are common symptoms of arthritis, but other issues with the knee also present with the symptoms. The diagnosis is confirmed with specific standing xrays.