Knee Replacement Surgery in Hamburg, Germany: When Is It Necessary?

[00:00:00] When Is an Artificial Knee Joint Necessary?

[00:00:04] Hello and welcome to the Asklepios Health Podcast, the Asklepios health podcast with Kirsten Carla and doctors from Asklepios Clinics.

[00:00:17] Welcome to the Asklepios Health Program.

[00:00:21] Today we are talking about your knee. If you constantly have pain, if everyday life with your knee becomes increasingly difficult, then a knee prosthesis may be an option for you. And now we want to answer the question: Under what circumstances is this necessary? When should you decide to have one? How does the procedure work, and how long does recovery take?

[00:00:40] Joining me is Professor Dr. Frank Lampe, Chief Physician of the Department of Orthopedics and the Center for Endoprosthetics at Asklepios Klinik Barmbek. It is great to have you here, Professor Lampe.

[00:00:51] Yes, thank you very much. I am pleased to be here.

[00:00:55] Tell me, when am I ready for an artificial knee joint? Is there a specific point in time?

[00:01:01] For me, the decisive factor is always the level of suffering — your personal level of suffering. Usually, there is a history of knee problems. Various treatment options have already been tried, especially non-operative, conservative treatments. Then there comes a point when you say, "None of this is helping me enough anymore." My quality of life is poor, I have a very high level of suffering, and perhaps I can no longer manage my daily activities. I can no longer pursue my hobbies. That is when you have to start considering whether surgery might be able to help.

[00:01:36] So, I think "level of suffering" is the key phrase. Is there an age range for this? Do you say, "You are too young for this"?

[00:01:43] Not really. There are also relatively young patients who already suffer from severe osteoarthritis. Perhaps they had an accident when they were young that led to it. For them, too, the rule is: if the level of suffering is significant, if their quality of life is no longer satisfactory, and they have exhausted non-operative treatment options, then the time has come to consider a knee prosthesis. And regarding older age, there is actually no upper age limit. Of course, you always have to consider how healthy the patient is and whether they have any risk factors. But an older person who is gradually becoming immobile and losing mobility can also benefit from a knee prosthesis. Losing mobility is a significant event, and they can naturally benefit just as much from a knee replacement.

[00:02:31] Do you always have to implant a total knee prosthesis right away?

[00:02:35] No, you don't. There are actually patients whose osteoarthritis is limited to a specific area of the knee joint. The entire knee is not affected. In such cases, it is possible to implant what is known as a partial prosthesis, often called a unicompartmental knee prosthesis. It is not suitable for every patient. Each case has to be examined very carefully. But for a certain group of patients with partial osteoarthritis of the knee, this partial or unicompartmental prosthesis can be a very good solution.

[00:03:09] So, you have to be able to point to the exact spot and say, "This is where it hurts"?

[00:03:14] That would actually be the ideal situation. The patient points to a specific area and says, "This is exactly where I have my pain." If I then see on the X-ray that there is cartilage loss in that same area, and the osteoarthritis is localized there, then that is a good indication for a partial or unicompartmental prosthesis.

[00:03:30] So what is the advantage of that? As a patient, I would probably say the less I have implanted in my body, the better. Is that really the case?

[00:03:41] Basically, that is correct. A large part of the knee joint is preserved, including the areas that are not worn. That is certainly an advantage. Only the actually damaged area is replaced by the artificial joint. As a result, the procedure is somewhat smaller compared with a total replacement. We have found that patients often achieve somewhat better function in the end than with a total knee prosthesis. They also often have a stronger feeling that "this is my knee joint" — a more natural sensation, which is often better preserved with a partial prosthesis than with a total prosthesis.

[00:04:15] If you say the patient needs to point to one specific area, does that also mean the rest of the knee has to be intact?

[00:04:21] Exactly. The ligaments have to be intact. We need intact collateral ligaments, as well as an intact anterior and posterior cruciate ligament. They should be intact because these partial joints depend on intact ligament guidance. They need this to function properly.

[00:04:40] If you were to recommend a total knee prosthesis, what would the process be? We know what is going on in the knee and I decide that I want treatment. You treat me and I want a total prosthesis.

[00:04:54] We always begin with a detailed medical history. We discuss the patient's problems in order to properly assess them. Then a clinical examination is performed. We assess how mobile the knee still is, how stable the ligaments are, where the pain is, and how severe the pain is. After the knee examination, we perform diagnostic imaging, usually an X-ray. In cases of advanced osteoarthritis, a standard conventional X-ray is often sufficient. You do not necessarily need an MRI. We then look at the X-ray to determine how advanced the osteoarthritis is, how far the cartilage loss has progressed, and where it is most pronounced. Based on these findings, we can decide whether a prosthesis is the right solution for the patient.

[00:05:46] Like the one on the table?

[00:05:47] Exactly. This is an example of a model. I can show it to you. You call it a total prosthesis, but they are actually called surface replacement prostheses. And there is a reason for that. Many patients imagine that when an endoprosthesis is implanted, the entire joint is removed. But that is not the case at all. The joint is essentially preserved, including its ligaments. Only the damaged surfaces are removed. I can demonstrate this. Essentially, if you like, using the example of the thigh bone, it is basically like placing a crown over the joint with this prosthetic component. This means that only very thin slices of bone are removed and then replaced by the implant. The actual joint remains preserved, including the ligaments that guide and stabilize the joint. In the end, the artificial joint functions and moves much like a natural joint.

[00:06:45] How do you know that it is positioned correctly? You are removing some of the knee, after all. The patient is lying there in front of you, not standing or walking. But afterward, the knee has to function properly during movement.

[00:07:02] In addition to the clinical examination, we also perform a special X-ray to plan the knee before surgery. A digital measurement image of the knee is created. Then, before the operation, we can use the X-ray and computer to plan the position of the implant. During the operation, we then have appropriate aids, such as cutting guides and measuring templates, that help us position the knee joint so that it functions as optimally as possible afterward. One goal is always to straighten the leg axis. For example, if a patient comes into surgery with severe bow legs, the knee joint has to be implanted so that after surgery the leg is properly aligned. This is very important. There are various tools available for conventional surgery. There are also modern computer-assisted procedures that allow us to make the entire process even more precise.

[00:08:01] So they are probably particularly useful for difficult cases?

[00:08:02] They are particularly suitable for difficult cases where it is challenging to find the optimal positioning, align the leg precisely, and stabilize the ligaments perfectly. We always want to restore the most natural possible kinematics of the artificial joint. These computer-assisted procedures allow us to work even more precisely than with conventional methods.

[00:08:29] Can you explain in more detail how the measuring and computer system works?

[00:08:32] There are navigation systems. These are computer-assisted systems that allow us to measure the kinematics and anatomy of the knee joint. This can be done using imaging before surgery or during the operation, creating an individual digital, virtual model of the patient's knee on the computer. During the operation, we can use this computer model to plan the ideal position of the knee joint. Navigation then helps us in difficult cases. Modern robotic systems can also help implant the prosthesis exactly as planned.

[00:09:20] Can the computer make suggestions that you, as a human, might reject?

[00:09:26] Exactly. That is an important question. The computer does not work autonomously. It only provides the surgeon with highly precise measurement data, based on which the surgeon decides how the prosthesis should be positioned. I often compare it to a navigation system in a car. It suggests certain routes, but it is your decision as the driver whether to follow the route or take a different one. It does not actively take control of the steering wheel. You drive the car, while the navigation system provides precise data so that you always know where you are and what a possible route to the destination is. It is exactly the same with computer systems in the operating room.

[00:10:07] And what is the advantage for the patient?

[00:10:10] The quality of the result — the functionality of the knee joint and how long the knee lasts — are naturally related to how perfectly the implant is positioned. For example, I mentioned the straight alignment of the leg axis, or the perfect balancing of the ligaments. These systems simply help the surgeon achieve this more precisely than with conventional surgical instruments. You can implant it with millimeter- and degree-level precision. This is generally not possible with manual instruments to the same degree. Therefore, we can hope for improved treatment outcomes.

[00:10:56] Does this also mean that patients can get back on their feet faster?

[00:11:00] Yes, that is certainly possible. But I believe it is primarily aimed at improving long-term results. That is where the effect is likely to be more noticeable. In terms of quickly regaining joint function and achieving rapid rehabilitation, I think other factors are even more important. For example, how we handle the soft tissue and whether we operate as gently as possible. There is a term that many people know: minimally invasive surgery. It works particularly well for the hip. With the knee joint, you have to think about it somewhat differently. Nevertheless, we naturally try to preserve the soft tissues as much as possible. I believe these are factors that help patients get back on their feet faster. The precision of the implant may also have an effect, but the main goal is better long-term results, better function, and greater durability. The prosthesis should last longer. Those are the main goals.

[00:11:58] And when will my knee be ready for normal use? I know the saying, "The knee takes a long time."

[00:12:01] That is not entirely wrong. You have to distinguish between different things. For everyday functionality — getting back to normal daily life — this takes place during the rehabilitation phase after surgery. I would say that approximately four to six weeks is the period in which patients can generally regain everyday functionality. Everyday functionality also includes the ability to work, but that naturally depends heavily on the occupation. This always has to be discussed and decided individually with the patient. With modern rehabilitation methods, patients are already mobilized for the first time on the day of surgery. They still need walking aids, of course, but they are already helped out of bed and can take their first steps. During the first few days, they learn to move around the hospital ward and also climb stairs. After that, the actual rehabilitation phase begins, which usually lasts around three weeks. Patients can then return home and generally manage their everyday activities quite well. People often say not to drive for six weeks. That is a general rule of thumb. But to be honest, I always tell patients that if they are planning something such as a round-the-world trip or redesigning their garden, I would definitely allow three months of recovery time. And I think your question also touches on the fact that the knee joint continues to develop afterward. It is quite possible that even after six or nine months, further improvement can occur. For example, mobility may continue to improve. But the major improvements generally occur during the first few weeks after surgery.

[00:13:45] Thank you very much for this interesting conversation.

[00:13:47] Thank you.

[00:13:48] And we will see you again on www.asklepios.com, on Facebook and YouTube, or in the next podcast. Stay healthy.