State-of-the-art technology in orthopedics

Interview with Paweł Łęgosz, MD, PhD, from the Department of Orthopedics and Locomotor Traumatology, MUW.

Endoprosthetic procedures, or hip and knee replacements, are among the most commonly performed major procedures in orthopedics. How many of these are performed annually at your Department?

Paweł Łęgosz, MD, PhD: About a thousand, which is definitely more than 5-6 years ago.

What is the reason for this trend?

P.Ł.: In recent years, there have been significant advances in orthopedics. Both in implant technology, physician training and rehabilitation after surgery. As a result, the eligibility criteria for endoprosthetic surgery have changed. In the past, qualification was delayed for a long time. Usually until there were typical clinical features indicating that the patient needed to be operated on. Today, we do not wait until the last minute. When there is pain that prevents daily functioning and there is significant joint dysfunction - we immediately refer for surgery. Incidentally, hip replacement has been ranked by the WHO as one of the three most important surgeries in the world. Also in the top three were bypass and kidney transplant. What these procedures have in common is that they have proven to be breakthroughs in medicine and allow a person to return to the fitness they had before the condition occurred.

What else could have contributed to the increase of treatments?

P. Ł.: Let us not forget that our population is aging, so there is a natural increase in patients who require endoprosthesis. At the same time, seniors want to be active and are seeking information about endoprostheses themselves. After the surgery they return to activity and are an example to their peers that the procedure is effective. The lifting of limits on knee and hip replacement by the National Health Fund has also contributed to the increase in the number of procedures. It was in 2017, and since then we've been able to do a lot more of those surgeries. We operated not only in the morning, but also in the afternoons and on Saturdays. In this way, we have been able to significantly reduce the queues of patients waiting for surgery. The years 2018-2019 were a golden streak for Orthopedics when it comes to endoprosthetic procedures.

And what is the situation today?

P. Ł.: I think that today the waiting time for a procedure is a year to a year and a half. At least in our department. We try to systematically unload the queue. However, the pandemic is making it much more difficult for us. Currently, we are able to perform 3-4 surgeries per day. We can't operate more because due to the pandemic, the anesthesia team is working on covid wards. Nevertheless, I am hopeful that we will soon be able to return to pre-pandemic status.

 
Who needs endoprosthetic surgery most often?

P. Ł.: We mostly treat elderly people with advanced degenerative changes in their joints. But not only. We also have middle-aged patients who, for example, suffered from Perthes disease in childhood or have congenital hip dysplasia. We also get a lot of patients with sterile necrosis of the femoral head. They are referred from three transplant clinics operating within our hospital. Sterile necrosis of the femoral head is a complication after immunosuppressive treatment used after transplantation. Among the patients are also  very young people. The youngest was 18 years old when we first put her in an endoprosthesis. Then, when she turned 21, she needed a second one. The girl had leukemia as a child and was on immunosuppressive treatment. We also operated on a 19-year-old boy. As a child, he underwent a hemipelvicectomy, which is a resection procedure of the entire hip plate with the hip joint due to osteosarcoma. After successful oncological treatment the boy wanted to return to full activity. And this was possible due to a special custom-made 3D printed implant.

What does a standard endoprosthesis procedure consist of?

P. Ł.: Endoprosthesis procedure is the replacement of damaged joints with artificial ones. Such procedures were performed as early as the 1970s. Of course at that time the implants were not as perfect as they are today. Some of their components were made of polyethylene and were quite easily damaged.  Today we have implants made with new technology. They are coated with various substances that can bond to the bone tissue. They also have reduced friction surfaces to a minimum. We can assume that such an implant will last 15-20 years. In general, endoprosthesis is now the gold standard in the treatment of osteoarthritis and gives the best prognosis.

You have mentioned custom-made implants. How do they differ from standard ones?

P. Ł.: Custom-made implant is prepared individually for the patient, you can say that it is "tailor made" with the use of 3D printing. Modern technology allows us to accurately recreate the geometry of the joint and, as a result, fit the implant perfectly. This is the key issue. You may come across information on the internet that the success of endoprosthesis surgery depends on from which access it is made. This is not true. Recent reports from American orthopedic journals make it clear that the ideal implant placement is responsible for the success of the surgery. And it is the custom-made implant that brings us closer to having the prosthesis seated in an absolutely perfect way. There's a big boom in the world right now for these implants. They are not readily available for financial reasons. However, more and more centers are opting for them.

You performed the first operation with a custom-made implant in your department in 2014. Was it a pioneering procedure in Poland?

P. Ł.: We pioneered the use of custom-made implants in non-oncologic cases. Today, we use them especially in revision or repair surgeries when there is significant destruction of the acetabulum or the femur. According to the guidelines presented nowadays at the world congresses, surgery with a custom-made implant should be performed when two revision surgeries have failed. In our department, we have so far performed 30 procedures with custom-made implants. Both in oncology and non-oncology patients. So far none of them have needed a repair procedure so far. And that's what we're all about, that the patient doesn't come back to us after joint replacement surgery. Motivated and encouraged by the good results, we began to think about using custom-made implants in situations of primary osteoarthritis of the hip and knee. We performed the first non-commercial custom-made primary knee replacement surgery in Poland.

Custom-made and mixed reality implant surgery took place in 2019. You and your team received the "Golden Scalpel" for this procedure. How did you use the mixed reality technique?

P. Ł.: I really like technical innovations, I am interested in them and I am always looking for benefits in them for the surgeon and for the patients. While preparing for my custom-made implant surgery, I thought I could use mixed reality glasses as well. I combined the two technologies into one. In the glasses I had all the information gathered about the patient, i.e.: the lesion in a 3D version, the shape of the damaged acetabulum and the design of the implant. This made my work much easier. The operation turned out to be pioneering both in Poland and in the world. Then I further refined some details related to the use of mixed reality glasses. I used them again, performing a custom-made implant placement procedure on a patient who had metastatic renal cell carcinoma of the proximal femur. It was a highly vascularized metastasis. The level of femoral resection and replacement of the resected bone with an endoprosthesis had to be precisely matched. In the glasses, I had a complete plan of the procedure and the exact location where it was best to resect (cut) the bone. Let me add that the tumor was not only in the bone tissue, but also in the soft tissues. Therefore extreme precision was needed.

What are the benefits of using new technologies?

P. Ł.: The biggest benefit is the increased safety of the procedure. With the mixed reality glasses, I can prepare for surgery very carefully. I walk into the operating room and know exactly what awaits me, no surprises. During the surgery I am able to precisely map the surgical field and overlay all the information I have uploaded to my glasses. I can make an appropriate resection, I know where the so-called red flags are, that is, pathological vascularization and where the normal vascularization is. So I can economically and very precisely perform the procedure. It is also 20-30 percent shorter than comparable surgery without the use of mixed reality technology. For the patient, this means they have a minimized risk of complications and a faster return to normal function. I am very happy that we can use technological novelties in our department. Americans are interested in the project of combining custom-made technology and mixed reality. This time it is they who follow the trail we have marked out, not the other way around.

So where is orthopedics heading today?

P. Ł.: The future is personalized medicine as well as collaboration between doctors and engineers. When it comes to orthopedics, it's not just about 3 D printing and custom-made implants, but the entire surgical plan. If I send the patient's records, including a CT scan of their joints, an engineer from a custom-made implant company is able to put together a customized plan for the surgery. He can tell me the exact size of the acetabulum that needs to be used, all the angles the implant needs to be placed at, and he can show me how to recreate the center of rotation and what the right size of the stem is. This ensures that the implant is placed as accurately as possible and eliminates the risk of complications. Another very important direction in orthopedics is the introduction of robotics. Of course, the robot will not replace the surgeon, but will be his assistant. Such an assistant has the entire imaging diagnosis of the patient in its memory and helps in the selection of the implant and its perfect positioning. It protects us surgeons from making the slightest mistake when inserting an endoprosthesis. Today in Poland, robotic procedures are not popular because such a device costs 3-4 million PLN. At the same time, the robotic procedure is not reimbursed by the National Health Service. But I hope that this will change with time.

Interviewed by: Iwona Kołakowska, MUW