Robot-Assisted Knee Replacement and Personalized Medicine in Knee Replacement: An Expert Interview with Prof. Hirschmann

Professor Dr. Michael Hirschmann is an internationally recognized expert in orthopedics and traumatology with special expertise in knee surgery and knee arthroplasty. As president of the Personalized Arthroplasty Society and a board member of leading professional societies such as the German Knee Society and the European Society of Sports Traumatology, Knee Surgery, and Arthroscopy, he shapes both research and clinical practice in his field. With over 450 scientific publications and numerous international awards, he has established himself as one of the leading experts on knee injuries and knee osteoarthritis.

Prof. Dr. Hirschmann has made a significant contribution to the development of personalized medicine in knee surgery and is setting innovative standards in knee arthroplasty. In particular, with his concept of phenotyping and phenotype-based positioning of knee prostheses, as well as the use of modern technologies such as 3D-printed prostheses and robot-assisted surgery, he has ushered in a new era in individualized patient care. His approach enables a more precise adaptation of prostheses to patients’ specific needs and contributes significantly to improving postoperative outcomes.

In addition to his clinical work, Prof. Dr. Hirschmann is deeply committed to the advancement of orthopedics and knee surgery. As director of the University Center for the Musculoskeletal System at the Baselland Cantonal Hospital, he fosters close integration between research and clinical practice and ensures that state-of-the-art orthopedic treatments are combined with holistic musculoskeletal rehabilitation. The combination of academic expertise and innovative technologies makes him a driving force for orthopedic care in the region and beyond.

The editorial team of the Leading Medicine Guide spoke with Professor Dr. Hirschmann and learned about exciting developments in robot-assisted knee replacement and personalized medicine in knee replacement surgery.

Robot-assisted knee replacement and personalized medicine are revolutionizing knee surgery and offering patients more precise and individualized treatment. The use of state-of-the-art robotic technology optimizes the positioning of knee prostheses, which can lead to better outcomes and a faster recovery. In combination with personalized medical approaches tailored to each patient’s specific phenotype, this innovative technology enables customized care that significantly improves patients’ quality of life. These advances offer new hope for patients with knee osteoarthritis and set new standards in orthopedic surgery.

Knee osteoarthritis and other degenerative knee conditions that require a knee replacement are usually caused by a combination of mechanical stress, biological degradation processes, and individual risk factors. 

“Knee osteoarthritis can generally be divided into two main types: primary and secondary osteoarthritis. Secondary osteoarthritis usually results from previous injuries or surgeries on the knee. It can also be caused by rheumatic diseases that damage the tissue in the joint and ultimately lead to osteoarthritis. In primary osteoarthritis, the cause is less clear-cut and is often described as mechanical wear and tear of the articular cartilage, which is usually caused by a misalignment of the knee. Such a misalignment can occur, for example, with a leg alignment abnormality such as bowlegs, which places greater stress on the inner part of the joint, causing it to wear down more rapidly. With bowlegs, on the other hand, it is the outer part of the joint that experiences more pressure. In many cases, these two main causes lead to osteoarthritis. Knee osteoarthritis is a very common condition, especially among people over the age of 60. “According to estimates, 70 to 80 percent of people in this age group already have knee osteoarthritis to a greater or lesser degree,” explains Prof. Dr. Hirschmann at the beginning of our conversation, adding:

“The first symptoms of knee osteoarthritis often prompt those affected to see a doctor quickly, especially if they suddenly notice more severe swelling in their knee joints or pain on the inner or outer side of the joint. Often, only a few months pass between the onset of symptoms and the first visit to the doctor, although the symptoms typically follow a fluctuating course—at first they are more severe, then they improve, only to worsen again later. But even if the symptoms initially subside, they continue to worsen over time. Eventually, patients seek treatment. At this stage, there are still many options for alleviating the symptoms without surgery. In addition to physical therapy, which is an important part of treatment, injection therapies are also used. Common options include hyaluronic acid, cortisone, and autologous blood therapy. In some cases, adipose tissue is also used; it is processed and reinjected into the affected joint to support healing or provide relief.”

Personalized medicine in knee replacement offers decisive advantages over standardized treatment methods, as it is tailored to the anatomical conditions, biomechanical requirements, and specific needs of each patient. 

“In traditional medicine, the focus is often on developing therapies and diagnoses suitable for a broad segment of the population. This approach is based on the principle that one solution works for many people at the same time. In contrast, personalized medicine takes a different approach: It places the specific needs of the individual patient at the center. Particularly in orthopedics, and especially in knee replacement surgery, this represents a significant paradigm shift. In the past, standardized solutions were developed based on the average needs of patients. These standardized prostheses were often only roughly adapted to the individual circumstances of the patients. Today, however, a new approach is being taken. Instead of applying one-size-fits-all solutions, the patient’s individual knee joint is analyzed and treated with great precision. Prostheses are no longer manufactured according to a general standard size; instead, their positioning and design are increasingly tailored to the patient’s specific anatomy. This individualized approach enables much more precise and effective treatment. A particularly important component of this advancement is the use of modern 3D printing technologies. With the help of 3D printing, both the prostheses and the necessary instruments can be manufactured with the highest precision and customized to the patient’s anatomical needs. “These technologies offer the possibility of creating customized solutions that provide patients with a significantly better fit and functionality of the prostheses,” Prof. Dr. Hirschmann explains.

A key advantage lies in the precise selection of the knee prosthesis, which can be exactly adapted to the patient’s natural joint shape and alignment using modern imaging techniques such as high-resolution MRI or CT scans. This not only achieves a better fit but also ensures the most natural possible kinematics of the knee joint. Another advantage lies in the optimized positioning of the prosthesis. With the help of computer-aided planning procedures and robot-assisted surgery, surgeons can perform the implantation with the highest precision. This reduces the risk of malalignment, minimizes wear on the prosthesis components, and ensures even load distribution within the joint. This, in turn, can extend the prosthesis’s lifespan and reduce the need for revision surgery. While standardized knee prostheses are often manufactured and implanted based on general average values, personalized medicine can help replicate natural movement as closely as possible and sustainably improve the quality of life for those affected.

Robot-assisted knee replacement represents a significant advance in orthopedics, as it enables exceptionally precise and individually tailored implantation of knee prostheses. 

Compared to conventional procedures, in which the surgeon works manually using anatomical reference points, robot-assisted surgery utilizes state-of-the-art imaging technologies, computer-aided planning, and mechanized precision instruments to ensure the exact placement and alignment of the prosthesis. 

“With robotic assistance, surgeons can measure the knee joint more accurately during surgery to ensure the best possible alignment and positioning of the prosthesis. Another important tool is the measurement of ligament tension curves, which are recorded individually for each patient during surgery. This technique makes it possible to restore a more stable knee joint. Robot-assisted knee surgery is not about a robot performing the entire procedure on its own. Rather, it involves a navigation system that helps the surgeon precisely position the prosthesis and measure ligament tension. The surgeon remains the one who performs the entire operation, while the robot serves merely as a precise aid. “This technology has the advantage of increasing the precision and accuracy of the operation,” says Prof. Dr. Hirschmann, adding:

“Patients are generally well-informed about this technology, and many specifically opt for robot-assisted surgery because they are convinced that this method delivers more precise results. In practice, however, no technology is completely error-free, and it is emphasized that the surgeon must have solid experience in knee replacement surgery before using robotic technology. Only then can the surgeon correctly interpret and apply the robot-assisted data. “Fundamental experience in knee arthroplasty is therefore a prerequisite for fully leveraging the benefits of robot-assisted systems.”

Another advantage of robot-assisted technology is the preservation of surrounding tissue. Since the robot removes only the absolutely necessary bone material and soft tissues such as muscles, tendons, and ligaments are preserved as much as possible, this results in less tissue trauma. Compared to conventional methods, patients often experience less postoperative pain, and mobility can be restored more quickly. In addition, robot-assisted surgery enables dynamic intraoperative adjustment. During the operation, the system can analyze the patient’s individual ligament tension at various degrees of flexion and, if necessary, adjust the positioning of the prosthesis. This is particularly important for ensuring natural joint movement and minimizing the risk of instability or restricted movement.

Robot-assisted surgery is playing an increasingly important role in reducing recovery time and improving knee joint function after surgery. 

“The duration of the recovery period following robot-assisted knee surgery varies by patient, but in general, patients experience faster rehabilitation and improved knee joint function. The length of the hospital stay has decreased in recent years due to advances in surgery; however, the actual length of stay also depends heavily on financial and organizational factors. A key factor in the durability of prostheses is precise positioning, which can be further optimized through the use of robotic technology, thereby potentially extending the prosthesis’s lifespan,” emphasizes Prof. Dr. Hirschmann.

“In my own professional practice, I have worked extensively with these advanced, robot-assisted systems over many years and have gained valuable experience that is of great importance to my work. This years-long experience is crucial, as the true benefits of the technology can only be fully realized when the surgeon is thoroughly familiar with the systems and able to use them in a targeted and precise manner. One particularly important aspect I would like to highlight here is the close connection between personalized medicine and robot-assisted surgery. This synergistic combination is a key factor in significantly improving treatment outcomes. It is important to understand that robotic technology alone does not guarantee success. Rather, it is the precise and targeted application of these innovative technologies, combined with the surgeon’s in-depth experience, that creates enormous added value for patients. Only when both factors—advanced technology and the surgeon’s in-depth knowledge—are applied in harmonious synergy can modern surgical techniques in knee replacement surgery achieve their full potential. This leads to safer procedures and significantly better outcomes that sustainably improve patients’ quality of life. “In this context, surgery becomes not only more efficient, but also significantly more precise and reliable,” Prof. Dr. Hirschmann emphasizes at the end of our conversation.

Thank you very much for these interesting insights, Professor Dr. Hirschmann!