Stylianos Toumasis is a renowned specialist in orthopedics and trauma surgery who specializes in hip, knee, and shoulder joint replacement. As a senior physician and director of the Joint Replacement Center (EPZmax) at Nardini Klinikum Landstuhl in the Kaiserslautern district, he brings extensive expertise and many years of experience to his role. His additional qualifications in specialized orthopedic surgery, sports medicine, physical therapy, as well as manual medicine and chiropractic therapy enable him to take a holistic approach to the orthopedic care of his patients.
A distinctive feature of his work is the use of minimally invasive methods in hip arthroplasty, such as the AMIS technique. This gentle procedure allows for the implantation of hip prostheses with less tissue damage and a faster recovery time. Dr. Toumasis also has extensive experience performing hip revision surgeries, which are necessary when an existing prosthesis needs to be replaced. In the field of knee arthroplasty, Stylianos Toumasis relies on state-of-the-art, robot-assisted surgical techniques.
The Nardini Clinic is renowned for its excellent care in joint replacement and has established itself as a center for comprehensive care. To ensure the high quality of the procedures, Stylianos Toumasis and his team have undergone specialized training, and the surgical staff has also received comprehensive training in the use of robotic technologies. Since 2013, the clinic has been certified by EndoCert as a maximum-care provider, which means that strict quality standards are adhered to in order to ensure optimal patient care.
Through close collaboration with experts from various specialties, including anesthesiology, radiology, physical therapy, and vascular surgery, Stylianos Toumasis provides comprehensive and interdisciplinary care for his patients. This holistic approach ensures that patients receive the best possible support not only during surgery but also during follow-up care and rehabilitation. Patients under his care benefit from comprehensive care that ranges from the initial diagnosis to full rehabilitation, with the goal of sustainably improving their mobility and quality of life.
The editorial team of the Leading Medicine Guide had the opportunity to learn more about robot-assisted knee replacement and minimally invasive hip replacement using the AMIS method during an interview.
Modern joint replacement surgery has made significant advances in recent years, offering patients new hope for improved treatment outcomes. In particular, robot-assisted knee replacement and minimally invasive hip replacement using the AMIS method are at the forefront of these innovations. While robotic technology enables unparalleled precision and personalized treatment, the AMIS method relies on minimally invasive procedures to accelerate recovery and improve quality of life.
The introduction of robot-assisted techniques for knee replacement has significantly improved the precision and outcomes of these surgeries.
“Before we delve into knee joint endoprosthetics, we should first establish a basic understanding of the pathology of the knee joint. The knee (along with the hip) is one of the largest joints in the human body and bears the heaviest load. In addition, people are living longer (in fact, we’re gaining about two years of life expectancy every ten years), which means that by 2060, approximately 32% of the population in Germany will be over 65 years old. This trend alone is expected to lead to an increase in joint wear and tear. Osteoarthritis is the most common cause of knee problems that lead patients to require a knee replacement. In about 90% of cases, the cause is osteoarthritis. In the remaining 10%, the causes include severe obesity, rheumatism, or previous injuries. As a general rule, all conservative treatment options are exhausted before considering knee replacement surgery. These include medication, dietary changes, physical therapy, the use of orthotics, and similar measures. However, if the patient finds that, despite these approaches, they can no longer cope and their quality of life is severely impaired, the question of a knee replacement arises. Further diagnostic tests are then conducted at the clinic to assess whether a knee replacement is indicated. In the past, it was mainly people over the age of 60 who found themselves in this medical situation. Today, however, we are also seeing an increasing number of osteoarthritis cases among people aged 40 to 60. One reason for this is that many younger people have engaged in more intensive sports in the past. In the 1980s and 1990s, for example, tennis and soccer were particularly popular. This often led to micro-injuries—for example, to the cruciate ligament or meniscus—which have a negative impact on the knee over the years. As a result, younger patients are now also coming to us seeking help,” explains Stylianos Toumasis at the beginning of our conversation.
Robot-assisted surgery has proven particularly valuable for certain patient groups undergoing knee replacement, as it enables unparalleled precision and customization.
By using robot-assisted systems, the surgeon can make more precise adjustments to achieve optimal leg alignment and joint function—something that is more difficult to achieve with traditional methods. Mr. Toumasis, a specialist in knee arthroplasty, comments: “Surgeons have always strived to implant prostheses correctly, because only then will a prosthesis last a long time and the patient experience less pain. For over 25 years, we have been using technology to improve knee replacement surgery. Initially, it was navigation, and for several years now, we have been in the next stage of technological development: robotics. This means that during surgery, we surgeons use a computer to assist us—one that, of course, does not dictate what we should do, but rather supports us in planning and during individual steps, confirming them to ensure the prosthesis is implanted with complete precision. Because the procedure is less traumatic for the patient, they experience less pain and can leave the hospital much sooner. A robotic surgery takes no longer than a standard procedure—typically 60 to 90 minutes. Robot-assisted surgery is particularly helpful in very difficult cases, such as when a patient has bowlegs or knock-knees. We perform nearly all surgeries with the help of the robot—about 250 patients per year—since there are no exclusion criteria for the use of this technique.”
The precise placement of the prosthesis not only ensures better functionality but can also extend the implant’s lifespan, as the exact alignment distributes the load more evenly and reduces wear and tear. This is particularly important for patients who engage in regular physical activity or work in physically demanding professions. Another area where robot-assisted surgery is particularly beneficial involves patients who have already undergone multiple knee surgeries and now require knee replacement surgery. In such complex procedures, it is crucial to position the prosthesis with the utmost precision in order to overcome the existing challenges and specific complications resulting from previous surgeries. Robotic technology offers detailed and precise planning, which is essential for the success of these revision surgeries.
The AMIS method, which stands for “Anterior Minimally Invasive Surgery,” is an advanced approach to hip replacement surgery characterized by its minimally invasive technique.
“The AMIS method is the only minimally invasive, intramuscular technique used in hip replacement surgery that involves operating from the front. It is a highly innovative technique that has been established for about 20 years and which we have been using as the standard method at our clinic in Landstuhl for over 15 years. It has clearly proven its worth, as patients benefit enormously: they experience less pain because we are able to preserve muscle tissue. As a result, they are discharged from the hospital sooner and return to their daily lives more quickly. Only small scars remain, and there is a significantly reduced risk of the prosthesis dislocating or of developing a limp,” explains Mr. Toumasis.
The small anterior approach allows surgeons to insert the hip prosthesis without cutting through or significantly damaging the large muscles surrounding the hip joint. Instead, the tissue is gently pushed aside.
“Of course, you need experience in hip replacement surgery, good surgical skills, and the appropriate technical equipment to perform surgery using the AMIS method. For example, an extension table is necessary for the precise positioning of the operated leg and optimal positioning of the patient to ensure the best view. In addition, specialized surgical instruments and specific implants are required. Our surgeons attend training courses for this method, which we use at the clinic about 550 times a year. “We perform more than 95% of hip replacements using the AMIS method. Only in the case of overweight patients can the anterior approach be technically more challenging,” reports Mr. Toumasis.
Preoperative planning and imaging are crucial elements for the success of both robot-assisted knee replacement and the AMIS method for hip replacements. In both procedures, a detailed preoperative analysis enables a customized and precise execution of the surgeries, which significantly improves outcomes for patients.
One of the main challenges with the AMIS method is adapting to the minimally invasive approach. The surgeon must adjust to working under these confined conditions, which requires extensive training and experience. The surgical techniques and instruments differ significantly from established methods, which demands additional practice and experience. Surgeons must not only familiarize themselves with the specific technique but also learn how to effectively utilize the reduced field of view and the limited range of motion in the access area.
“For all patients, we conduct careful preoperative planning using specialized software that allows us to plan the prosthesis in detail even before the surgery. For example, we determine the size of the acetabulum and the size of the stem with an accuracy of 2 millimeters. The entire plan is displayed on our monitor, allowing us to ensure that the implantation proceeds exactly as planned. In addition, we take X-rays during the operation, which serve as an important tool for double-checking every step. As a full-service provider, we are obligated to have all necessary resources on-site to manage even complex cases intraoperatively. This allows us to respond flexibly to unforeseen requirements, such as inserting additional screws or using cement. “In select cases, the AMIS method can also be used for revisions—for example, when only part of the prosthesis needs to be replaced,” explains Mr. Toumasis. He adds regarding the requirements for the surgical technique:
“At first, the AMIS method is certainly a challenge. It’s important that the surgical team is well-coordinated. By now, we only need 45 to 60 minutes for such an operation. When a prosthesis is implanted using the AMIS method, patients are generally very satisfied. The prostheses also appear to last longer, although this has not yet been conclusively proven. Nevertheless, one can assume a lifespan of at least 20 to 25 years. The method originated in France, is frequently used in Switzerland, and is increasingly being used in Germany as well, albeit in only about 20 percent of cases. In addition to knee and hip replacement surgery, we offer the full spectrum of orthopedic services at our orthopedic clinic in Landstuhl, such as conservative and surgical treatment of spinal disorders, sports injuries, arthroscopic surgery, foot surgery, and osteology.”.
Thank you very much, Mr. Toumasis, for the helpful explanation!
