Dr. Stylianos Toumasis is Head of Endoprosthetics and Director of the Endoprosthetics Center of Maximum Care (EPZmax) at the Nardini Klinikum St. Johannis in Landstuhl near Kaiserslautern. As a specialist in orthopedics and trauma surgery with several additional qualifications – including Special Orthopedic Surgery, Sports Medicine, Physical Therapy, as well as Manual Medicine and Chiropractic Therapy – he brings exceptionally broad and well-founded expertise. He combines his medical competence with management know-how: a Master of Science in Health Care Management complements his profile and enables him to combine medical excellence with efficient care structures.
Stylianos Toumasis specializes in hip, knee, and shoulder endoprosthetics. In hip replacement surgery, he particularly focuses on minimally invasive techniques such as the AMIS method, which allows prostheses to be implanted with muscle-sparing techniques and shorter rehabilitation times. He also has extensive experience in revision surgeries for both hips and knees. In the field of knee endoprosthetics, he uses the most modern robot-assisted procedures, especially the CORI system (Computer Assisted Orthopedic Robotic Instrument), which enables precise, individually tailored implant positioning – a key factor for the durability and functionality of artificial joints.
The Nardini Klinikum in Landstuhl, where Dr. Toumasis practices, performs more than 800 endoprosthetic implantations annually, making it one of the leading institutions in the region. As a certified EPZmax, it meets the highest quality standards, which are regularly reviewed as part of the EndoCert certification process. Here, an interdisciplinary team of specialists, nurses, physical therapists, and orthopedic technicians works closely together to provide patients with comprehensive care from the first consultation through follow-up. A particular focus is the treatment of advanced osteoarthritis of the hip and knee. When conservative measures are no longer effective, state-of-the-art surgical techniques are used. For example, the AMIS method for hip osteoarthritis allows faster mobilization after surgery, while robot-assisted knee surgery with partial or total prostheses is tailored individually to the patients’ anatomy.
Stylianos Toumasis stands for highly precise, patient-centered, and compassionate medical care. His goal: to relieve pain, preserve mobility, and sustainably improve quality of life – using the latest technology, medical expertise, and a team committed to the well-being of every single patient.
The editorial team of the Leading Medicine Guide took the opportunity to once again talk to Dr. Stylianos Toumasis about the successful AMIS method in hip endoprosthetics.
.jpg "Stylianos Toumasis_Specialist for AMIS")
The implantation of a hip prosthesis is one of the most common and successful orthopedic procedures when quality of life is severely restricted by osteoarthritis or other degenerative diseases of the hip joint. In recent years, surgical techniques have continuously evolved – with the goal of providing patients with faster recovery, less pain, and the most natural mobility possible. Particularly noteworthy is the AMIS method (Anterior Minimally Invasive Surgery), a minimally invasive approach through the anterior hip musculature. This technique spares muscles and soft tissue, which generally results in less blood loss, shorter rehabilitation, and earlier mobilization. The AMIS method has now become an established procedure in modern hip replacement surgery and represents a particularly gentle and effective treatment option for many patients.
The AMIS method fundamentally differs from conventional surgical techniques for hip prosthesis implantation, especially in terms of the chosen access route and handling of soft tissue.
While traditional approaches, such as the lateral (side) or dorsal (rear) access, often require cutting or detaching muscles and tendons, the AMIS method uses an anterior approach through a natural muscle gap. „The AMIS method, in which hip prosthesis implantation is performed from the front – that is, anteriorly – represents an innovative and significantly less invasive technique compared to classic approaches. Whereas conventional methods often cut or detach muscles and tendons, the AMIS method uses a specific access route that optimizes muscle and nerve protection. What makes this method unique is that no tendons are cut and no muscles detached, which significantly reduces soft tissue damage. The anterior access, though anatomically complex, allows optimal visualization of the surgical field through the use of special instruments and precise joint exposure. Despite its higher degree of difficulty due to limited visibility, this technique is not only safe but also very precise. Experienced surgeons need about 40 to 50 minutes for a prosthesis implantation via the AMIS approach – comparable to conventional techniques. The decisive advantage for patients is the significantly lower muscle and tendon injury, which results in less blood loss, a reduced need for blood transfusions, and a lower likelihood of postoperative complications such as dislocation. Studies show that the revision rate with this method is considerably lower, thanks to the precise placement of the prosthesis and minimal soft tissue damage“, explains Dr. Stylianos Toumasis at the beginning of our conversation and continues:
„Thanks to the optimal selection of instruments and the special positioning of the leg on an extension table, excellent visibility of the joint is achieved, allowing for more precise implantation. The incision for the AMIS method is usually only 6–8 centimeters long, approximately the length of a conventional scar. Thus, this minimally invasive technique is not only gentle but also extremely precise, which significantly improves the longevity and stability of the prosthesis and reduces the probability of revision surgery. The surgical access in the AMIS technique runs between the sartorius muscle and the tensor fasciae latae muscle. As a result, no muscle is cut or detached from the bone, leading to significant preservation of muscular and tendinous structures. This approach minimizes intraoperative trauma and typically allows faster mobilization of patients. In addition, postoperative pain is usually less, which accelerates the rehabilitation process and reduces the need for pain medication. The risk of certain complications, such as prosthesis dislocation or long-term muscle weakness, is also lower with this approach. However, the AMIS method requires precise technical execution and corresponding surgical experience, as the access is more demanding due to the limited anatomical space. It offers a modern, gentle alternative in hip replacement surgery, which – with appropriate patient selection and in experienced hands – provides clear advantages for recovery and postoperative quality of life“.
When using the AMIS method for hip implantation, the surgical environment changes significantly. The patient is positioned on a special, highly precise operating table, where the operated leg is stabilized securely. The patient’s upper body remains untouched by the surgical team, while the anesthesiologist administers anesthesia. The positioning allows the procedure to be performed under either general or regional anesthesia, offering important flexibility for patients with certain pre-existing conditions.
„During surgery, only one assistant works with the surgeon on the operative side. This is a major advantage compared to other methods, which usually require two assistants. The instrumentation is handled by a specially trained nurse, who provides the required tools to the surgeon, thereby ensuring efficiency and precision. As for technical equipment, the specialized devices for the AMIS method, especially the extension table, represent an investment that many hospitals now possess, though it still remains high-performance equipment not available everywhere. While the AMIS technique was rarely used in southwestern German hospitals in the past, it has now spread significantly. The clinic that consistently applies this method is one of the leading institutions, performing the most AMIS prosthesis implantations, including revision surgeries. In revision surgeries, such as socket or head replacements, the minimally invasive AMIS method offers benefits through less blood loss, no muscle damage, and faster resumption of weight-bearing. However, AMIS is not suitable for every revision procedure“, says Dr. Toumasis, adding:
„Navigation technologies generally play a smaller role in hip implantation using the AMIS method compared to knee replacements, since the technique relies on precise manual planning. Although robotic systems are used in other areas of orthopedics, their use in hip replacement with the AMIS method is rather the exception, as the procedures can usually be performed relatively quickly and without significant advantages from robotic assistance. Surgical planning in the AMIS method is mostly based on modern imaging and individualized anatomical planning. Limitations exist only in cases where the surgical area is compromised by infection, prior surgeries, or vascular involvement. With growing experience, the method has also been successfully applied in overweight patients, which has significantly expanded its flexibility and applicability“. .jpg "Photo Minimally Invasive Access with AMIS")
Postoperative pain management and mobilization time differ significantly in patients treated with the AMIS method compared to those undergoing other minimally invasive or conventional surgical techniques.
Studies and clinical experience show that many patients can be mobilized just a few hours after surgery, as pain is lower and muscular function largely preserved. This contrasts with posterior or transgluteal approaches, where muscle groups often have to be detached or cut, leading to stronger postoperative pain, muscle insufficiency, and delayed mobilization. .jpg "Photo No muscles or tendons are cut with the anterior AMIS approach")
„Follow-up care usually takes place in the outpatient practice of the patient’s orthopedic specialist. After about six weeks, recovery progress is checked by the patient’s orthopedist. For special situations or complications, patients can return to us at any time. The experience of being cared for from surgery through recovery follow-up is seen as a major advantage for our patients. In addition, we send out a questionnaire about one year after surgery to gather honest feedback on satisfaction and any potential issues. These responses are important data for us to further improve quality“, emphasizes Stylianos Toumasis. 
The Nardini Klinikum St. Johannis is a recognized and certified Endoprosthetics Center of Maximum Care. Certification is based on the highest quality standards, reviewed by independent auditors. This makes it one of the leading clinics in Germany offering comprehensive care for joint replacement surgery. The center stands out for its close interdisciplinary collaboration, modern technical equipment, and a highly qualified team of specialists. .jpg "Photo Dr. Toumasis with hip prosthesis")
„In our clinic, interdisciplinary collaboration is a key component of treatment concepts. After surgery, discharge usually occurs after about five to seven days, depending on the individual rehabilitation schedule. Rehabilitation appointments are organized at the time of surgery scheduling, so rehab can begin seamlessly after the operation. Our clinic is accredited as a certified Endoprosthetics Center of Maximum Care, successfully re-certified continuously since 2013. Certification is based on high standards verified by external auditors. Close cooperation with anesthesiologists, internists, physiotherapists, and social workers is essential. We follow standardized procedures that are nevertheless tailored individually to each patient to ensure optimal care. The goal is to minimize complications and optimally support recovery“, explains Dr. Toumasis, and adds:
„Although patient satisfaction does not play a direct role in certification, we view it as an important parameter to continuously optimize care. We respond specifically to both positive and negative feedback to constantly improve treatment. Certification is based on objective quality indicators such as surgery time, complication rate, and the number of blood transfusions. For quality assurance and monitoring, all data are recorded in national registries, such as the Endoprosthesis Register, which documents all prosthesis-related complications. The high quality of our AMIS method is reflected, for example, in significantly lower complication and blood transfusion rates compared to conventional techniques“. 
The AMIS method represents a comparatively complex surgical technique that requires a certain learning period for the surgeon.
Dr. Toumasis explains: „Despite its relative simplicity compared to some other procedures, the AMIS method has a shallow learning curve, meaning it is quite teachable but requires consistent practice and mentoring by experienced colleagues. It is important that surgeons apply the standards and specifics of this method regularly, as practical experience gained through frequent surgeries makes the decisive difference. There are special courses where physicians can learn the technique, but the key is that it must be internalized through continuous practice and guidance by seasoned surgeons, not through occasional experience. How quickly someone masters the technique depends greatly on individual talent: some need only a few weeks to operate safely, while others may take up to a year to fully develop routine. In our clinic, training and further education take place within daily practice. We perform more than 500 hip replacements annually, many of them with the AMIS method. For over 15 years, we have carried out more than 5,000 minimally invasive hip surgeries this way. The surgeons who master this method are senior lead surgeons and lead surgeons of the center, who can document at least 50 or 100 prostheses per year, respectively. This ensures that every operation is performed by an experienced specialist who safely masters the technique and guarantees optimal treatment results“.
The current evidence with long-term data over more than 15–20 years is promising and supports the assumption that the AMIS method can contribute to improved prosthesis stability and thus to a lower revision rate.
It is in any case advisable for patients to turn to a certified Endoprosthetics Center of Maximum Care, where surgeons can demonstrate consistently high case numbers. Such centers also maintain a comprehensive portfolio of implants to respond flexibly to various situations.
„Currently, the AMIS method is considered a forward-looking option that is also being applied in selected revision surgeries. Due to the precise placement of the prosthesis, minimal tissue damage, and shorter hospital stays, this technique is not only gentle on patients but also economically sensible. It is expected that in the coming years, this method will become increasingly standardized and could even be performed on an outpatient basis, further optimizing treatment processes. Preoperative planning is increasingly done with modern imaging to tailor implantation precisely to individual anatomy. With current developments, it is therefore important for patients to choose experienced and qualified clinics in order to achieve the best possible outcomes. The ongoing advancement of the technique, the greater focus on outpatient procedures, and quality assurance through certifications and registries help make treatment safer, more efficient, and more patient-oriented“, concludes Stylianos Toumasis, and with that, we end our conversation.
Thank you very much, Dr. Toumasis, for your insights into modern hip surgery using the AMIS method!
