Stem cell therapy is a promising approach in modern medicine aimed at repairing or replacing damaged or diseased tissues through the targeted use of stem cells. Stem cells are characterized by their ability to differentiate into various cell types and to self-renew, making them a unique tool for the treatment of numerous diseases.
The editorial team of Leading Medicine Guide learned about how stem cell therapy is used in modern medicine—and specifically in joint regeneration—during a conversation with the highly sought-after specialist Professor Dr. Aristoteles Kaisidis.
Stem cells are particularly well suited for the repair or replacement of damaged tissue because they possess unique properties that no other cell type has to the same extent. On the one hand, they are able to renew themselves over long periods of time and continuously produce an unlimited number of new stem cells.
This ability of self-regeneration ensures that a long-term reservoir for tissue renewal is available, which is particularly important in chronic diseases or severe injuries. On the other hand, stem cells have the ability to differentiate, meaning they can develop into various specialized cell types such as cartilage cells, muscle cells, or nerve cells. This allows them to be used in a targeted way to replace exactly the type of tissue that has been lost due to disease or injury.
Another key advantage is their adaptability to different environments and signals within the body. Stem cells respond to chemical, physical, and biological stimuli from their surroundings, allowing them to integrate into existing tissue and support its healing processes.
This property makes them especially valuable for tissue types that naturally regenerate only to a very limited extent, such as heart muscle, nerve tissue, or joint cartilage. In practice, this means that stem cells can not only replace damaged cells but can also actively promote the body’s own repair mechanisms.
The treatment of joint diseases with stem cells differs fundamentally from conventional therapeutic approaches because it follows a regenerative strategy, whereas traditional methods primarily act symptomatically.
Conventional therapies—such as pain medications, anti-inflammatory drugs, cortisone injections, or physiotherapy—primarily aim to relieve discomfort, reduce inflammation, and maintain joint mobility.
They address the symptoms of the disease, such as pain and stiffness, but do not treat the underlying damage to joint cartilage or other tissue structures. In contrast, stem cell therapy addresses the root cause of the damage directly.
Stem cells, which can be obtained for example from the patient’s own blood, bone marrow, or fatty tissue, have the ability to differentiate into cartilage cells or other relevant tissue types.
„The stem cells are obtained through what is known as liposuction. In this process, fat is taken from the superficial tissue directly beneath the skin, usually from the abdomen. This is done using syringes without incisions and only under local anesthesia. The extracted fat is then processed in special devices, which takes approximately 30 to 40 minutes.
During this process, the stem cells are filtered out of the fat—around two to two and a half million of them. These stem cells are then injected into the affected joint; in our practice this is often the shoulder, but also the knee or hip. The method can also be used for muscle diseases—or more generally, it can be applied to soft tissue as well.
Essentially, it is a form of cell transplantation. The entire procedure takes about one and a half hours, and afterward the patient can go home. The procedure carries very little risk“, explains Prof. Dr. Kaisidis, while also pointing out that there are patients for whom the procedure cannot or should not be used:
„There are indeed a few cases in which this procedure cannot be applied. One example involved an extreme athlete who had virtually no fat in the abdominal area—truly none at all. This is extremely rare even among elite athletes. In his case, fat had to be taken from the gluteal region instead, which is generally possible, although the superficial fat directly under the abdominal skin is usually preferred.
This area contains around 200-times more stem cells than bone marrow, for example. Stem cells from bone marrow are more commonly collected for severe diseases such as leukemia, meaning blood cancer. However, for the procedure described here there are clear exclusion criteria: it should not be performed in severely ill, multimorbid patients, nor in individuals with known cancer diagnoses.
Patients who take two different blood-thinning medications are also not suitable, as hematomas could easily occur in the abdominal area. These are the most important situations in which the treatment should be avoided“.
The treatment follows the same principle for all joints—whether shoulder, knee, hip, or ankle.
„The injected stem cells reach the affected joint directly. These are so-called primitive cells—cells from which all other cell types in the body can develop. They use exactly this potential: they can transform into the types of cells that are missing in the damaged tissue. Within the joint, the stem cells recognize where a defect exists—for example cartilage damage in osteoarthritis, where the original cartilage cells have already worn down or disappeared completely.
Through specific receptors, the stem cells attach to the affected area of the bone and begin to transform into cartilage cells. With a probability of around 72 to 75 percent, a new single-layer cartilage structure forms. This procedure therefore offers the possibility of treating osteoarthritis without joint replacement and renewing the worn tissue in a natural way“, Prof. Dr. Kaisidis describes the course of treatment.
Patients usually notice an improvement relatively quickly—at least the first effects. However, the actual remodeling process in the joint takes time and is largely completed after about one to three months.
Prof. Dr. Kaisidis comments: „The newly formed cartilage cells do not last ‘forever’ but are subject to normal wear and tear like all other cells in the body. How pronounced this wear is depends greatly on lifestyle: someone with an office job or moderate physical strain will wear down cartilage far less than a craftsman, tile layer, or someone who participates in intensive sports.
The degree of wear is therefore highly individual, but fundamentally normal. Older patients can also benefit from the treatment. For example, someone in their early 70s with shoulder problems and limited mobility may often become stable enough after therapy that, if otherwise in good condition, they can even return to playing tennis.
In principle, the therapy is suitable for people of all ages: elite athletes, competitive athletes, recreational athletes, manual laborers, or patients with cartilage damage following accidents. In professional sports in particular, a major advantage is that this is not a medication and therefore does not constitute doping. In addition, recovery time is often significantly shortened, which is extremely valuable for athletes and sports clubs“.
To perform such stem cell therapy, the treating physician does not need additional formal specialist training in the classical sense, but must possess official state authorization.
„The required authorization to perform stem cell therapy is granted by the responsible state authority—for example a state government or a public health department. Without this formal application and the corresponding approval, the therapy may not be performed. Both ethical and professional considerations lie behind this requirement.
The intention is to prevent someone from seeing the method once and then assuming they can simply perform it. There are clear spatial, hygienic, and organizational requirements that must be fulfilled. Only when these conditions are demonstrably met and the physician possesses the necessary knowledge is authorization granted.
If the conditions are not fulfilled, the therapy is not permitted. The therapy itself has existed for several years. In the United States in particular, it has now become almost standard, and in many other European countries it has been used for considerably longer and more frequently. In Germany it has been available for approximately eight to ten years.
Numerous studies worldwide document the effectiveness and scientific foundations of the method. It is therefore not an experimental procedure but a well-studied form of therapy for which many publications can be found in scientific journals“.
Many patients are actually unaware that this form of stem cell therapy even exists. Out of one hundred affected individuals, perhaps one or two know about this option—if any at all.
„In practice, no patient has reported that they had previously heard about it. The number of clinics in Germany offering this procedure is also extremely small—you could literally count them on one hand. Of these few centers, only two—Bonn and our clinic here in Frankfurt—actually have high case numbers.
The others perform the therapy only occasionally, if at all. True specialized centers are therefore rare. Nevertheless, there is no large influx of patients simply because the method is not widely known—even in professional sports, where one might assume interest would be particularly high. Here at the Red Cross Clinics in Frankfurt, approximately 750 to 850 such treatments are performed each year.
Patients usually travel here from all over Germany“, emphasizes Prof. Dr. Kaisidis, concluding our conversation.
Many thanks, Professor Dr. Kaisidis, for this fascinating insight into stem cell therapy!
- Specialist in Orthopedics and Trauma Surgery
- Chief of Shoulder Surgery, Red Cross Clinics Frankfurt
- Specialist and pioneer in modern shoulder surgery
- Focus areas: shoulder arthroplasty, arthroscopy, shoulder stabilization, rotator cuff tears, sports and trauma injuries
- Expert in tendon transfers (latissimus dorsi and pectoralis major transfer) and complex revision surgery
- Developer and patent holder of the Kaisidis Plate (anatomical mini plate for tendon ruptures and fractures)
- Use of state-of-the-art minimally invasive surgical techniques, including arthroscopic prosthesis implantation
- Innovator in regenerative medicine: SVF autologous fat stem cell therapy for osteoarthritis and shoulder diseases
- Director of a highly specialized shoulder clinic equipped with the latest medical technology
- Approximately 700 shoulder surgeries and 5,000 outpatient shoulder patients annually
- Highly sought-after expert for complex cases and medical second opinions
