Dr. Marcus Mumme is a leading figure in orthopedics, specializing in the treatment of knee problems in patients of all ages. He has been working as a knee specialist and sports orthopedist at the Sportclinic Zurich since October 1, 2024, and is a leading expert in his field. Dr. Mumme focuses on the treatment of sports injuries, cartilage damage, and complex knee problems, as well as growth-related issues. His expertise ranges from conservative therapies and joint-preserving surgeries to modern cartilage cell transplants and biomaterial-based bone marrow stimulation. In addition to his outstanding professional expertise, he is known for his empathy and sensitivity in dealing with his patients.
Dr. Mumme plays a crucial role in this highly qualified team, which addresses a wide range of orthopedic challenges in children and adolescents. In particular, he has specialized in knee surgery to help patients with sports injuries or congenital abnormalities. From rotational corrections to the treatment of patellar tracking, he offers a wide range of solutions. His therapeutic options also include innovative procedures such as arthroscopic surgeries and regenerative therapies.
Through his membership in scientific societies—since 2022, he has chaired the Cartilage and Meniscus Committee of the Society for Arthroscopy and Joint Surgery (AGA)—he contributes significantly to the advancement of his field. Dr. Mumme is actively involved in international research projects on the treatment of cartilage defects and osteoarthritis at the University of Basel and the Sportclinic Zurich. He is known for his pioneering work in the field of regenerative medicine and has made significant contributions to the development and refinement of techniques for cartilage regeneration.
The editorial team of the Leading Medicine Guide spoke with Dr. Mumme about innovative approaches to cartilage therapy for sports injuries.
Sports injuries can cause significant damage to cartilage, which can lead to long-term problems such as osteoarthritis. Cartilage therapies for sports injuries aim to restore or regenerate the damaged cartilage in order to preserve joint function and relieve pain. These treatments are often used in combination with physical therapy to achieve optimal rehabilitation and restoration of joint function. Early diagnosis and treatment are crucial to preventing long-term complications and getting athletes back on the field.
Traumatic knee injuries, such as those that can occur during sports accidents, include dislocations and fractures, which can directly damage the cartilage. Meniscal tears and ligament tears are also among these injuries, which can lead to cartilage degeneration.
Overuse injuries occur due to repetitive stress or improper movements. In particular, sports that place heavy stress on the joints—such as running, jumping, or tennis—can lead to microtrauma in the cartilage. Over time, this microtrauma can develop into cartilage damage. In addition, certain chronic conditions such as rheumatoid arthritis and gout can lead to cartilage damage. These conditions are often accompanied by joint inflammation, which can attack the cartilage. If left untreated, these conditions can lead to progressive cartilage degeneration.
“When participating in sports—whether skiing or playing soccer—knee injuries can, of course, occur from time to time, and they can vary widely. There is also a normal risk of injury during other recreational activities and in everyday life. The patient typically then sees a doctor, who first asks about the circumstances of the injury, the symptoms, and also examines the knee. This is followed by further diagnostic tests, which always include an X-ray and an MRI to rule out or confirm specific injuries,” explains Dr. Mumme at the beginning of our conversation.
In some cases, an arthroscopic examination may also be necessary. In this procedure, a small camera is inserted into the joint to directly inspect the cartilage. This minimally invasive technique allows the doctor to accurately assess the extent of cartilage damage and perform repairs immediately. Early diagnosis and appropriate treatment of cartilage damage are crucial for preventing long-term complications such as osteoarthritis and preserving joint function. This may involve a combination of conservative measures, such as physical therapy and anti-inflammatory medications, as well as surgical interventions in some cases.
Cartilage plays an extremely important role in joint mobility and stability, particularly in the context of athletic activities.
“Cartilage is fundamentally important for joint function and primarily acts as a shock absorber where two bones move against each other, such as the thighbone and shinbone. Here, the cartilage lubricates the movement through synovial fluid. And when the cartilage is no longer present—as is the case with osteoarthritis, for example—this can result in bone rubbing against bone, leading to inflammation, swelling, and pain. “If this is not treated, the symptoms persist and worsen, leading to progressive wear and tear,” explains Dr. Mumme. Good cartilage health not only supports performance during athletic activities but also helps prevent injuries and avoid long-term damage to the joints. Therefore, it is important to support the cartilage through a balanced diet, appropriate exercise, and avoiding excessive strain. Caring for the cartilage is crucial for keeping the joints healthy and functional and for preventing sports injuries.
For cartilage damage caused by sports injuries, various non-surgical treatment options are available, which can be used depending on the severity of the injury and the patient’s individual needs.
“There are, of course, ways to treat cartilage damage conservatively. These primarily include physical therapy to strengthen the muscles and achieve stabilization. Various fascial techniques can also help relieve pain. This is because the pain does not originate exclusively from the joint itself, but also from the muscles. It’s also important to keep an eye on any underlying conditions. This includes maintaining a healthy body weight, ensuring adequate vitamin D levels, following a healthy diet, and getting enough exercise. However, you should not overexert yourself and should generally avoid sports that carry a high risk of injury, as the risk of injury is too great. Even if you do strength training, you shouldn’t overdo it with the weights. “You have to find a good middle ground,” recommends Dr. Mumme.
Anti-inflammatory medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) can relieve pain and inflammation associated with cartilage damage. Injections of hyaluronic acid or corticosteroids into the affected joint can also help relieve pain. Special dietary supplements containing glucosamine and chondroitin sulfate can also help support cartilage health and promote the regeneration of damaged tissue.
Early diagnosis and treatment of cartilage damage can help prevent or at least slow down long-term consequences such as osteoarthritis.
Dr. Mumme also points out a few aspects to consider when engaging in sports: “Fundamentally, it’s often a matter of getting good advice—even when it comes to sports activities. Ultimately, it’s always up to the patient to decide how much risk they’re willing to take, especially when it comes to their personal quality of life—for example, in extreme sports. In addition to the recommendation not to overexert oneself, attention should be paid to recovery periods and overall physical fitness; depending on the sport, this also includes appropriate footwear, good equipment, and adequate playing conditions for certain ball sports to prevent potential injuries.”
There are various types of cartilage therapies that can be used to treat cartilage damage.
“On the one hand, there are simple therapies in which small holes are made in a cartilage defect during arthroscopy (microfracturing), to stimulate cartilage formation, all the way to more complex therapies where a tissue sample is taken from the knee to isolate the cells and culture them in the lab, which are then later reimplanted into the defect. One must ask which procedure is suitable for which situation. After all, there are also small cartilage defects that do not require extensive treatment, as even a less invasive approach can yield very good results. Other types of cartilage damage, however, require more extensive treatment. These therapies range from minimally invasive procedures to open joint surgery,” explains Dr. Mumme regarding the basic options. Injection therapies can also be used to relieve pain and inflammation. In addition, there are special dietary supplements that can help support cartilage health and promote the regeneration of damaged tissue.
The use of cartilage from the nasal septum—also known as a nasal cartilage graft—represents a promising advance in cartilage therapy, particularly in the treatment of cartilage damage in older patients or in challenging revision cases.
This approach offers an innovative solution aimed at repairing or replacing damaged cartilage in the knee joint by harvesting healthy cartilage tissue from the patient’s nasal septum and transplanting it into the affected joint. The cartilage in the nasal septum is structurally similar to the cartilage tissue that lines the joints. This makes it an ideal candidate for transplantation into the knee joint, as the transplanted tissue interacts well with the surrounding joint environment and integrates into the existing cartilage tissue.
“In particular, stem cells from the bone marrow—and to some extent, joint cartilage cells as well—have a limited ability to form healthy cartilage, a capacity that diminishes as the patient ages. Laboratory studies have shown that the cartilage in the nose is of the same anatomical type as that found in the knee joint—so-called ‘hyaline cartilage.’ Even in older individuals—that is, those aged 40 and older—the cartilage in the nasal septum still retains an outstanding ability to form cartilage. This is the basis for the idea that it can be put to good use. “We developed the technique in the lab and were able to demonstrate in Phase 1 and Phase 2 studies that it is a safe procedure and is also suitable when conventional therapies reach their limits,” explains Dr. Mumme, before going into further detail:
“We have cartilage in various parts of our body. For example, our outer ear also derives its stable shape from cartilage. However, this is a different type of cartilage, known as ‘elastic cartilage.’ We also have cartilage in our ribs and trachea, where it serves to provide structural support. Similarly, the cartilage in the nasal septum helps stabilize the airway. And since it is of the same anatomical type, it can perform the same function in the knee joint. As for the direct cartilage harvest from the nose, you can think of it as similar to a visit to the dentist. Under local anesthesia, a small sample can be taken—a procedure that takes about 30 minutes—from which many cartilage cells can be cultured to create a cartilage cell graft. The cells are processed in the laboratory for one month. The patient then returns after one month, and the cartilage is implanted in the knee during surgery. You can think of the cartilage as a small flap, about 4 to 5 cm in size, that is inserted at the site of the defect in the knee. The patient then stays in the hospital for 3–5 days and, after six weeks, undergoes a fairly intensive rehabilitation program with physical therapy, using walking aids. The main age group is between 18 and 60 years old. The procedure is officially approved as part of an ongoing study for patients up to age 65, because specific criteria have been established and, in cases of doubt, additional medical conditions may be a factor. “We wanted to keep the complexity to a minimum here,” he adds,
“What’s unique now is that we’re also using this cartilage procedure for an osteoarthritic indication—specifically, osteoarthritis behind the kneecap. This is a major step forward, because standard cartilage therapies weren’t very effective in this area. I personally performed the first nasal cartilage transplant in 2012, and I first treated osteoarthritis behind the kneecap with nasal cartilage in 2022, continuing to do so with very positive results. A new study has now shown that so-called stem cell injections have not yet fully met expectations. These injections appear to have more of a placebo effect and are no more effective than a saline solution or a cortisone injection. The results of high-quality studies in this area have been somewhat disappointing. “With the nasal cartilage technique, however, we have already successfully treated over 100 patients!” And with this positive statement, we conclude our conversation.
Thank you very much, Dr. Mumme, for this very insightful conversation!
