Priv.-Doz. Dr. Marcus Mumme is a board-certified specialist in orthopedics and traumatology and is among the leading experts in the field of knee and sports surgery in Switzerland. At the Sportclinic Zurich Hirslanden, where he has been practicing since October 2024, he focuses on comprehensive orthopedic care for patients with knee joint disorders – in both amateur and elite sports.
His particular interest lies in regenerative therapies for osteoarthritis and cartilage damage, where he sets clinical and scientific benchmarks. PD Dr. Mumme has extensive experience in both conservative and surgical treatment of the knee joint, especially in cases of ligament injuries, meniscus damage, and complex joint malalignments. His clinical work is complemented by a strong commitment to research: as the former Head of Cartilage and Regenerative Knee Surgery at the University Hospital Basel and of Sports Orthopedics at the University Children’s Hospital Basel, he played a key role in developing innovative techniques, including the transplantation of cartilage cells from the nasal septum – a procedure with high future potential.
The SportClinic Zurich Hirslanden combines state-of-the-art orthopedic medicine with a strong focus on personalized care. Formerly a high-performance sports clinic, it has evolved into a leading center for orthopedic surgery, treating patients of all ages. In this setting, Dr. Mumme contributes his expertise to develop tailored solutions together with an interdisciplinary team – always with the goal of preserving or restoring mobility and sustainably alleviating discomfort. His work is defined by high professional standards, many years of clinical experience, and a deep understanding of the needs of athletes and individuals with chronic joint problems.
The editorial team of Leading Medicine Guide spoke with PD Dr. Mumme and received up-to-date insights into cartilage therapy options and regenerative treatment approaches for osteoarthritis.
Cartilage therapies play a central role in modern orthopedics, particularly in the treatment of joint damage and osteoarthritis. While conservative measures often provide only limited relief, regenerative methods open up new perspectives to preserve or restore joint function. In clinical practice and innovative studies, a wide range of approaches are currently being explored and applied, aiming to repair cartilage defects and slow the progression of osteoarthritis. These developments hold the promise of sustainably improving patients’ quality of life.
In clinical practice, various regenerative procedures have proven particularly effective in treating cartilage damage and osteoarthritis.
“There are several regenerative procedures that have become established for cartilage damage and osteoarthritis. The choice of therapy largely depends on the extent and type of damage – for example, whether only the cartilage is affected or also the bone and other tissues of the knee joint. Treatment ranges from simple conservative methods, such as physical therapy, to complex procedures in which the patient’s own cells are harvested and cultured in the lab to regenerate the damaged tissue. A new and promising approach is nasal cartilage-based therapy, which is already being applied in studies for osteoarthritis behind the kneecap. However, there are already proven procedures for other types of cartilage defects. It is important to note that causes and risk factors must be taken into account; no method is applied in isolation but usually in combination with treatment of the underlying risk factors”, explains PD Dr. Mumme.
Innovative studies play a central role in advancing and optimizing cartilage therapies by systematically testing new treatments and refining existing ones. Clinical studies allow for objective assessment of the effectiveness, safety, and long-term outcomes of new therapies, forming the basis for evidence-based recommendations. Both novel regenerative techniques and combination therapies are being investigated, aiming to promote cartilage regeneration and modulate joint inflammation.
Regarding the studies, PD Dr. Mumme explains: “In order to bring a regenerative therapy like nasal cartilage treatment into actual use for patients, several steps are required, usually taking many years. At present, there is already a temporary approval allowing treatment of a limited number of selected patients. Meanwhile, extensive clinical studies are underway to evaluate the efficacy and safety of the therapy. These studies are typically randomized and controlled, meaning patients are assigned to different treatment groups to objectively compare which therapies yield the best results. Patients are monitored regularly throughout the study, and the effort involved is not significantly greater than that of follow-up care for standard therapies, including imaging procedures and clinical examinations. The aim is to strengthen the evidence base to enable broader approval”.
These studies generally take many years, including follow-up phases to monitor long-term effects.
“During this period, patients can already receive the therapy in a controlled setting, and the results help refine the treatment. The collected data are then analyzed, condensed, and submitted through scientific publications and regulatory approval applications. The next critical step is applying for market approval, after which the treatment could become broadly available. Cost coverage is also a major factor. For insurance companies to reimburse the therapy, the data must be highly convincing and the benefits clearly demonstrated. Industry support is equally important to ensure production, quality assurance, and broad availability. The example of nasal cartilage therapy highlights how complex and lengthy the development process is. It requires collaboration among an interdisciplinary team of scientists, physicians, clinical specialists, regulatory authorities, and industry partners to bring innovative treatments from research to standard clinical application”, notes PD Dr. Mumme.
The implementation of regenerative cartilage therapies in daily clinical practice presents various challenges. Many of these procedures are technically demanding and require specialized expertise as well as close interdisciplinary collaboration, for example between orthopedic surgeons, radiologists, and physical therapists. Careful patient selection is crucial, as not every cartilage injury or stage of osteoarthritis can benefit equally from regenerative therapy. Particularly advanced osteoarthritis with severe joint degeneration often sets limits to regenerative approaches.
“Once treatment begins, the follow-up process typically extends over about two years. In the initial phase, close monitoring occurs, for example two and six weeks after therapy, to track healing. Later, follow-ups are spaced further apart: semi-annually, at one year, and finally at two years. During this time, data are collected to evaluate treatment efficacy and analyzed within the study. Regarding efficacy in knee osteoarthritis, patients often notice first improvements after about six months. These gains usually increase in the following years, especially after one to two years. Studies suggest that results are generally stable after five years, though long-term data beyond ten years are still lacking, leaving durability uncertain. Success also varies individually and depends on factors such as overall muscle condition, weight, and lifestyle. Patients who are well-trained, of normal weight, and free of risk factors such as smoking usually benefit more. For study purposes, severely obese patients (over BMI 35) are not included, as they carry higher risks of complications and poorer risk-benefit ratios. For significantly higher obesity, weight reduction is strongly recommended prior to treatment. Patients with rheumatologic conditions such as rheumatoid arthritis or infectious knee arthritis are also excluded, since these underlying diseases generally rule out regenerative therapies. In general, the age limit for current studies is 65 years; younger patients show significantly better prospects. Active, athletic individuals, including elite athletes, are also part of these studies, using treatment primarily to preserve mobility and sports capability in young, active adults and professional athletes”, says PD Dr. Mumme. 
For participation in the study focusing on patellofemoral osteoarthritis, the required number of patients is carefully planned to ensure meaningful results.
“For one of the ongoing studies, for example, we determined a sample size of 75 patients. These are evenly randomized into two treatment groups to compare different procedures. The exact number of participants always depends on the study design and assumptions made during planning. In patient care, it is important to us to provide honest and transparent information. Participation is strictly voluntary, and patients are fully informed about treatment options, procedures, and effort involved. They must know that they can withdraw from the study at any time. For the study focusing on patellofemoral osteoarthritis, the situation is that there are few standard alternatives besides prosthetics. This increases patients’ willingness to participate. Dr. Mumme offers this specialized therapy at the Sportclinic Zurich both within the study framework and under limited approval. Patients from more distant regions can in principle participate but must consider that regular follow-ups are required. With very long travel distances, there is a risk that patients may miss follow-ups, which would significantly compromise the study evaluation. Without continuous monitoring, the validity of the study results could be seriously limited, as treatment progress must be documented. Beyond medical treatment, a healthy lifestyle is very important for success. This includes balanced nutrition, weight management, regular exercise, avoiding overstrain while maintaining consistent muscle strengthening. Proper sports equipment, good cushioning and stabilizing shoes, and optionally knee braces are also valuable. These factors help improve knee resilience and secure long-term treatment success”, explains PD Dr. Mumme, adding:
“Overall, it can be observed that injuries, sports injuries, and overuse damage are on the rise, mainly due to increasing physical activity in the population. These trends lead to a higher incidence of related conditions. In addition, obesity rates are rising, representing another risk factor for joint issues. Society as a whole is aging, making age-related knee wear more common. These demographic factors also contribute to a likely increase in disease rates. An even more decisive factor, however, is the simultaneous rise in physical inactivity, especially among young people. Less exercise and activity result in weaker muscles and a higher risk of injury or premature wear. Taken together, all these factors suggest that the burden on the knee joint will likely increase in the future”. 
A significant innovation in regenerative cartilage therapy is the intraoperative use of PRP (platelet-rich plasma), i.e., autologous blood, which is injected directly into the affected joint during surgery – already applied at the Sportclinic Zurich.
On this, PD Dr. Mumme comments: “This method aims to support the body’s own healing processes and improve the repair of cartilage defects. Although the use of PRP in this context has not yet been widely established as a standard, there is growing evidence that it can enhance the outcomes of cartilage regeneration. At the Sportclinic Zurich, intraoperative PRP application has already been integrated into routine clinical practice. During surgery, when cartilage reconstruction is performed, PRP is injected into the joint to stimulate new cartilage tissue formation. This approach extends traditional procedures and aims to increase healing chances, as the growth factors in PRP promote regeneration. However, performing this technique involves greater organizational and medical effort, as production and application of PRP during surgery must be precisely planned. This requires specially trained staff and the necessary equipment on-site. Currently, this treatment is not yet available in all clinics, as it has not become a standard procedure”.
The ongoing study investigating the effectiveness of nasal cartilage therapy is expected to continue for several more years.
“The exact duration is difficult to predict, but the current plan is to continue data collection and analysis for at least three to five years. The aim is to create a broader evidence base through this international collaboration involving several centers in Germany, Italy, Croatia, Sweden, and Austria, to validate the method for broader clinical application. Long-term outcomes and safety of nasal cartilage use in cartilage therapy should eventually also set future standards for treatment concepts. The results of these studies and clinical experiences will therefore not only improve treatment in Zurich but also in numerous other centers worldwide”, says PD Dr. Mumme, concluding our conversation.
Many thanks, PD Dr. Mumme, for your insights into regenerative cartilage therapy!
