Cartilage Registry: "We generate fully independent data"

Interview with Prof. Philipp Niemeyer, DGOU Clinical Tissue Regeneration Study Group; Section Head of Cartilage Surgery at the Clinic for Orthopedics and Trauma Surgery

Does a patient benefit from treatment or not? How many patients are being treated as a result of damaged cartilage in the knee joint? What intervention is performed most frequently?


Photo: Prof. Philipp Niemeyer

Prof. Philipp Niemeyer; © Freiburg University Hospital

These and other questions are meant to be answered in the future with the help of a new Cartilage Registry, which was created by the German Society for Orthopedics and Trauma Surgery (in German: Deutsche Gesellschaft für Orthopädie und Unfallchirurgie) in October of 2013. spoke with Professor Philipp Niemeyer, co-founder of the DGOU Cartilage Registry (in German: KnorpelRegister DGOU).

The Cartilage Registry is almost one and a half years old, so it is still in its infancy. Why is it the first of its kind in this form?

Philipp Niemeyer: You might say that registry studies are just now gaining in importance in Germany. This is different in Scandinavian countries. When it comes to endoprosthesis or the field of cruciate ligament injuries for example, physicians and researchers in those countries have had many years of experience with these types of registries. However, we are a global leader in the field of cartilage registries! This is the first initiative that is facing the demands of health services and evidence-based research in this way. We are supported in this by the German Osteoarthritis Support Organization (in German: Deutsche Arthrose-Hilfe e.V.) and the Oskar-Helene-Heim Foundation (in German: Stiftung Oskar-Helene-Heim), which neutrally fund the project. Our project is entirely independent from the industry, since it originated with the Clinical Tissue Regeneration Study Group (in German: AG Klinische Geweberegeneration) by the German Society for Orthopedics and Trauma Surgery. If you take a look at the current scientific literature, frequently individual surgical and treatment techniques such as medical devices and pharmaceutical products are being featured, subsequently making strong industrial backup or sponsoring available. This is not the case with us. We generate fully independent data.

Who has insight to this data?

Niemeyer: It is not a public interest registry where every person is able to look at individual case documents. Yet more than 60 clinical facilities are participating in the registry and collect their patient data with us. From this group, scientific evaluations are prepared for publications, which are in turn included in scientific literature. This means, the findings of the Cartilage Registry will essentially be reported worldwide and people can get information based on these publications.

What is the impact of this data?

Niemeyer: We are hoping to improve patient safety based on this data. We would like to be able to provide more accurate information on the complication rates of certain techniques for example. We also hope to prove the effectiveness of cartilage surgeries. In addition, as physicians, we want to know what technique and treatment was most successful with which patient. So far, we do not have enough data for this yet. This is why we first prepared a publication that is intended to publically promote the idea of the Cartilage Registry. It mentions current patient care data for example. Needless to say, we are interested in medium-term results of treatments, meaning the function of the joint after one, two and five years. For the first time, we now have patient data one year after treatment. The first conclusive publications will therefore be issued at the end of 2015.

How can the Cartilage Registry help the attending physician?

Niemeyer: He or she can look at the data to assess what procedure is the most promising for certain indications. He or she can subsequently use this as a foundation during consultation and diagnostic evaluation for patients with cartilage damage.

What intervention is the most frequent entry?

Niemeyer: Cartilage surgeries are roughly divided in two different categories. On the one hand are transplantation techniques where cartilage tissue from a healthy part of the body is transplanted into a defect area or chondrocytes are extracted from the patient to grow and replace them. The second group includes bone marrow stimulating techniques where a targeted injury is generated at the defect location to induce scar tissue.

When you look at corresponding survey data, bone marrow stimulating techniques are globally the most frequently used interventions. This is reflected in the Cartilage Registry. The best-known technique here is “arthroscopic microfracture surgery“, which is also represented by the largest patient percentage in the Cartilage Registry. This is followed by autologous chondrocyte transplantations – that being the treatment of cartilage damage with the patient’s own chondrocytes cultivated in the laboratory -, which is traditionally a very popular procedure in Germany.
Photo: Knee operation

The register for example includes which cartilage operations in the knee occur most frequently; © Cap

How is patient data being protected?

Niemeyer: Essentially, data is being entered in anonymized form. Only the physician, who enters the data into the system, knows the real name of the patient. Only non-personal case characteristics are being centrally stored. That is to say, the moment the data arrives at the central server of the University of Freiburg’s data processing center, we only identify the patient as a number with disease and therapy-specific characteristics.

What happens if you want to access the real names again? Could you do that?

Niemeyer: If you want to retrace a case number back to a patient, you could do so anytime through the attending physician in the Center, because he or she is the only one, who knows and documents the cartilage identification number and the personal data.

Which registries are still to come?

Niemeyer: We started with the registry for cartilage defects of the knee, because the knee represents the most common site for cartilage defects. In October of 2014, we added modules for the hip and ankle joints, which run for four months. We are also planning a module for the shoulder joint in 2016. Whether more modules will follow is currently not certain yet. 

Photo: Simone Ernst; Copyright: B. Frommann

© B. Frommann

The interview was conducted by Simone Ernst and translated by Elena O'Meara.