IMPACT study
A knee cartilage treatment that is less stressful for the patient - that is the aim of the IMPACT trial in the Mobility Clinic at UMC Utrecht. Usually, two surgeries are required for cartilage problems in the knee: one to take patient cells for culture in the lab, and a second to place the cells back into the knee. Thanks to a multidisciplinary collaboration of doctors, biologists, physiotherapists and orthopedic surgeons, this can now be done in one single surgery.
What is Cartilage?
Cartilage is a rubbery tissue that covers the ends of our bones inside joints. It ensures smooth movement when we walk, run or bend. If the cartilage is damaged, rough bone surfaces move against each other and start to chafe. This causes pain, swelling and stiffness. Over time, this can lead to long-term disability and osteoarthritis.
The challenge in repairing cartilage
Cartilage injuries in the knee (articular cartilage) are particularly difficult to treat because the tissue has a poor ability to repair itself. For many years, the most advanced option available has been ‘autologous chondrocyte implantation’, a treatment where a patient’s own cartilage cell are harvested in a first surgery, expanded in the lab and then reimplanted in a second surgery. Although this technique has achieved good results, it is a costly and extensive two step procedure. It is also limited by the number of cells that can be obtained and by the changes (dedifferentiation) the cells undergo during expansion.
The IMPACT study: a new approach
The IMPACT study is changing that story. Researchers, including Daniël Saris, Lucienne Vonk, Jasmijn Korpershoek and Roel Custers, have developed a one-step surgery designed to help repair knee cartilage more efficiently, and with less trauma than traditional treatments. This approach aims to improve logistics and cost-effectiveness, while improving clinical outcome. For more details about the procedure, watch the video.
How does IMPACT work?
During the one-step surgery, a small sample of the patient’s own cartilage is combined with special cells from a donor, called mesenchymal stromal cells (MSCs). These cells release natural signals that act as a “trigger,” encouraging the patient’s own cartilage cells to regrow cartilage tissue. Over time, the patient’s cells spread across the damaged area and produce new cartilage tissue, restoring the joint surface. While the new cartilage can take up to one or two years to fully form, patients often experience less pain and improved joint function much sooner. This allows them to start rehabilitation faster compared to traditional treatments.
Good results
In the first clinical trial, 35 patients received the treatment, and the results were encouraging: it was safe, feasible, and improved joint function. After one year, the cartilage looked healed on video surgery (arthroscopy) and sample tests (biopsies) confirmed that the damaged area was filled with the patient’s own cartilage cells. “Looking back at the first study, patients have now been followed for 10 years, and the majority continue to show excellent healing and joint function”, Jasmijn shares. For patients like Kevin, the difference is life-changing. After his IMPACT procedure in the first clinical trial, he got back on track. Watch the video (Dutch).
Building on the success of the first IMPACT study, the team launched IMPACT2, which is now almost complete. This time, 60 patients participated. The researchers compared clinical outcomes of patients receiving the IMPACT procedure to patients receiving standard care for 9 months, consisting of optional physical therapy and pain medication. After 9 months, the control group was also offered to receive IMPACT. “Results are very promising, showing good clinical outcomes”, says Jasmijn. IMPACT2 is set to finish in 2025.
For more information, please refer to the official website of UMC Utrecht (Dutch) or clinicaltrials.gov