Plastic plug postpones need for knee replacement
Approximately 600,000 people in the Netherlands suffer from damaged cartilage in their knees. A considerable proportion of them will develop osteoarthritis as a result and end up on the operating table for a full replacement of the joint.
This number can be drastically reduced if the damaged cartilage is replaced at an early stage by a synthetic mini-implant. The implant has been developed by Maastricht UMC+, DSM and TU Eindhoven, under the auspices of research institute Chemelot InSciTe and the company SyCap.
Alex Roth shows an animation of a knee in which a plug has been placed in the middle of the cartilage that forms the sliding surface between the thigh and lower leg. “You can see that there’s a missing piece of cartilage here. The plug, a mini-implant made of polymer, will replace it,” according to the biomedical engineer working at the Maastricht UMC+ Orthopedics department and involved in the SyCap project. “More specifically, the plug is made of polycarbonate urethane, a plastic developed by DSM that has a long track record of proven safety and wear-resistance. It has been used for years as a component in a variety of implants in the human body. We are now slowly moving towards the clinical phase and our hope is that surgeons will be able to use the plugs in clinical trials in 2023.”
Postponement A partnership between Maastricht UMC+, Technical University Eindhoven, DSM and the research institute Chemelot InSciTe, the SyCap project began in 2015. “The starting point was to find a solution that would make it possible to postpone the replacement of a damaged knee joint with a full prosthesis,” explains Dr. Pieter Emans, orthopedic surgeon and cartilage specialist at the MUMC+. “By repairing the damaged cartilage at an early stage using an implant, we hope to put a stop to the further degenerative process. You could compare it with filling a hole in the road with new asphalt before the hole just continues to get bigger. Metal implants are currently being used for the same purpose. However, the stiffness of the metal implants differs from cartilage to such an extent that the metal implants can actually inflict new damage on the cartilage. In the long run, this can happen as a result of slow loadbearing since the implant doesn’t have a shock-absorbing effect, or in the short term, if the implant hasn’t been positioned perfectly, causing part of it to protrude, for example. This is not the idea, of course.” Five years The expectation is that a plastic implant will be more flexible, and capable of restoring the cartilage’s shock-absorbing function. “And after five years of development and testing in the labs this expectation appears to be fulfilled,” Dr. Alex Roth continues. “We can’t say with any real precision right now, but the hope is that a plastic implant will be able to delay the development of osteoarthritis by at least five years. This is relevant, since it may mean that patients won’t even need a new knee or won’t need it for much longer at any rate. Normally, a knee replacement lasts ten to fifteen years. This is why doctors try to wait as long as possible before replacing a knee. Replacing a prosthesis is very invasive and can often lead to complications. This means a considerable increase in total costs.” The idea is that replacing a joint once in a lifetime is enough. “Exactly, but because people’s average life span continues to rise, we are seeing an increase in the number of revision total knee replacement surgeries. This is very taxing for the patient and expensive. If you can postpone an initial replacement by five or even ten years, this means major gains for the patient and health care expenditures.”
i-Med The step towards concrete applications in operating rooms is however still a big one. Inserting these implants also involves a high degree of precision. “We are now working with i-Med Technology (i-Med), the Technical University Eindhoven and IDEE, the instruments division of Maastricht UMC+, to develop an aid for surgeons. This involves a modified version of a surgical loupe that i-Med presented last January during the large CES technology trade show in Las Vegas. Weighing less than 250 grams, this device has two built-in HD cameras that surgeons and dentists wear on their heads while they perform surgery. Connected to a portable computer, this super-smart device not only shows exactly what the doctor is doing through precise and magnified images, but also displays 3D images of previously taken scans and photos and allows other relevant information to be retrieved via voice commands or with the foot console that is included with the device. “The intention is to provide the surgeon with support in the form of real-time 3D Augmented Reality navigation instructions, so that the plug can be implanted with a high degree of precision,” Roth says.
Valorisation SyCap is talking to interested investors about making the transition to the clinical phase. “Steps are currently being taken to set up a startup to valorise the idea. We’re very confident that this will be a success. Each year, Dutch healthcare insurers spend approximately 700 million Euros on knee replacements. SyCap can hopefully help reduce these costs considerably. It also spares patients the need to undergo major, risky procedures.”
