An interview with Medical Officer and co-founder Dr. Peter van Roermund

“No problem, do what you want,” said the first patient in the world to undergo knee joint distraction. Sixteen years later, he was still walking on his own knee. That was the start of further exploring the potential of Knee Joint Distraction.

Orthopaedic surgeon and inventor of Knee Joint Distraction, Dr. Peter van Roermund, has seen how in medicine, a decade of data can turn an idea into evidence. Those ten years have changed not just data, but lives.

What first made you consider Knee Joint Distraction?

It began with our experiences treating osteoarthritic ankle joints in the early 90s. We used an external device to gently separate both joint surfaces for three months, giving the unloaded cartilage a chance to repair itself. To our surprise, patients not only moved better but also kept their natural joints far longer than expected.

Around that time, a patient with painful osteoarthritis of the knee came to us. I told him we could try Knee Joint Distraction, explaining that he would be the first patient in the world. The results were remarkable: his pain decreased, he returned to work, and he managed to delay knee replacement for 16 years, from age 54 to 70.

This success showed the potential of Knee Joint Distraction for postponing knee replacement in younger patients, where revision rates are much higher than those over 65.

Afterwards, two police officers in their mid-50s also underwent the procedure. They wanted to avoid knee replacement and with it, a move to desk duty. One officer wore the distraction device for three months, the other for only two, yet both achieved comparable results. This led us to shorten the distraction period from three months to two. Based on continuing reliable results, we can now even reduce it to six weeks.

Over time, we expanded our studies across Europe. Slowly, people became familiar with the concept, and Knee Joint Distraction gained traction because of its clear benefit in delaying the need for knee replacement.

Today, with government funding of €10 million, a large randomized clinical trial is underway in more than ten hospitals in the Netherlands.

“To our surprise, patients not only moved better but also kept their natural joints far longer than expected.”

At what point did you decide to develop the KneeReviver®?

The first device we used for joint distraction was a huge and uncomfortable apparatus. The second one was more effective but still too heavy. So, we decided to design our own device, specifically for Knee Joint Distraction.

To develop the KneeReviver®, we partnered with BAAT Medical, a Dutch MedTech company specialized in developing innovative orthopaedic devices. This resulted in a device that patients and surgeons experience as more refined and practical.

How has Knee Joint Distraction evolved over the past ten years, and what does this decade of data mean for the future of knee preservation?

Orthopaedic surgeons today are much more aware of the risks associated with early knee replacement in young and active patients. Scientific publications and European orthopaedic registers show that younger patients (under 65) with osteoarthritis have a high lifetime risk of revision after their first knee replacement. Revision surgery is often complex, costly, and can be disabling.

Because knee implants have a limited lifespan, it is essential to postpone arthroplasty until an age where the implant will outlive the patient.

So far, 48% of patients treated with knee joint distraction still have their natural knee ten years or more after treatment, despite originally being candidates for knee replacement. The mean survival time is 7.2 years. These are truly remarkable results, which I am very proud of.

But it does not stop here. There is still much to discover: about the working mechanism, optimizing patient selection, and ways to improve the effect. A promising direction is combining distraction with other therapies such as cartilage cell culture, meniscus implants, or injections like corticosteroids or hyaluronic acid.

“The mean survival time is 7.2 years. These are truly remarkable results, which I am very proud of. ”

Do you see Knee Joint Distraction becoming part of daily orthopaedic practice in the next decade?

I believe it will be. There is a clear clinical need that Knee Joint Distraction fulfills: it offers surgeons an important OA joint-preserving alternative for their younger patients.

The technique itself is a standard orthopaedic-traumatologic procedure, already taught during training, which makes it accessible and easy to implement in practice. I am confident the technique will continue to gain traction, as osteoarthritis is projected to become the number one chronic disease by 2040. This makes the implementation of joint-preserving strategies even more urgent.

The major socio-economic burden caused by osteoarthritis can be addressed by applying cost-effective treatment like knee joint distraction. Moreover, the use of external fixation devices is already well-established in other orthopaedic applications, such as limb lengthening or fracture healing. That means the implementation of Knee Joint Distraction is straightforward; all orthopaedic surgeons are trained in these techniques.

Looking back, what has been the most rewarding part of this journey for you personally?

Well, of course that I am extremely famous… I am joking!

Some time ago, while walking through a public square in Amsterdam, a police officer approached me. It turned out he was one of my early Knee Joint Distraction patients, still actively serving more than twelve years later. Encounters like that give me great satisfaction. Knowing that what we did had a real impact, that he reached retirement with his own natural knee and was able to stay on active duty, is extremely rewarding.

On a scientific level, every surgeon is taught that cartilage cannot regenerate. The most exciting part has been proving that it can, contrary to long-held belief. The principle comes from demonstrating that controlled distraction stimulates tissue growth.

Using external forces to stimulate natural healing is a concept seen throughout orthopaedics, from scoliosis and hip dysplasia treatments to clubfoot correction. We applied this principle successfully to repair joints.

It reflects a broader truth in biology: mechanical forces shape growth and repair. This is symbolized in the emblem of orthopaedics, a curved tree tied to a stick, growing straight again. We simply guide nature; the body does the rest.