Building a better knee

Patients must wait until the knee degenerates to justify the replacement and there's always the risk that the body will reject the foreign object. Dr. Kandel and her team are developing a substitute knee replacement that combines cartilage engineered in the lab with a degradable porous biomaterial that functions like bone. When implanted, the bone gradually grows through the porous holes while the biomaterial biodegrades - leaving a functioning, natural joint.

The advantages are manifold. This approach can be used for localized damage as soon as a defect is identified, or as a knee replacement when the damage is more diffuse. The replacement is natural, not artificial. And, says Dr. Kandel, the biomaterial can be shaped and customized to fit each recipient's knee, rather than using an "off-the-shelf" prosthesis. Once perfected, the technique will be applicable to other joints such as hips, shoulders and elbows. This means fewer people could be waiting for conventional joint replacements, resulting in shrinking waiting lists.

There's still a long way to go to make the new technique a reality. Developing cell sources to form the tissue and shaping and machining techniques to customize the replacement are just two areas Dr. Kandel's team of engineers, cell biologists, surgeons, radiologists and veterinarians are addressing.

"It is so important to have all these different perspectives to facilitate the development of this approach into a clinical treatment," says Dr. Kandel.