New ways to heal knees

January 8, 2009 9:03:12 PM PST
Twenty one million Americans live with some kind of joint pain that makes everyday jobs excruciating.But surgeons are racing to find better ways to fix damaged knee cartilage.

Whether it's from overuse or injury, the loss of cartilage around the knee is a painful ordeal.

For most people a knee replacement is a good solution. But many younger patients want a more natural fix.

Cartilage replacement is seen as the answer. It's a treatment with many limits but scientists say big changes are coming.

Insurance executive John Golden was captured on video as he summits a 22,000 foot peak in the Himalayan Mountains.

What makes John's accomplishment so amazing is that he was once told his knee pain would keep him grounded forever.

An old college football injury messed up John's knees. By his late 30's, the cartilage was destroyed.

John wasn't ready for knee replacement. So he found Dr. Brain Cole at Rush University Medical Center who does cartilage replacement.

"We're taking either someone else's tissue or utilizing the patient's own tissue," said Dr. Brian J. Cole, orthopedic surgeon, Rush University Medical Center.

The best patients for cartilage replacement tend to be younger than 50 with limited damage and do not have widespread arthritis.

In one technique a few cells are taken from a patient's knee or another part of the body and are grown in a lab. Those cells are then implanted back in the knee and should multiply, filling in the damaged area.

"There's actual real healing that goes on to incorporate that tissue," said Cole.

In another version, cartilage from a cadaver is harvested and implanted. The implant can include both bone and cartilage but the downside is there may be some risk of infection.

But even as these techniques evolve lab grown cartilage still isn't consider by many to be as good as the original. Scientists are furiously looking for a better way.

"We've developed a material that serves as a baind-aid that can be put in the place of the degenerated cartilage," said Thomas Webster, Ph.D., biomedical engineer, Brown University.

At Brown University, scientists are trying a different approach. They're using carbon nanotubes, tiny, strong fibers that have a rough surface to attract cartilage growing cells. When a person walks the pressure on the tubes generates electricity, triggering the cells to grow cartilage.

But this technique is still experimental and years away from reality.

"Like everything else in life there is no quick fix," said Dr. David Manning, University of Chicago Medical Center.

At the University of Chicago Medical Center, surgeons are not currently doing cartilage replacement.

Dr. Manning believes better techniques are coming but for now does not see this as a good option.

"Most of the folks that show up with knee pain who are adults actually have a more degenerative nature to their knees and are not candidates for that procedure," said Dr. Manning.

But, John's younger age and lack of arthritis made him good candidate. The surgery involved not just cartilage cells from a cadaver. But he also received an entire meniscus, the cushioning on either side of the joint.

Amazed by his patients progress, Dr. Cole wanted to see John in action. The two climbed Mount Shuksan in Washington state together.

"I went in thinking I was going to get a knee transplant and what it did was really reinvigorate my who body - my whole being," said Golden.

Another more common procedure called microfracture where tiny fractures are made in the bone to encourage the development of new cartilage is favored by some doctors over cell transplants.

Researchers say a newer generation of cartilage replacement will soon be tested in the United States. Several companies are now competing to improve the type of cell that is grown for cartilage repair.

Dr. Brian Cole
Rush University Medical Center
Midwest Orthopedics

Dr. David Manning
University of Chicago Medical Center
5841 S. Maryland Avenue, MC 3079
Chicago, IL 60637
(773) 702-6216

Thomas Webster, Ph.D.
Biomedical Engineer
Brown University

American Academy of Orthopaedic Surgeons