Stem Cell Research

Current cartilage replacement therapy is a time consuming, multi-step process that involves taking a cell culture from healthy cartilage, having them cultured and multiplied in a lab, and reinjecting them into the spot where cartilage is worn or missing.

The newly transplanted cells need to be supported in the body by animal collagens, which provide a sponge-like structure for the cultivated cartilage cells to grow on. Doctors usually use industrial-grade bovine collagen for this purpose.

The problems with this lengthy procedure -- known as ACT (autologous chondrocyte transplating) -- is that it requires several operations and is quite expensive. Simply the cost of having the cartilage cultured in a lab can run between 3,500 euros and 7,000 euros ($4,700 and $9,500)

Micro-fracturing and stem cells

Now, researchers at Lübeck University in northern Germany have developed a less-expensive and easier treatment, which is based on activating the body's own healing properties.

In the spot where the cartilage is worn out, a doctor bores tiny holes into the open bone -- a process called micro-fracturing. The bleeding from the bone marrow releases mesenchymal stem cells.

A sponge-like collagen frame, cut into the shape and size of the missing cartilage, is then inserted, and a little of the pateint's own blood serum -- which includes growth factor that can turn the masenchymal stem cells from the bleeding bone into cartilage cells -- is injected as well.

In the end, the patient'ss own cells attach to the sponge, and create a cartilage-like tissue. No externally grown cells are necessary.

Use of body's own powers

“What's funny about this matrix is that it creates a ceiling, and tissue or cells that grow underneath it, cling to it," said Peter Behrens, who developed the procedure at Lübeck University Clinic. "In this covered area, new tissue grows."

The new procedure, known as AMIC (autologous matrix induced chondrogenesis,) is being tested in clinics in Regensburg, Hanover, Freiburg and Potsdam.

“The stem cells are in our body," Beherens said. "That's what is fascinating about this method; we are activating our own cells."

There are stem cells everywhere in the human body, and people have known for years that bone marrow cells can be transplanted -- as is done with leukemia patients. Now they are being used for cartilage defects.

Replaceable 'asphalt'

To date, several hundred patients have had the procedure done successfully. Behrens comped the repaired cartilage to asphalt -- something that is good for a few years, but degrades over time and needs to be replaced.

"Our own cartilage is still the best, but this is a replacement that can help us be pain free for five years or so," Behrens said. "That is the whole idea of these procedures."

Behrens said he thinks it is OK that the solution is only for a few years, because the procedure can be repeated every few years. And if the patient wants to have prosthetic cartilage injected sometime instead, they can always still do so.