Lab-Grown Cartilage Could Repair Damaged Knees

A procedure called Carticel involves removing a small portion of non-weight-bearing cartilage from the healthy knee, allowing the cells to reproduce and implanting them back into the damaged knee.

The procedure is for patients with localized damage to the knee cartilage, not those with arthritic knee problems. It's approved only for knee surgery, but experimental trials show some promise for ankles, hips and shoulders.

Holly Clausen, who injured her knee during a head-on collision six years ago, underwent a Carticel procedure after other attempts to repair her damaged knee failed.

"I couldn't do anything without pain. I mean, I could never bend my knee," she said.

Duke University orthopedic surgeon Dr. Alison Toth said Clausen lost an entire piece of cartilage, which left her femur rubbing up against her kneecap.

"I would describe that to patients as a pot hole," Toth said.

In the Carticel procedure, Toth removed a piece of cartilage from Clausen's other knee and sent it to a Boston lab.

"They grew her own cells until they had many millions of cells from her," she said.

A month later, Toth implanted the new cells. She made a large incision to expose the knee joint, removed a patch of bone lining from the tibia and sewed it over the damaged patch of knee cartilage. The solution of cartilage cells was then injected under the sewn patch and sealed in place.

"It really takes a full year for those cells to make enough cartilage to be firm like normal cartilage," Toth said.

Clausen's leg was immobilized in a constant passive motion machine after surgery to help the new cells mature properly, gel in place and eventually harden.

Although she doesn't look forward to the long recovery period, she's focused on the end result.

"(I like) knowing that it would be a permanent result as opposed to having artificial parts," she said.