Current treatments have shown limited success in patching those damaged areas but now, a team at UCSF is taking part in a nationwide clinical trial with the goal of re-growing human cartilage to be implanted back into a patient's knee.
Ten years after tearing the cartilage in his knee, Michael Coats was facing the final option for his painfully deteriorated joint, a full knee replacement. "I'm thinking, 'I'm too young. I'm too active. I play sports. I coach my kids,'" he recalled.
Then, Coats learned about an experimental treatment that might allow surgeons to patch the chipped surface on his knee joint known as the "articular cartilage."
In a series of surgeries, doctors removed cartilage cells from his knee then cultured them using a kind of three-dimensional frame, to grow a natural piece of cartilage.
Benjamin Ma, a surgeon at UCSF in San Francisco, is participating in the nationwide trial.
"We can actually biopsy cartilage cells from the body, grow them in a lab and then implant into a scaffold, giving them a house they can live in," he explained. "Once they live in there they grow cartilage, or protoliken, which is the structure of what cartilage is and now you have a piece of cartilage you can implant back into the body where the defective cartilage is."
Coats, who had his surgery performed at Duke University, has been pain free for more than a year.
"So far, so good. No pain to walk. I can go up stairs. I can go downstairs. I can go up hills without pain, whereas before, it was always severe pain, sharp shooting pain," he said.
Ma says he has also achieved promising results in the surgical trial at UCSF. The procedure is an alternative to microfracture, where surgeons create a hairline break in the damaged area and try to coax a scar tissue version of the cartilage to grow back in. But, Ma says the result rarely duplicates the joint's articular coating.
"The two surface, when they rub together, are smoother than anything we can make with human hands, better than ceramic, better than metal, better than ball bearings… But, that's what we're trying to duplicate," he explained.
Ma says the procedure takes about 10 weeks to complete, with several months of recovery time after that.
The scaffolding used in the procedure is manufactured by a firm on the east coast under the name Neocart. One note, the replacement technique is designed to repair damage to an otherwise healthy knee, but not natural deterioration from age, commonly known as osteroarthritus.