American Way Magazine—January 31, 2013
Derek Johnson didn't give much thought to the protective cartilage that cushioned his bones until a small area in his left knee wore down to the point that it was raw and painful. Following an evening on the basketball court, the 44-year-old woke up in the morning and knew he was in trouble: "I could barely walk," he says.
After babying the joint and consulting with an orthopedic surgeon, Johnson dialed back his physical activity for several years -- no competitive basketball and more "timid" tennis and football sessions, as he describes it. But the pain flared up again last summer . Johnson returned to his surgeon at New York City's Hospital for Special Surgery (HSS) and learned that his once tiny area of cartilage loss was expanding. Soon thereafter, the 49-year-old father of two opted to try an experimental procedure -- one that would use his own harvested cartilage cells to grow a new protective layer of tissue.
With limited cartilage-regeneration options available, Johnson believed this technique represented his best hope of one day resuming his sports passions. "I wasn’t prepared -- or willing -- to become victim to a constrained way of life," he says.
The procedure, in which harvested cells grow along a three-dimensional scaffold-like collagen device called a NeoCart, is one of several cartilage-regeneration approaches being explored by researchers in the United States and elsewhere who are striving to find a simple and cost-effective solution for a common problem: limited but painful cartilage loss in the knee. The NeoCart approach is focused on growing new articular cartilage, the layer of tissue that covers the ends of long bones in the joints.
For active people who, like Johnson, are decades from retirement, the loss of even a small area of articular cartilage can be emotionally and physically debilitating. "I call it musculoskeletal depression," says Riley J. Williams III, MD, Johnson's surgeon.
As it turns out, articular cartilage is a remarkably complex tissue, one that's difficult to repair or replicate. It's designed to provide a hard and resilient shield that prevents the ends of bones from rubbing against each other. Thus, cartilage lacks the nerves and blood vessels found in many other parts of the body. That's good in some respects, says Dr. Williams, director of the HSS Institute for Cartilage Repair, because “otherwise, every time you jumped, fell, or twisted, you would be in excruciating pain."
But the tissue's restorative abilities suffer. "It's not like bone. It's not like skin. It's not like the liver," he says. "Cartilage has such a poor capacity for repair that injuries are devastating unless you can go in and do something to fix it."
Johnson had two surgeries. The first was to remove a tablet-size piece of cartilage from a non-weight-bearing area of his left knee.
Six weeks after his second surgery, during which the engineered tissue was implanted, Johnson was walking fine -- with the exception of descending stairs. And according to Johnson, Dr. Williams "is rather bullish that come spring, I will have my full range of motion and mobility back." Johnson, eager to tear up the basketball court again, hopes that the procedure will provide more durable and longer-lasting cartilage than the traditional microfracture technique. "I'd love to ride this knee out with just this one procedure," he says.