Newswise — Each year, millions of people undergo surgery to repair damaged cartilage in their knees. Unfortunately, in most of those cases, doctors simply remove the damaged cartilage and leave nothing in its place, nearly ensuring that patients will experience painful arthritis as they age. However, a process developed by a University of Missouri-Columbia researcher that has received FDA approval recently, helps the knee to generate cartilage without the use of drugs.

One common cause of osteoarthritis, the most common form of arthritis, occurs when an area of knee cartilage is damaged and must be removed during surgery. The cartilage, known as the meniscus, is a shock absorber in the knee. When torn or damaged, the meniscus typically does not heal on its own, and the damaged portion is removed and not replaced. While current surgical techniques solve the short-term problem, osteoarthritis inevitably develops several years later. James Cook, an MU professor of veterinary medicine and surgery, has performed groundbreaking research for DePuy Orthopaedics Inc. to help develop a process that successfully encourages the meniscus to repair itself, while minimizing progression of osteoarthritis for the patient.

"Other studies have shown the amount of arthritis a person experiences is related to the amount of meniscus you have left in your knee," Cook said. "In our animal studies, we have been able to grow back 90 percent of the meniscus on average. Using tissue engineering and biological stimulation through the implantation of a scaffold derived from pig intestines, we show the tissue where it needs to grow. With approval from the federal government, we will now be able to begin using this in humans in the first phase of clinical trials."

While the new process has been used in more than 300 dogs, about 20 human patients will receive the procedure in the trials, which will be completed by surgeons in Memphis and Indianapolis. Following a successful first phase, the trials will be opened nationwide for a second, larger trial before finally being available to the public. Cook expects that process to take about 3-6 years. Ideal patients for the trials are those individuals who are in good health, but are suffering from a meniscal tear that will extend to the vascular zone of the meniscus when surgically treated.

However, the surgery is not limited to new injuries. Cook believes in select cases the procedure might help older adults who experienced damaged knees years before. In addition, there have been no major side effects reported from implantation of the scaffold. Currently, the implants are being used in rotator cuff injuries, skin grafts and bladder reconstruction in humans.