The human knee is one of the most vulnerable joints in the body, particularly among men and women who participate in athletic activities. A recent report noted that more than one million people suffer meniscal tears annually in the U.S. and Europe alone. These injuries are particularly common in sports such as football, soccer and rugby.

More than 90 percent of these tears occur in the “white zone” of the meniscus, which is often do not to heal due to its low blood supply. As a result, many professional sports players opt to have the torn tissue removed altogether, risking osteoarthritis in later life.

However, new research in Europe has suggested using the patient’s own stem cells as a type of “cell bandage” to encourage healing of the affected tissue. Dr. James Walter a participating physician with the Texas Health Spine & Orthopedic Center referral line and the medical director for FC Dallas, the Major League Soccer team in North Texas, was asked his opinion about this new treatment for knee injuries.

What is a Meniscal Tear?

The meniscus is part of the supporting structure of the knee, located between the primary bones of the leg—the femur and the tibia.

“In engineering terms, the meniscus acts as a type of ‘O-ring,’” said Dr. Walter. “It adds an extra cushion for the knee, and it is required for the knee to have normal function.

“Unfortunately, these structures are prone to tearing when they are subjected to the stress of sporting activities. This can cause pain, dysfunction and the inability to play.

“Meniscal injuries can happen any time there is a torque or twist of the knee. If someone is jogging or even sprinting, they are moving straight ahead and there is not a great deal of twisting of the knee. However, in sports like soccer, basketball, tennis or football, where athletes are turning or ‘cutting’ quickly, this is where the meniscus can be torn.”

Conventional Treatment for This Condition

When a meniscus tear is small and essentially asymptomatic, an athlete can undertake a physical rehabilitation program to re-build strength in the knee. Often, this is enough to get the athlete back on the field.

“However, if these tears are symptomatic and they don’t respond to conservative treatment, it is necessary for surgical treatment to remove the damaged meniscal tissue,” said Dr. Walter. “This is currently done in a minimally invasive way, using arthroscopic surgery. This surgery takes about twenty minutes, and we attempt to leave the undamaged meniscus tissue in place.

“Unfortunately, we have learned that a patient who has had the entire meniscus removed is at high risk of developing osteoarthritis and will likely require a knee replacement in the future.”

Using Stem Cells as a Living Bandage

Using a person’s own stem cells in the treatment of injuries has gained a great, albeit somewhat controversial, enthusiasm among orthopedic specialists. Dr. Walter is intrigued about this treatment.

“In theory, this treatment seems very logical,” he said. “The white zone of the meniscus is poorly supplied with blood flow, and any tissue that is not getting an adequate supply of blood will have difficulty healing. This results in surgeons removing most or all of the meniscus tissue because it does not have the capacity to heal adequately in most instances.

“There is a great deal of interest in stem cell treatment for these types of injuries because they allow for the possibility of building new tissue naturally. Using stem cells in the meniscus could allow us to harness the healing capacity of stem cells after we have surgically repaired these injuries.

“It’s very exciting,” Dr. Walter concluded. “However, we are very early in the experimental process.”