Stem cells are both in and out. It was once thought that if these cells were injected into joints, they would turn into cartilage. Two problems arose. First, patients (unless they are infants) have very few stem cells left. Second, the injected cells died after releasing their instructional growth factors, never turning into cartilage. But what we have learned is that an increasing number of concentrated growth factors, immune stimulants, and even some drugs can induce the migration of the body’s own progenitor cells—some of them stem cells—cells that direct healing—to the injured area. These cells then optimize the environment around the injury to effect healing.

The ACL is the key stabilizer of the knee and is torn 300,000 times a year in the U.S. alone. The treatment of these torn ligaments has evolved in some ways, but not so much in others. Here is what we know today.

Artificial knee replacement surgery used to mean the reduction of sports activities like golf, swimming, and cycling. Yet with severe arthritis affecting younger and younger people, we are currently pushing the envelope of sports participation with joint replacements and learning as we go.

Arthritis is preventable. Yet until recently most people thought it was inevitable. Here are some examples of how to best treat your injured knee.

How a biological device can act as a trellis for new meniscus tissue to grow into, reconstructing missing segments of the meniscus shape.

Don’t give up on your knee. Even if you had your meniscus cartilage removed, even if you have developed osteoarthritis and can barely walk without pain, there is still a chance that your knee can be restored. This study confirms how.

If we live longer, will our joints still work? While many diseases can kill you, arthritis has the potential to ruin your long life.

When skiing superstar Lindsey Vonn recently announced her withdrawal from the Winter Olympics, she demonstrated that reconstructing the torn anterior cruciate ligament of a world-class athlete has its unique problems.

A recent study suggested that meniscus surgery doesn't help. Studies can be misleading. Even small losses of meniscus tissue lead to big changes in force concentration on the tibia (shin bone) and eventually arthritis.

We like to do everything possible to rebuild the knee joint with biologic tissues rather than artificial materials to help delay the time in which an artificial joint replacement is necessary.

Knees do not necessarily wear out evenly, sometimes one part of the knee is perfectly fine while another part is completely destroyed. If only part of the knee joint is worn out, why replace all of it?

How often do you stop to think about the miraculous self-healing machine that is your body?