Tendon Injuries May Soon Be Repaired with Tendon Stem Cells

Our bones are supported by a combination of muscles and tendons; tendons connect muscles to bones. Ligaments are similar structures, but they attach bone to bone.

A tendon strain results from an injury to either a muscle or a tendon, usually in a foot or leg. A strain may be a simple stretch in the muscle or tendon, or it may be a partial or complete tear in the muscle-tendon combination. When there's a tear, surgical repair is often necessary. However, as many a professional athlete knows, injured or damaged tendon tissue heals slowly and rarely regains its pre-injury integrity or normal strength. That may soon be changing, however.

On Sept. 7, a University of Southern California (USC) press release announced that USC School of Dentistry researcher Songtao Shi, along with other scientists, has found promise for treating tendon injuries. Using animal models, Shi and his colleagues have identified unique cells within the adult tendon that have stem cell characteristics. The isolated cells proliferate tendon-like tissue that can be used to repair damaged or injured tendons.

Explaining the significance of the findings, Shi said: "Clinically, tendon injury is a difficult one to treat, not only for athletes but for patients who suffer from tendinopathy such as tendon rupture or ectopic ossification. This research demonstrates that we can use stem cells to repair tendons. We now know how to collect them from tissue and how to control their formation into tendon cells."

According to Tendinosis.org, workplace and sports injuries constitute the majority of tendon strains and injuries. Most tendon strains or tendon damage are the result of repetitive motion, as opposed to acute injuries. It's also been said that 30-50 percent of all sports injuries, whether that be professional or amateur sports, are the result of overuse tendon injuries.

Tendinosis.org says that normal, healthy tendons consist of collagen. The USC release describes tendons as "specialized tissues" that are made up of "strong collagen fibrils that transmit force allowing the body to move." When a tendon is damaged or strained, some of the collagen is injured and breaks down. The body attempts to heal the tendon, but chronic overuse injuries don't heal well because the body's fibroblasts produce abnormal tendon and ligament collagen.

Prior to the research at USC, little information existed on the cellular makeup of tendons and their precursors. However, in examining tendons at the molecular level, Shi and his research team identified a unique cell population. Dubbed "tendon stem/progenitor cells" in both mice and adult humans, they can be formed into tendon cells. The promise this holds for those who suffer debilitating tendon damage or injury is significant.

Dr. Shi has published several studies on the role of stem cells in regeneration. The results of this latest research project will be published in the October 2007 issue of the "Nature Medicine" journal.

Sources:

Press release, Researcher Identifies Stem Cells In Tendons That Regenerate Tissue; http://www.newswise.com/articles/view/533164/

Tendinosis.org; http://www.tendinosis.org/