Stem Cell Research Reveals Insight into Repair of ACL Tears


Kevin Baker, a director of orthopedic research at Beaumont Health, and Dr. Kyle Anderson, an orthopedic surgeon, today announced a study that reveals injuries, including a torn ACL, can summon armies of stem cells. Stem cell’s importance comes from their ability to develop into any other type of cell, including muscle, bone, or nerve cells. Prior to this study, scientists only knew that stem cells were summoned to the heart and brain during a heart attack or stroke to keep the body alive.

The study entitled, “Acute mobilization and migration of bone marrow-derived stem cells following anterior cruciate ligament rupture,” reveals that when the stem cells arrive to regenerate and repair the torn ACL they cannot penetrate the thick membrane surrounding the knee joint.

“We think this discovery will help us to understand how the body responds to an ACL injury, and also how post-traumatic osteoarthritis develops after a joint injury,” says Dr. Anderson.

Post-traumatic osteoarthritis, a form of arthritis that develops after a knee injury, commonly affects veterans, athletes and others who regularly put stress and strain on their knees. According to the Centers for Disease Control and Prevention, osteoarthritis affects more than 30 million adults in the United States, with many of these cases occurring after trauma to a joint. It is also a leading cause of disability. Baker and Dr. Anderson’s findings begin to reveal how the body tries to heal these injuries.

Baker adds that stem cell levels generally decline as the body ages.

“This could explain why your knee joint doesn’t heal as well after a trauma when you are older. The next step of our research will be finding methods to get the stem cells inside the joint. If the stem cells can get through the membrane around the knee, they could help speed up the healing process and perhaps delay or prevent arthritis.”

The study was funded in part by the American Orthopedic Society of Sports Medicine. It will be featured in an upcoming edition of the journal, Osteoarthritis and Cartilage. Other members of the research team include Dr. Perry Altman, Dr. Asheesh Bedi, and Tristan Maerz, of the University of Michigan.