After an ACL tear: Research opens door to new treatments to improve recovery for athletes

A U-M clinical research coordinator conducts functional knee strength testing at the U-M Health System's MedSport facility to measure muscle weakness after an ACL injury. Credit: University of Michigan Health System

Striking the likes of Chicago Bulls' Derrick Rose, L.A. Lakers' Kobe Bryant and Detroit Tigers' Victor Martinez, tears in the anterior cruciate ligament (ACL) are one of the most rampant and serious knee injuries among athletes.

Now, researchers from the University of Michigan Health System have identified a new that may prevent one of the most dreaded consequences of an ACL tear –the weakening or loss of muscle tissue (muscle atrophy) that can be a career-killer in sports and ultimately develop into osteoarthritis.

A hormone called myostatin that blocks muscle growth appears to play a key role in causing after ACL tears, according to a study that appears in the American Journal of Sports Medicine. The findings pave the way for potential treatment preventing after an ACL tear and consequent knee replacement, which affects more than 250,000 people a year in the U.S.

"We've had several advances in technology to improve the recovery process for an ACL tear, but most patients still experience 30-40 percent muscle weakness – and that weakness largely limits the ability to return to the same level of sports," says lead author and athletic trainer Christopher L. Mendias, Ph.D., A.T.C, assistant professor of Orthopaedic Surgery and Molecular & Integrative Physiology at the U-M Medical School.

"This is the first study in humans to open the door to a potential therapy to prevent . We see this as an important step in restoring athletic and functional abilities in the short term, and in preventing osteoarthritis in the long term."

Often dubbed an athlete's worst nightmare, usually require surgical repairs and months of intense rehabilitation that force long breaks from playing any sports.

Myostatin has shown promise as a potential drug target for treating other conditions such as muscular dystrophy and cancer, and blocking the protein has led to increased muscle mass and strength.

"In the sports world, there's great concern about the short-term and long-term affect of an ACL tear on not only an athlete's physical skills and ability to return to play, but also the longevity and health of the knee joint," says senior author Asheesh Bedi, M.D., assistant professor in orthopedic surgery.

"This is the first study to look into the biology of muscle tissue involved in an ACL tear and to show how Myostatin affects the muscle damage we see following surgery. We need further studies to examine how these findings may aid in better recoveries following a common and often detrimental type of knee injury for athletes."

More information: "Changes in Circulating Biomarkers of Muscle Atrophy, Inflammation and Cartilage Turnover in Patients Undergoing Anterior Cruciate Ligament Reconstruction and Rehabilitation," American Journal of Sports Medicine, DOI:10.1177/0363546513490651

add to favorites email to friend print save as pdf

Related Stories

AMSSM: Autologous stem cells show promise for ACL tears

Apr 20, 2013

(HealthDay)—For patients with partial or complete non-retracted anterior cruciate ligament (ACL) tears, injection of autologous mesenchymal stem cells directly into the ACL sheath may help heal the tear, ...

Battle of the sexes: Who wins (or loses) in ACL ruptures?

Jan 08, 2013

Female athletes are three times more likely to suffer from anterior cruciate ligament (ACL) ruptures, one of the most common knee injuries, compared to male athletes. The ACL is one of the four main ligaments within the knee ...

Recommended for you

The hunt for botanicals

Dec 19, 2014

Herbal medicine can be a double-edged sword and should be more rigorously investigated for both its beneficial and harmful effects, say researchers writing in a special supplement of Science.

Mozambique decriminalises abortion to stem maternal deaths

Dec 19, 2014

Mozambique has passed a law permitting women to terminate unwanted pregnancies under specified conditions, a move hailed by activists in a country where clandestine abortions account for a large number of maternal deaths.

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.