AAOS Now

Published 8/1/2010

ACL injury prevention: Does it work?

Study calls for more research on ACL, knee injury prevention programs

How effective are prevention programs for knee injuries in young athletes? According to a study presented at the American Orthopaedic Society for Sports Medicine (AOSSM) annual meeting, better designed research studies are needed before it can be concluded that specialized training programs can prevent injuries to the anterior cruciate ligament (ACL) and the knee.

“Evidence shows that injury prevention programs may reduce the risk of some knee injuries, but additional research is necessary,” said Kevin G. Shea, MD. “Questions about the efficacy of some exercise/training programs exist and additional well-designed research studies are needed before we can definitively prove the value of these programs.”

An estimated 200,000 ACL injuries occur annually in the United States, according to the American Journal of Sports Medicine. Approximately 15 percent of all sports injuries involve the knee.

Dr. Shea and his coauthors searched for ACL/knee injury prevention program studies in three medical databases. Then, using a “quality of evidence” ranking algorithm, the authors evaluated the studies, and found 15 that met their research criteria.

None of the studies provided Level I (randomized, prospective) evidence; 12 provided Level II (nonrandomized, prospective) evidence, and 3 provided Level III (case-controlled) evidence.

Of the 15 studies, 9 demonstrated a reduction of knee or ACL injury. Of the 13 studies that looked at ACL injury specifically, 5 studies demonstrated a reduction of ACL injury. Careful review of these studies, however, showed that many contained design flaws that introduced bias into the results, which raised questions about the effectiveness of some injury prevention programs.

“We do not have the highest quality research designs showing us that preventive training programs can reduce knee or ACL injuries,” said Dr. Shea. “That doesn’t mean that these training programs do not help; I encourage my own children and my patients to do these exercises, because the existing evidence suggests they have some benefits.

“But, we need better research evidence that confirms the effectiveness of injury prevention programs,” he continued. “The sports medicine community should continue research in this area, including high quality clinical trials.”

Dr. Shea’s coauthors for “ACL and Knee Injury Prevention Programs for Young Athletes: Do they Work?” include Nathan L. Grimm, BS; John C. Jacobs, BS; and Shawn Simonson, EdD, MS. The authors report no conflicts.