Vavken and coauthors have performed a systematic literature review and meta-analysis of a timely topic. The issue of anterior cruciate ligament (ACL) injury prevention strategies continues to become increasingly important. One of the first questions that patients ask once they have been diagnosed with an ACL tear is, “Could I have prevented this?” The importance of prevention continues to be borne out in the ACL literature. Our recent systematic review in JBJS demonstrated that, at a minimum follow-up of five years after ACL reconstruction, the risk of sustaining an ACL tear in the contralateral knee is 11.8% compared with a 5.8% risk of a repeat ACL tear in the reconstructed knee1. Obviously, preventing these injuries would decrease health-care costs and decrease these patients’ risk of future osteoarthritis and limited activity.
The authors’ stated goals for the present literature review were to determine whether currently practiced prevention therapies decrease the risk of ACL injuries, to identify the best prevention program, and to assess the validity of the review's findings. As is the case in many areas of orthopaedics, the included studies were not homogeneous and had a variety of levels of evidence.
The effectiveness of the injury prevention programs was reported by a variety of methods in the included studies. The authors of the review pooled the ACL injury rates and calculated an overall risk ratio of 0.38, corresponding to a 62% decrease in the risk of ACL injury in the treated groups. The decrease in risk was noted to be 85% for male subjects but only 52% for female subjects. Some of the included trials included both contact and noncontact ACL injuries, which further complicated determining a true risk reduction.
The heterogeneity precluded the authors from determining the best set of activities for ACL injury prevention. However, the successful programs typically focused on neuromuscular training performed for a minimum of ten minutes three times a week.
The scientific quality of many of the included studies was low, and this represented a limitation of the review. The heterogeneity in the design and outcome measures of the included studies was a further limitation but was well handled by the authors of the review. They have demonstrated that these training programs have a definite impact in decreasing the risk of ACL injury. They have demonstrated the need for additional research to determine the most effective exercises to reduce this risk. There is a critical need for additional research in this area to improve the safety of active individuals who are at risk for ACL injuries.