Second ACL Injury Risks

By: Dr. Laura Wenger, PT, OCS

Back when I was doing my Doctorate training at the University of Utah, I performed an extensive review of risk factors for repeat injuries or injuries on the opposite side after having an ACL-reconstruction surgery for my final doctorate project. Since then, researchers have continued seeking for answers to the question of why people who have had an ACL injury and surgery have a risk of re-injuring the same knee or injuring the opposite knee, which occurs in anywhere from 3 to 37% of people depending on their activity level, type of sport, and other factors such as age.(1)

In an attempt to reduce the risk of further injury, especially with people who are returning to sports that might put their ACL at risk (such as soccer, football, and any other running/cutting sports), researchers and clinicians have created many “Return to Sport” tests to try to prepare their patients to getting back to their usual activities as safely as possible. These tests are typically looking to see how symmetrical the legs of the patient are with comparing the surgical side with the non-surgical side, as well as with trying to gauge how confident the patient is during the tests as there is more and more information coming out about how confidence in movement can affect quality of movement and, potentially, their risk of further injury. A recent systematic review, which is a grouped analysis of multiple studies, sought to find out whether passing these return to sport tests are associated with actual decreases in the chance of a second ACL injury.(1)

Within the four studies that the researchers were able to look at in this review, approximately 42% of the patients were able to pass the return to sport testing performed.(1) Of those patients that passed their tests, 14% of them went on to have either a re-injury of the originally injuried knee or a new injury of the opposite knee.(1) Unfortunately, the researchers found that experiencing a “passing” grade of the return to sports tests only led to a 3% reduction in risk of injury- which is not a significant amount.(1) The results of this study show that there is still much work to be done in terms of trying to better identify what might place someone at a higher risk of a second ACL injury as well as trying to create tests that are more sensitive so that we can more confidently send patients back to their sport and activities of choice with reduced risk of a further injury. Here at Tomsic PT, we create a very individualized program for each patient to work toward the goal of getting them back to their activities as strong and safe as possible. If you have experienced an ACL injury, either just recently or further in the past, don’t hesitate to see one of our physical therapists for further evaluation on how to best decrease your risk of a second ACL injury.

Brad, Ellen’s husband, skiing some deep and steep snow in Canada this January! Skiing is a sport many folks like to return to after ACL injuries.

1. Losciale JM, Zdeb RM, et al. The Association Between Passing Return-to-Sport Criteria and Second Anterior Cruciate Ligament Injury Risk: A Systematic Review with Meta-Analysis. J Orthop Sports Phys Ther. 2019;49(2):43-54.