Treatments and Long-Term Effects of Sports-Related ACL Injuries

Author: Emily Agemura


In sports, injuries are inevitable. With the amount of agility, athleticism, and, in some cases, contact involved in sports, it is no wonder why there are so many injuries. One of the most debilitating injuries for competitive athletes are anterior cruciate ligament (ACL) tears. With  approximately 250,000 to 300,000 individuals in the United States tearing their ACL every year, it is one of the most common injuries seen by orthopedic surgeons (Erickson, Pham, & Haro, 2016). Individuals who are in sports such as football, basketball, soccer, gymnastics, tennis, and skiing are at an increased risk of an ACL injury (Gulick, 2020).  Some other risk factors for ACL injuries in sports may include being female, improper shoes, the playing surface, and dry weather conditions (Alentorn-Geli et al., 2014). Being female may be a risk factor because of the differences in the muscles women use compared to men when using their legs. This difference in muscle activation puts different levels of strain on the ACL and contributes to the higher incidences in females (Cleveland Clinic). Having the right shoes on is also important because they typically help provide traction and stability. It was found that some shoes provide greater traction and support than others, so it is important to carefully research which shoes are best for the sport being played, especially when the sport requires them to play on artificial turf (Alentorn-Geli et al., 2014). Playing on artificial turf has been shown to increase incidence of ACL injuries since it is not as forgiving of a surface as natural grass, and it is easier for a player to get their foot stuck in artificial turf compared to natural grass (Hospital for Special Surgery). If they are playing on natural grass, dry weather can cause the ground to be harder and make it more difficult to remove cleats from the ground, leading to more stress on areas such as the knee (Alentorn-Geli et al., 2014). Since most of these risk factors are uncontrollable, we can see why ACL injuries occur so often in sports .

Treatment Methods

As for all injuries, the type of treatment that is best for one individual is not always the best one for a different individual, even if the injuries are identical. Treatment can depend on personal preference, sex, age, current/future physical activity level, type of exercise they wish to return to, etc. The one thing to keep in mind is that sometimes treatment is not 100% effective. This means that not only may some individuals not be able to go back to their sport, but they may also have long term problems in their injured knee.

In the case of an ACL tear, there are a couple options for treatment. These include both nonsurgical options as well as surgical options. Nonsurgical options include bracing and physical therapy. The ACL is crucial for controlling movement and rotation of the knee joint, so when an individual tears their ACL, additional support is needed in order to protect the knee (Johns Hopkins Medicine). Bracing helps provides this additional support and gives the knee external stabilization so it does not move in ways that can make the injury worse. Physical therapy for ACL tears can strengthen the leg muscles that support the knee joint as well as help to regain range of motion in the knee (Stensdotter et al., 2013). Physical therapy is so important because it may be able to reduce long term effects associated with ACL injuries and can help to reduce future injuries to the same area. When someone gets injured, it is commonly due to strength imbalances or weak muscles surrounding the affected area. This is one of the reasons why preventative measures are so important. When an athlete builds muscle associated with key aspects of their sport, those areas are able to resist injuries more effectively. When completing the exercises for the injured knee, it may be a good idea to do them on the opposite knee as well. This can reduce the chances of injuring the other knee. Although nonsurgical options may be the best option for some, ACL reconstructions seem to be the better option for most ACL tears, especially for those who are highly active and are involved in sports that require a lot of agility. It is recommended that if someone does decide to undergo a reconstruction that they make the decision fast. Delaying the surgery may actually be harmful to an individual and increase knee instability or failure of the reconstruction (Erickson et al., 2016). After a reconstruction, it is important for the individual to receive physical therapy. After the surgery, the muscles around the knee need to be strengthened to improve the chances of success of the reconstruction. In addition, it may help to reduce pain and may make patients more comfortable moving their knee. One study found that those who undergo ACL reconstruction may have a fear of movement and/or reinjury, which can then affect the outcomes of rehabilitation. When individuals have this fear of movement/reinjury, it is usually because they are afraid of the pain that also goes along with it (Chmielewski et al., 2008). By being in a more controlled environment where they are surrounded by professionals, they may be less fearful to get injured again and move their knee around more than they would have without physical therapy .

Long-Term Effects

            There are a few long-term effects that someone with a previously injured ACL should be aware of. The most likely consequence is osteoarthritis (Altentorn-Geli, et al., 2014). Osteoarthritis is the most common form of arthritis and happens when cartilage that cushions the ends of bones wears down. It is predicted that the reason why osteoarthritis occurs in so many with ACL injuries is because the initial impact which caused the ACL to tear also disrupts other structures within the knee. This disruption and change in the anatomy of the knee can lead to an increased amount of force on the cartilage and other joint structures (Friel & Chu, 2013). Although it isn’t completely preventable, there are some things an individual can do to lessen the severity. This includes daily exercise and maintaining a healthy body weight. Daily exercise will help the joints from getting too stiff and will also help build the muscles around the joints. Maintaining a healthy body weight will help decrease the stress on the joints, especially since the knees help support most of the body.            

Other effects that an individual should be aware of are reinjury, injury of the opposite knee, and decreased balance of the injured leg. It has been reported that between 1.7% and 29.5% of individuals who receive a reconstruction injure their knee again. Reinjury can be due to multiple factors including age, graft type, activity level, timing of their return to sports, etc. (Erickson et al. 2016). As for injury to the opposite knee, this can be due to the compensation methods an individual uses. When someone injures their knee, they are likely to heavily rely on their opposite leg to perform different activities of daily living, such as walking. This heavy reliance on their opposite leg may increase their risk of injuring it. As for decreased balance, one study found that individuals who injured their ACL more than 20 years ago had issues with balancing on that leg without support. About 39% of the individuals who participated in the study could not balance on their previously injured leg for 30 seconds (Stensdotter et al., 2013). Now that we know there are long term effects on balance and other aspects of the knee, physical therapists may be better able to create rehabilitation plans for those who undergo ACL reconstructions. In addition, this may motivate individuals who have injured their ACL to continue with their physical therapy exercises even after sessions and continue to strengthen the muscles surrounding the knee.


There are a few options for individuals who tear their ACL. This includes bracing, physical therapy, and reconstruction. For athletes involved in high demanding sports, reconstruction is generally recommended. After injury, individuals should be aware of their increased risk for osteoarthritis, the risks of reinjury and injury to their other knee, and the changes in their balance. Building the muscles surrounding the knee and exercising daily is crucial. The only thing those with ACL injuries should be cautious of is doing too much too fast.


Alentorn-Geli, E., Mendiguchía, J., Samuelsson, K., Musahl, V., Karlsson, J., Cugat, R., & Myer, G. D. (2014). Prevention of anterior cruciate ligament injuries in sports. Part I: systematic review of risk factors in male athletes. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 22(1), 3–15.

Chmielewski T.L., Jones D., Day T., Tillman S.M., Lentz T. A., George S. Z. (2008). The Association of Pain and Fear of Movement/Reinjury With Function During Anterior Cruciate Ligament Reconstruction Rehabilitation. Journal of Orthopedic & Sports Physical Therapy, 38(12), 746-753.

Cleveland Clinic. ACL (Anterior Cruciate Ligament) Tears.

Erickson, B. J., Pham, A., Haro, M.S. (2016). Risk of Reinjury or Subsequent Injury After Anterior Cruciate Ligament Reconstruction. Operative Techniques in Sports Medicine, 24(1), 65-72.