Each year in the U.S., more than 200,000 cases of ACL injuries happen to both recreation and competitive athletes who play agile sports, such as soccer, skiing, basketball, and baseball. About half of the cases require knee reconstruction, according to the Department of Orthopaedic Surgery at the University of California San Francisco. About 70 percent of these injuries are caused by non-contact reasons, while the remaining 30 percent are caused by direct contact of the knee. Even though ACL reconstruction (ACLR) has a 90 percent success rate, there are patients who still opt out to do surgery, who may have a higher chance of re-injuring or suffering from osteoarthritis in the knee than those who choose ACLR. However, surgeons and physical therapists should not just focus on the anatomy and exercise. Dr. Howard Lusk, M.D., who is the Chief of Sports Medicine and Arthroscopy at Westchester Medical Center in Valhalla, New York, strongly encourage medical professionals and coaches to address the psychological factors of the patients, which are just as important as the physical aspects of knee ACL injuries.
“Sometimes the athlete’s physical issues are addressed, but they were not prepared emotionally and psychologically for a return to sports, and in the end you have an athlete ill-suited for a return to their chosen sport,” Lusk wrote on his blog. He stated that most people think that athletes who had ACLR and recovered from ACL injuries are able to return to playing their sport at the level where they left off. However, a 2014 study published in the American Journal of Sports Medicine showed evidence that this belief is not necessarily true for most athletes.
Dr. Sharon Hame, M.D., from the Department of Orthopaedic Surgery of David Geffen School of Medicine at the University of California Los Angeles collected data among NCAA Division I athletes in the U.S. who participated collegiate sports from fall 2003 to spring 2008. The study examined the impact of how prior knee surgery, ACL injuries, and subsequent knee injuries and surgeries affected those athletes who returned to play their sport. Among the 456 athletes who completed their evaluation, Hame found that those who had knee surgery or ACL surgery were almost seven or 20 fold more likely, respectively, to re-injury their knee or ACL and about 14 and 893 fold more likely to undergo knee or ACL surgery than the control group who suffered no knee or ACL injuries.
This data raises vital questions to medical professionals and coaches: Are these previously injured athletes ready to play again? Physical therapist and ACL injury expert Trent Nessler, D.P.T., who was a guest blogger on Dr. Lusk’s website, asked whether there are other factors that can influence the risk of re-injury outside of anatomical and biomechanical factors. If athlete A and B had the same success in ACLR and physical rehabilitation, what makes them different in their ability to return to playing their sport? He also added that athletes who suffer from ACL injuries or knee injuries tend to have a fear of re-injury, experience more depression, and even have higher academic test failure and lower GPA, according to data from NCAA and the National Athletic Trainer Association (NATA).
A 2013 study published in the American Journal of Sports Medicine examined whether other factors, such as psychology, could explain why some athletes could not return to their pre-injury level after a successful ACLR. The researchers measured the athletes’ psychological factors before the operation, at four months post-op, and 12 months post-op. Among 187 athletes in the study, almost one-third — 56 athletes — were able to return to their pre-injury sports participation level by 12 months after ACLR. The study stated that the most significant psychological factors that influenced the inability to return to pre-injury levels were psychological readiness, physical recovery expectations, sport locus control (the sense of recovery outcome from external and internal factors), and fear of re-injury. This innovating study provides strong evidence that suggests the athletes’ mindset and behavior could determine whether they can finish their collegiate athletic career or become an orthopedic patient — again.
Still, physical therapists, surgeons, and coaches must not ignore the physical aspects of knee ACL injuries, which are just as important as psychological factors. In a study published in the February 2014 issue of British Journal of Sports Medicine, researchers Benjamin Goerger, Ph.D. and colleagues from Georgia State University found that athletes who had ACL injuries or ACLR developed new movement patterns, such as in landing on the ground from an elevation, which is later immediately followed by a vertical jump. Both groups had increased lateral movement in the knees and hips, which could increase torsional stress in the knees. There was also decreased knee extension during the jump and hip flexion during the landing. These factors, according to the researchers, could increase the likelihood of re-injury.
However, some physical therapists do not entirely agree with this study’s conclusion. “The number one reason for re-injury following ACL surgery is the failure to complete the rehab program,” said physical therapist Michael Haley on an online interview, who practices at Prehab Sports Medicine in Warwick, Rhode Island. “This study takes so few variables in to play, like the type of rehab surgical procedure.” ACL surgery is more likely a correlation to future injury reoccurrence, not necessarily the cause.
“As we know the pain associated with surgery or injury can have effects on the biomechanics,” Haley explained. “These effects can cause the changes noted. Even after the patient is pain-free, they may have made adaptations in the recovery process while dealing with the trauma and post-op stuff that may linger. When we look at the MRI of people who have chronic pain issues, we will see up to 400 other places around the brain light up, places that are not normally associated with the areas that we should see pain for the affected area represented. So even after the injury is resolved, the brain may be sending out protective messages to prevent the knee from re-injuring. These messages may be false and may be the cause of the faulty movement patterns. Personally I believe that we need to place the knee in many differing positions to allow the knee to be able to come out of risky positions. In effect, they have been at risk before and know how to get out of it without injury.”
Understanding and addressing both physical and psychological factors that contribute to knee ACL injuries can establish a greater trust between the clinician and the patient, which is just as important as the healing process. With evolving research in pain science in relation to movement and recovery, the rate of injury and re-injury among collegiate athletes may drop down soon, allowing these superstars to spend more time playing and doing they enjoy rather than spending inside a hospital.
By Nick Ng
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Interview with Michael Haley, PT
University of California San Francisco
Howard Lusk, MD
British Journal of Sports Medicine
The American Journal of Sports Medicine
The American Journal of Sports Medicine