ACL knee injuries; is this a predictor of a similar injury later in life and if so, why?
The ACL is the large ligament in the knee we read about that happens when someone plants their foot and then twists. Typically, the person hears a pop inside the knee and then feels an instability afterward when they take their next step. The anterior and posterior cruciate ligaments are essential to knee stability, especially when performing side to side and rotational movements of the body. A torn anterior cruciate will make the knee unstable and can predispose you to other knee joint injuries unless it is surgically repaired which restores stability.
ACL injuries are most common in adolescent girls, since their bodies change during puberty. Their hips are likely becoming wider, which increases the angle at the knee affecting the stability of the knee. Unlike male adolescents, a female with foot overpronation (the foot falls in and turns out with each step) is mechanically more at risk since the wider hips will likely cause the foot to turn out and the knee to roll in. Risk is further increased with body asymmetries, when one side works one way due to the shape of the feet and leg and the other side works differently. This asymmetry typically results in a distorted or torqued core, which is likely not noticed by athletic trainers, pediatricians and other medical or screening professional. A torqued core will place more of the strain into the hips, and the legs will tighten, increasing the likelihood of an ACL injury when the foot plants and the body rotates.
A number of years ago, a group of ATC’s (certified athletic trainers) developed a series of core stability exercises for adolescent girls to do prior to athletic activity and they found that the exercises resulted in fewer ACL injuries.
Another phenomenon that has been recently studied is that those who had an initial ACL injury are more likely to experience a second injury. While the recent study only looked at the injuries, it is likely that the ACL injury was the symptom and that the mechanical aberration that created the injury (the actual problem) was never corrected, creating the same conditions that allowed the first ACL injury to occur.
The pelvis is designed to absorb shock throughout the kinetic chain (series of joints from the ankle to the knee and hip). If the pelvis is distorted, it will not absorb shock or transfer forces throughout the body properly, resulting in a loss of flexibility around the ankle and hip. These condition will set the stage for the next injury to the hip, knee, ankle of foot. A tight hip, tight ankle and a loss of shock absorption in these areas will place more force through the knee than it is capable of absorbing. The person plants and rotates and the ligament tears, causing what we know as the ACL injury which will usually damage the meniscus as well.
Many ACL injuries are preventable if we screen the patient while they are young. While it is common to screen adolescents for scoliosis, another minute can provide information about their feet, asymmetry and body style that we can use to help them avoid injury which would include exercises, the use of off the shelf foot orthotics and advice on proper footwear. Some students can definitely benefit from a few visits to the chiropractor as well.
Young People At Risk of Second Injury After Knee Surgery
Study finds repeat problems common after early ACL repair
SATURDAY, March 28, 2015 (HealthDay News) — One-third of young athletes who have surgery to repair the anterior cruciate ligament (ACL) in the knee suffer another ACL injury later in life, new research finds.
“Our study shows that young knees are more prone to re-injury than the adult population when compared to other research in this area, and is the first study to examine the incidence and risk factors for further ACL injury in a solely juvenile population over the long term,” study author Dr. Justin Roe, of the North Sydney Orthopaedic and Sports Medicine Centre in Australia, said in a society news release.
“While surgery still may be the best option for many ACL injuries, it brings to light the important factors physicians must consider when treating the younger population,” he added.