Genetically Predisposed to Risk of ACL Rupture In Females

Rupturing the anterior cruciate ligament(acl) is considered to be the most horrific and feared injury in sports. The ACL is a ligament that connect the femur to the tibia and prevents the tibia from sliding in front of the femur. There has been a study that shows how based off of the lack of the  COL5A1 gene, athletes can be predisposed to tearing their acl. The major structural constituents of ligaments are collagens, specifically types I and V. Of late, the gene that encodes for the α1 chain of type I collagen has been shown to be associated with an increased risk of cruciate ligament ruptures. The COL5A1 gene encodes for the α1 chain of type V collagen, and has been shown to be associated with Achilles tendon injuries, which lead to the suspicion that the COL5A1 gene could also be correlated with ACL ruptures. The study had a control group of physically active females with no history of ACL tears and another group of females who all have history of ACL tears. The results showed that the ACL group severely lacked the COL5A1 gene, leading to a correlation between ACL tears and a lack of the COL5A1  gene.

Genetic Differences Found in Female Athletes with ACL Injuries

              Almost everyone knows of someone who has injured their anterior cruciate ligament (ACL), as it is a very common injury in sports. However, people may not know that females are two to eight times more likely to injure their ACL than males. But, why is this true? Is it because of an anatomical or hormonal factor, or is it based on genetics?

 In a study recently performed at the American Academy of Orthopedic Surgeons, a biopsy of ruptured ACL tissue was obtained from seven male and seven female athletes. There were thirty-two differentially expressed genes isolated from the tissue, fourteen of which were not linked to the X or Y chromosome. These fourteen genes were grouped according to skeletal muscular development, function and growth. In females, altered responses in signaling pathways that regulate cartilage and tissue growth were found. Researchers believe that these findings will help determine the role of genetics in ACL structure, and the tendency toward increased injury in female compared to male athletes.

I found this article to be interesting, especially because I work with injured athletes on a daily basis, working at an athletic training room. However, I think more research needs to be done on this topic involving athletes of various ages and cultural backgrounds for the research to be considered substantial. Studies should be performed on much larger quantities of athletes, as well, as opposed to only fourteen being used in this study.

Article: http://www.sciencedaily.com/releases/2014/03/140313092609.htm

Related Article:  http://www.aaos.org/news/aaosnow/nov10/research3.asp

New Ligament in Human Knee

     Recently discovered, scientists have identified a new ligament in found in human knees. Now known as ALL, anterolateral ligament, this band of fibrous tissue now has a name.  This fibrous tissue was always known to be in the knee, but it was never described until recently. When scientists dissected 41 human knees, all but one was found to have this ligament ALL. Running along the front side of the knee, ALL can be the reason why some people who have had ACL surgery in the past still have problems with their knee giving out during activities. 

    Although 40 of the knees in the dissection did have this ALL ligament, it is puzzling that the one person did not.  Perhaps the reason ALL was not present in the one person could be due to the genetic background? Perhaps the real reason why the person did not have the ALL ligament in his or her knee will be uncovered soon.