The following two papers show the gradually increasing genetic knowledge base in ACL science, and medicine generally.
The first paper is illustrative of the impressive work being done showing that not all connective tissue is created equal. At the extremes, such as Ehlers Danlos syndrome, this has always been appreciated. But scientists are now able to correlate genetically different collagen with differing injury rates. In this study, different haplotypes of the COL5A1 gene were associated with greater or lesser risk of ACL tears. A study group and control group of soccer players was used. As the authors state, this a non-modifiable risk factor physically. However, one might, for example, counsel an athlete with a high risk haplotype to undertake an ACL prevention program given the greater risk.
The second paper points out different genetic makeups in different athlete populations. INDEL markers were used to identify the ancestry of the athletes as of European, African or AmerIndian ancestries. It was found that the European athletes had a higher rate of ACL tear than the other groups. This represents only a first step toward the ultimate goal of finding what the genetic variant in the population group is that produces the predisposition. As with the prior paper, the genetic makeup is obviously a non-modifiable risk factor. Nonetheless this expanding knowledge base may cause some to modify behavior regarding ACL risk prevention, sport selection or treatment in the future. This kind of potentially usable knowledge is many years away, but is an interesting new area of study. As with most new areas, useful applications of the knowledge would be expected to become more apparent as the knowledge gained becomes greater.
Chadwick Prodromos, MD is Medical Director, Illinois Orthoapedics and Sports Medicine Centers and Associate Professor of Orthopaedic Surgery at Rush University College of Medicine in Chicago. He is the author of The Anterior Cruciate Ligament, 2nd Edition. Click here to download a free chapter.