Are ACL Tears Genetic?
BY LAUREN UZDIENSKI, SEPTEMBER 29, 2010
The New York Times reports this morning on a hereditary predisposition to ACL tears. A study published in the British Journal of Sports Medicine noted several risk factors for ACL tears that were common between twins, furthering data from a year earlier that identified specific genetic markers that correlated to knee injuries.
A fraternal female twin study at the Cincinnati Children's Hospital Medical Center showed a number of common anatomic factors between patients who eventually experienced ACL tears, including increased knee abduction angles, decreased knee flexion angles, increased general joint laxity, decreased hamstring/quadriceps ratios and narrow femoral intercondylar notches. Researchers in South Africa have also explored specific genes correlated with ACL tears, including the COL1A1 and COL5A1 markers, both of which code for collagen. The COL5A1 study pertains specifically to women, with the researchers concluding, "This is the first study to show that there is a specific genetic risk factor associated with risk of anterior cruciate ligament ruptures in female athletes." Interestingly, while more men rupture their ACLs on an absolute basis than women, a scan of the literature shows that many of the genetic associations with ACL tears have been identified with female cohorts.
With ACL ruptures on the rise, schools and individual athletes have focused on preventing these injuries with exercise and warm-up programs. Family history offers one way to identify susceptible athletes, and genetic screening may eventually provide more insight into injury risk.
