Hormone

Risk of Knee Ligament Injury Tied to Ovulation

I thought this article was interesting in that it related hormonal fluctuations with risk of ligamentous injuries. The idea that hormones change ligaments is by no means new–relaxin is secreted during pregnancy to allow the pubic symphysis to stretch and allow passage of the newborn through the birth canal. This article, however, suggests that other hormones may have similar characteristics. Consider this…hormones are readily modified by environment. It would be not great stretch to consider environmental impacts on hormonal regulation and subsequent alterations in ligament strength and flexibility. Might this lead to increased aches and pains seen in some chronic diseases such as fibromyalgia and rheumatoid arthritis?

Meeting of the American Orthopaedic Society for Sports Medicine Ovulation, and possibly oral contraceptive use, may play important roles in women’s risk of anterior cruciate ligament (ACL) injury, according to study findings presented at a recent meeting of the American Orthopaedic Society for Sports Medicine in Keystone, Colorado. Principal investigator Dr. Edward M. Wojtys of the University of Michigan in Ann Arbor and colleagues evaluated 65 women with ACL injuries and collected urine samples within a day of each woman’s injury to establish the phase of her menstrual cycle. They found that more than 2.5 times the expected number of injuries occurred during ovulation than during other points of the menstrual cycle. Because this pattern emerged only among women who were not on birth control pills, the findings also suggest that oral contraceptive use may provide some measure of protection from the injury, the researchers note. However, lead study author Dr. Wojtys stressed that the findings do not suggest birth control pills offer a way to prevent ACL injuries. “This research does not justify pulling young ladies out of sports or putting young women on oral contraceptives in order to prevent ligament injuries,” Dr. Wojtys, the director of sports medicine at the University of Michigan, said in a statement. “There is some evidence that ACL injuries are tied to the menstrual cycle and probably to hormones,” he added, “but we don’t have enough information yet to justify the use of oral contraceptives in order to prevent ligament injuries.” Studies indicate that female athletes rupture their ACLs up to eight times more often than male athletes do. A number of factors — from differences in musculature and training methods to women’s wider hips — are believed to account for the higher rate of ACL injuries among females. Previous research has also pointed to the role of the menstrual cycle, showing that ACL injuries are more common during ovulation. Estrogen levels are increased during ovulation and some researchers have speculated that hormone fluctuations factor into women’s ACL injury risk. But Dr. Wojtys said this relationship remains unproven. “Even if it is the menstrual cycle that is having some effect on the susceptibility of soft tissue…the susceptibility is not clear,” he said in the statement. “People are jumping to the conclusion that it is estrogen and it is acting at the anterior cruciate ligament, when in fact, there are multiple places where any hormone could act, including muscles, the central nervous system and the peripheral nervous system,” Dr. Wojtys added. He suggests further research is needed on how hormones affect ligaments and other soft tissue, as well as how hormones might alter the function of muscles and nerves.