Influence of Menstrual Cycle on Anterior Cruciate Ligament Injuries in the Knee: A Systematic Review of the Literature

Anterior cruciate ligament injuries of the knee represent an increasing problem among the active female population in comparison to their male counterparts. Besides temporary or prolonged joint dysfunction, such injuries may predispose an individual to early osteo-arthritis. Recognizing the sex differences is essential for the determination of preventive measures against these injuries. Besides anatomical and biomechanical differences, the role of hormonal oscillation during the menstrual cycle has been hypothesized. This manuscript presents a literature review based on cruciate ligament and menstrual cycle research published between 1992 and 2012. According to the experimental and epidemiologic studies, menstrual cycle was shown to be linked to anterior cruciate ligament injuries. The pre-ovulatory phase represents an increased risk, with the peak serum levels of estrogen emerging toward the end of that phase. However, the significance of menstrual cycle seems to be of lesser importance in preventive measures against female anterior cruciate injuries.