Factors and Mechanism of High Incidence of Anterior Cruciate Ligament Injury in Women

Abstract

Anterior cruciate ligament (ACL) injury is a common serious knee injury in sports medicine, prevalent in high-intensity sports involving sudden stops, direction shifts and jumping. Epidemiological data indicate female ACL injury incidence is 2–8 times higher than males, alongside poorer rates of return to competitive sport post-injury. This gender disparity is a core research topic in sports injury prevention, with existing studies examining anatomical, molecular physiological and biomechanical contributors. Distinct female osseous knee traits including elevated tibial posterior slope and narrower femoral intercondylar notches raise ligament mechanical loading and injury vulnerability. Cyclic estrogen secretion disrupts ligament tissue remodeling and mechanical stiffness. Transcriptomic testing reveals sex-dependent extracellular matrix homeostasis regulation: ACAN, FMOD are upregulated while WISP2 is suppressed in female ACL tissue.During landing and cutting motions, females present abnormal lower-limb kinematics that trigger excessive knee valgus, elevated abduction torque, flexor-extensor muscle activation imbalance and reduced knee dynamic stability. Hormone swings during ovulation impair lower-limb neuromuscular control, creating a high ACL injury-risk window. Though individual risk factors are documented, their synergistic interactions and unified gender-specific injury mechanisms remain unclear, with no gender-tailored standardized clinical intervention frameworks. This review synthesizes multi-factor ACL injury mechanisms in females, summarizes current evidence gaps, and informs future research on gender-linked knee injuries.