ACL Injuries in Female Athletes

There has been a steady increase in the number of professional female athletes. The success of the Lionesses and their huge following, with a growth in television covered of all female sports, has led to an increase in the number of females ( normally young) playing sport. Unfortunately, with this increased participation comes an increasing number of injuries sustained.

Studies have shown a difference in sports related injuries between sexes, with females sustaining higher rates of non-contact injuries.

Pivoting sports such as football, netball and hockey have a particularly high risk of ACL rupture, with female athletes having a 3-6 times higher rate of ACL rupture compared to their male counterparts. Half of all female ACL reconstructions undertaken are due to football.

Keira Walsh came off during the 1-0 win over Denmark in this world cup, fearing an ACL injury. England play this world cup without Leah Williamson and Beth Mead , both with confirmed ACL ruptures. Arsenal have had 4 ACL ruptures in 6 months.

ACL injuries not only prevent the athlete playing, with potential loss of income and psychological problems, but can have long-term consequences including further knee injuries and arthritis. Following ACL reconstruction many athletes do not return to their pre injury level of sport, with many not returning at all.

It is important to try to prevent injury rather than deal with its consequences.

There are a number of ACL injury prevention programmes (prehabilitation) including the FIFA 11+ injury. Web searchers using “ACL Prevention Programme for females” shows a large number of other programs with accompanying YouTube videos.

Power Up To Play is an initiative set up by medical professionals to improve the training of coaches and thereby reduce the number of injuries.

Female athletes are exposed to hormones, their own (endogenous), and external (exogenous) normally used for contraception or control of bleeding. During the menstrual cycle the levels of the hormones Oestrogen, Progesterone and Relaxin cyclically vary, to prepare the lining of the womb for a fertilized egg, triggering ovulation and then cause shedding of the endometrium (menstration) if fertilization has not occurred.

Oestrogen reduces the proliferation of collagen increasing the risk of ACL rupture in the early stages of the menstrual cycle. After ovulation Ostrogen levels fall and progesterone levels rise which is ACL protective. The female ACL has Relaxin receptors ( unlike males), this hormone induces collagen breakdown and causes laxity in ligaments, increasing the risk of rupture at days 21-24 of the cycle.

Some studies have shown that the use of the oral contraceptive pill may be protective against ACL rupture, but the evidence is low and should not be looked on as a recommendation.

As well as hormonal influences, there are other biomechanical differences leading to an increased risk of ACL injury. Females are slightly more knocked-kneed, (due to a wider pelvis) with a higher posterior slope on the top of the tibia (shin bone). The inter-condylar notch (gap at the end of the thigh bone) in which the ACL sits is narrower in females.

Women wear sports shoes designed for men. They often play on poorer quality pitches. Poorer quality coaching and training may have an influence. Girls do not enter elite player develop programmes as young as boys.

Other injuries are more common in female than men athletes include ankle sprains, bone stress injuries and anterior knee pain. There are many causes for this including nutritional, bio-mechanical and hormonal influences.

It is important that the number of ACL are reduced as much as possible. This involves educating athletes’, coaches and parents. Appropriate prehabilitation and training, the use of correct equipment and ensure correct nutritional input are all important.

If an injury does occur , it is important that is treated correctly in a timely manner. Unfortunately, ACL ruptures are still frequently missed in casualty departments.

Most ACL injuries occur during non-contact situations. Classically the athlete twists or cuts on the knee. There is a pop, they collapse to the ground, cannot play on and have to be helped off. The knee usually swells almost immediately. This injury is not seen on an x-ray. The knee may improve but can feel unstable and usually gives way on return to sport.

Early consultation with a knee surgeon ( who has an interest in ACL’s) is recommended to decide on the best course of action.