Introduction
Cruciate ligaments are arranged like the letter X hence they are also called cruciform ligaments. The ligaments are primarily found on the knee and function in not only stabilizing the joint but also in allowing a wide range of motion. In the knee, the anterior cruciate ligament (ACL) and the posterior cruciate ligaments (PCL) criss-cross to form the cruciate ligament. The two ligaments are strong round bands that extend from head of the tibia to the intercondyloid notch of the femur (Margheritini, 2011). The anterior cruciate ligament lies lateral and crosses the medial posterior cruciate ligament like the limbs of an X. The two ligaments are named according to their insertion to the tibia.
The Cruciate ligament originates from the medial and anterior aspect of the tibial plateau and runs superiorly, lateral and posteriorly towards its insertion to the lateral femoral condyle. The ACL is made of posterolateral and anteromedial bundles which provide a strong straining force of anterior translation (Siegel, 2012). The ligament also helps prevent excessive medial and lateral rotation. In addition, it also prevents excessive varus and valgus stress (Wu, 2015).In addition; the ligament may also take part in checking expansion and hyperextension of the knee joint. Similarly, PCL originates from the posterior intercondylar area and runs anterosuperiorly to insert into the lateral surface of the medial femoral condyle (Canale, 2013). The PLC acts to resist anterior translation of femur on the tibia (Crespo, 2015). Acting together with ACL, PCL acts in guiding the instantaneous centre of rotation of the knee hence controls the kinematics of the knee joint.
ACL injury is one of the serious sports injuries leading to surgery related hospital admissions especially among young adults playing multidirectional sports (Janssen,2012).Such injuries consequently cost the injured athlete high treatment cost, losing time from the sport and even increasing the risk of early osteoarthritis.
Incidence of ACL Injuries in Australia
According to the Scandinavian journal of medicine and science in sports, a study done in Australia over a 5-year study period, there were 50187 ACL reconstructions between 2003 and 2008 (Janssen, 2012).This value is split into 39866 reconstructions making about 79.4% in the private sector and about 10321(20.6%) in the public sector (Janssen, 2012).The survey also revealed that the number of reconstructions increased in males, females, public hospitals, private hospitals and nearly all age groups. The study showed a linear increase in the annual incidence of ACL injuries in both males and females in particular age groups: a 5-14 year with a P-value of 0.005, 35-44 years at P=0.04 and 45-54 years at p=0.04 for males (Janssen, 2012). Females 15-24 years had a P-value of 0.02, 25-34 years P=0.03 and those 45-54 years P=0.04 (Janssen, 2012).
Moreover, according to the study, population-based incidence of reconstructions of ACL per 100,000 was 52.0 and increased by about 14% over the 5 year period of study in both males and females (Janssen, 2012). According to these data, the incidence of ACL reconstruction rose rapidly through adolescent ages and early childhood before gradually declining. The data also revealed a higher incidence of ACL injuries compared to females in all age groups less than 75 years as shown in figure 1 (Janssen, 2012). Moreover, in certain age groups such as 15-24 and 25-34 years, the incidence of male injury was twice as much as that of the females as shown in figure 1 below.
Out of the 50187 cases of ACL injuries recorded during the study period, in 9425 of the cases, the activity when the victims were injured was specifically recorded (Janssen, 2012). Out of the 9425 cases, 6824 was sports related making about 72% of the specified cases (Janssen, 2012). Another 2155 of the cases out of the 50187 were exercise related but could not be associated with any sport (Janssen, 2012). The remaining 39,673 of the cases, making about 79% of the total, the activity was not indicated and could not be linked to any exercise (Janssen, 2012). The study approximated the “true” ACL injuries related to sports to be about 36,337 by allocating the 39673 unknown cases proportionally with respect to the known cases (Janssen, 2012). This made about 72% of the reported cases, contributed predominantly by soccer, Australian Rules football and netball (Janssen, 2012). Moreover, both alpine and downhill skiing reported the highest ACL reconstruction incidence per 100,000 participants annually as indicated in figure 2.
Figure 1
Source: Janssen, K. W., et al. (2012)
Figure 2 Table showing annual ACL reconstructions per sport in Australia
Source: Janssen, K. W., et al. (2012)
Government Expenditure on ACL Reconstruction in Australia
Approximately $75 million was spent annually on hospital and surgery costs associated with ACL reconstructions over the 5 year study period (Janssen, 2012). These costs however only involved direct admissions and treatment in the hospital. There are additional costs related to the treatment of ACL injury which cannot be measured currently with the available data such as post-operative rehabilitation and loss of income due to being away from employment. The figure would rise to $100 million per annum if costs such as those of non-surgical cases and some indirect costs were included (Janssen, 2012).
Incidence of ACL Injuries in Australia Compared with other Countries
The incidence of ACL reconstructions in Australia at 52.0 per 100,000 is considerably higher than other previously published incidences such as New Zealand at 37.8, United states at 30-33, Sweden 32, Norway at 34 and Denmark at 38 (Janssen, 2012).In Australia, the incidence for men was found be highest at 163-181 reconstructions per 100,000 person years for ages 15-34 years (Janssen, 2012). This was higher compared to New Zealand at 150-160 ACL reconstructions per 100,000 for men 20-29 years of age (Janssen, 2012). For women, however, the incidence of ACL reconstructions in Australia was at 62-72 reconstructions per 100,000 person-years, lower than that of New Zealand at 70-80 reconstructions per 100,000 person-years (Janssen, 2012). This was however still substantially higher than the incidence in the United States at 40 ACL reconstructions per 100,000 (Janssen, 2012).
The age group 15-34 for both men and women in Australia posted the highest ACL injury incidences at 120 ACL reconstructions per 100,000 person-years (Janssen, 2012). This was also higher than the incidence from the Norwegian national knee ligament registry at 85 per 100,000 person-years for the age group 16-39 which was at the highest risk (Janssen, 2012). However, not all injuries involving ACL are diagnosed and similarly not all ACL injuries which are diagnosed are operated on. This means that not all ACL injuries are treated at the hospital and hence the number of ACL injuries treated conversely in Australia is not known. We can infer that due to the higher annual ACL reconstructions in males than females in Australia, New Zealand, and the United States, there are biases in sports participation. This could probably mean that males play sports that put them at higher risks of ACL injuries than females, such as the various football codes.
Even though exercising is important in the maintenance of good health, those who exercise by participating in sports from a very young age can suffer injuries that may curtail their ability to exercise throughout their life. This consequently hinders their ability to stay healthy and avoid diseases such as diabetes, obesity, and cardiac disorders. Scandinavian ACL registries dated 2004-2007 show that a total of 17 632 injuries occurred with most occurring at 25 years of age (Wojtys, 2010). According to the registry, the skeletally immature individuals sustain rising number of injuries related to ACL. According to the study, even though the risk for ACL injury is generally low in individuals with open growth plates, the risk is certainly increased by participating in sports.
ACL Injury Prevention Strategies
Implementation of risk factor surveillance and prevention strategies for injuries related to ACL requires proper understanding of the mechanisms underlying failure of the ligament. Sport related ACL injury is rampant in adolescents probably because of the poor common landing and pivot maneuvers. Even though physical contact may play some role in ACL injury, most injuries, especially among women, seem to be non-contact in nature shown by the 70% of the ACL injuries occurring in the absence of contact in most elite females (Wojtys, 2010). To prevent ACL injury among sports individuals, it is important that the sportsmen and women be made aware of prevention tips and various relieving exercises. It is important to make the athletes aware of the importance of always warming up before playing to improve blood circulation in their muscles and joints.
The sportsmen and women should also be aware of the importance of stretching before playing. Flexibility on the thighs, hips, and especially tight areas may help maintain the ideal form. Most importantly, it is important that the sportsmen and women are aware of the risks involved in the particular type of sport they are playing.
Conclusion
In conclusion, further research is very critical to examine the prevailing high incidence of ACL reconstruction surgery in Australia compared to the western countries. Injuries related to ACL play a huge in contributing to the burden of injury and health care costs in Australia. Cruciate ligament injury is a critical issue that can not only alter one’s stability but also lead to disability in walking. Awareness of the risks and how to curb them can, however, help sportsmen and women prevent any injuries involving the cruciate ligaments.
References
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Crespo, Bernardo, et al. "Injuries to posterolateral corner of the knee: a comprehensive review from anatomy to surgical treatment." Revista Brasileira de Ortopedia (English Edition) 50.4 (2015): 363-370.Anatomy and biomechanics, para.4
Janssen, K. W., et al. "High incidence and costs for anterior cruciate ligament reconstructions performed in Australia from 2003–2004 to 2007–2008: time for an anterior cruciate ligament register by Scandinavian model?" Scandinavian journal of medicine & science in sports 22.4 (2012): 495-501.pages.1-6
Margheritini, F., & Rossi, R. (2011). Orthopedic sports medicine: Principles and practice. Milan: Springer.page.302
Siegel, Leon, Carol Vandenakker-Albanese, and David Siegel. "Anterior cruciate ligament injuries: anatomy, physiology, biomechanics, and management." Clinical Journal of Sport Medicine 22.4 (2012): 349-355.main results, para.1
Wojtys, Edward M., and Ashley M. Brower. "Anterior cruciate ligament injuries in the prepubescent and adolescent athlete: clinical and research considerations." Journal of athletic training 45.5 (2010): pages, 509-512.
Wu, Y. (2015). Knee joint vibroarthrographic signal processing and analysis.page.2
