ACL reconstruction Part 1: One of Australia's biggest burdens... what can we do?
Australia has the highest reported rates of anterior cruciate ligament (ACL) injury in the world. Between 2000 and 2015, over 197,000 primary ACL reconstructions were performed in Australia with the injury costing the hospital system an estimated $142 million a year (this figure doesn't include cost associated with rehabilitation, disease burden, and societal costs).
ACL tears commonly occur in sports that involve turning, twisting and pivoting such as AFL, rugby and netball. The group at greatest risk are men aged 20–24 years, women aged 15–19 years, and the rate of reconstruction is increasing most rapidly among those aged 5-14 years. Not just that, revision ACL (reconstruction of a failed ACL reconstruction) is increasing more rapidly than that of primary ACL reconstructions.
What is the ACL?
The anterior cruciate ligament is one of the 4 main ligaments of the knee and is primarily responsible for preventing the tibia (shin bone) from sliding forward on the femur (thigh bone) at 30-90 degrees of flexion as well as preventing internal rotation of the tibia by providing rotational stability at the knee. In addition to the structural support it provides, the ACL also contains mechanoreceptors that are important in detecting changes in movement, position of the knee joint, and tension, in order to provide adequate stability to the knee, such as when running or jumping.
Why is it such a problem?
One of the major consequences of poor recovery following an ACL tear is ongoing knee instability. This abnormal movement can create extra stress on the ligaments of the knee, meniscus and bone. In general, there is an increase risk of osteoarthritic, disability and tears to the meniscus, that acts a shock absorber within the knee. As a result, there may be increase difficulty in performing simple daily activities, and inability to return to previous physical activities such as sport.
Surgical vs conservative management
Surgical management, which is typically an ACL reconstruction, involves removing the torn ligament and replacing it with a tendon graft, commonly taken from the hamstring or patella tendon. This aims to improve knee stability by replacing the unstable ligament. In the short term, surgery may be a good option for those with sever instability or feels like their knee is "giving way". However, as with most surgeries, there is the possibility of complications such as infection. On top of this, the site of graft may need additional time for recovery.
Conservative (non-surgery) management, usually involves the use of progressive therapeutic exercises aimed at improving the strength and balance of the knee and lower body. This aims to improve the muscle function around the knee, as a substitute for the torn or missing ACL, to provide enough stability. However, if unsuccessful, the ongoing instability may lead to further joint damage. But in saying so, there's currently insufficient evidence to show that surgery can protect against these degenerative changes.
ACL tears are one of the most common injuries affecting the knee, with poor management leading to difficulty performing daily activities and disability. However, the best pathway to manage this injury is still uncertain. In further parts of this blog, we will look further into recovery from ACL reconstructions, and what conservative management may look like and discuss return to sport.
Andrade R, Pereira R, van Cingel R, et al. How should clinicians rehabilitate patients after ACL reconstruction? A systematic review of clinical practice guidelines (CPGs) with a focus on quality appraisal (AGREE II) British Journal of Sports Medicine 2020;54:512-
Baron JE, Parker EA, Duchman KR, Westermann RW. Perioperative and Postoperative Factors Influence Quadriceps Atrophy and Strength After ACL Reconstruction: A Systematic Review. Orthopaedic Journal of Sports Medicine. June 2020. doi:10.1177/2325967120930296
David S. Logerstedt, Lynn Snyder-Mackler, Richard C. Ritter, Michael J. Axe, and Joseph J. Godges. Knee Stability and Movement Coordination Impairments: Knee Ligament Sprain. Journal of Orthopaedic & Sports Physical Therapy201040:4, A1-A37
Monk AP, Davies LJ, Hopewell S, Harris K, Beard DJ, Price AJ. Surgical versus conservative interventions for treating anterior cruciate ligament injuries. Cochrane Database of Systematic Reviews 2016, Issue 4. Art. No.: CD011166. DOI: 10.1002/14651858.CD011166.pub2.
Zbrojkiewicz, D., Vertullo, C. and Grayson, J.E. (2018), Increasing rates of anterior cruciate ligament reconstruction in young Australians, 2000–2015. Medical Journal of Australia, 208: 354-358. doi:10.5694/mja17.00974