ACL Tear
What is ACL tear?
- The ACL (Anterior Cruciate Ligament) is one of the two cruciate ligaments of the knee that helps to stabilise the knee joint. The anterior cruciate ligament (ACL) is the most commonly injured in the knee.
- ACL tears or ruptures are usually sports-related injuries, but can also occur from participation in intense sports, motor vehicle crashes, falls, and work-related injuries.
- Chronic ACL injury can lead to a risk of developing further damage to the knee, leading to cartilage damage and complex, irreparable meniscus tears.
How is Australia impacted by ACL tears?
- As a sporting nation, Australia has a high rate of ACL injuries, and women are significantly more affected by ACL tears than men, including the Matildas recent ACL injuries of Amy Sayer, Sam Kerr and Holly McNamara.
- “The risk of ACL tears in women is significantly higher than in men, in fact up to eight times higher,” says Dr Markham.
- “There are several reasons for this. Firstly, women have less muscle mass around their knees than their male counterparts.
“Secondly, women have less testosterone, a key hormone for muscle density.
“And thirdly the female pelvis is wider which puts more stress on the soft tissues of the knee, anatomically speaking.”
Fluctuating oestrogen in the menstrual cycle can also impact elasticity of the tendons and ligaments which can make them more prone to injury.
Some studies show that the menstrual cycle also makes injury more likely on days 9-14 pre-ovulation. - Increasingly many female Aussie elite athletes are now involved in knee prevention injury programs to target these issues.
- See Netball Australia’s ACL Knee Program here – which discusses how ACL tears represent 25% of all serious injuries, and how to prevent them.
- Despite the fact that ACL tears are more prominent in women, they can be career devastating for men too, and a 2021 scientific analysis of the Newcastle Knights found that ACL ruptures were by far the commonest injury that resulted in the longest time away from sport for league players.
What causes an ACL tear?
- The most common cause of ACL injury occurs during sports and fitness activities that put sudden pressure on the knee. For example, when changing directions quickly, stopping suddenly, or landing from a jump.
- ACL tears or ruptures can also occur during intense sports, motor vehicle crashes, falls and work-related injuries.
What are symptoms of ACL tear?
- Sudden “thump or clunk” sound in knee joint
- Deep knee pain
- Immediate swelling (due to accumulation of blood in the joint)
- Weakness in the knee
- Difficulty in walking
- Decreased range of motion of the knee
How is an ACL tear diagnosed?
An ACL injury can be diagnosed clinically by physical examination (and history), but the diagnosis is usually confirmed using magnetic resonance imaging (MRI) or X-rays.
How does menopause impact the female knee?
- Female hormones can play havoc with knee pain.
- Women are at much greater risk of ACL tears in their younger years, especially elite athletes.
- Osteoarthritis increases significantly after menopause, and women may notice knee and other joint pain appears or worsens during this time.
- Oestrogen levels drop during menopause, which may contribute to changes in the body that accelerates the osteoarthritis process. “Osteoarthritis is a very common chronic condition in middle to older age adults,” said Dr Markham. “Cartilage is just like a pin cushion pad, or a shock absorber. Arthritis is not just about bone, it’s also the cartilage in between the bones that are getting a little bit worn down.” He says high performance sport is associated with an increased risk of sport-related injury and there is emerging evidence suggesting retired elite athletes have high rates of post-traumatic osteoarthritis.
What are the treatment options for an ACL tear?
- ACL treatment can entail either surgical or non-surgical treatment modalities.
- Treatment for ACL tears is determined by several factors, including the patient’s age, physical demands, activity level, sports participation, and damage to other supportive and stabilizing knee structures.
- Acute treatment consists of “RICE” therapy (rest, ice, compression of the affected knee and elevation of the affected lower extremity).
- The patient should be non-weight-bearing and may use crutches or a wheelchair if necessary. Over-the-counter medications (e.g., NSAIDs) may provide pain relief
- Non-surgical treatments are usually administered through physiotherapy and lifestyle changes.
- The main option for surgical treatment is to repair or reconstruct the torn ACL to restore the internal structure of the knee and maximize stability.
What is the success rate of ACL surgery?
- ACL reconstructive surgery has a high success rate of 80 to 90%.
- Still, some patients may have difficulty deciding whether to have surgery because of the complications it can cause, such as knee stiffness, graft stretching/ re-rupture, infection, tendon sheath cyst formation and blood clots and graft re-rupture.
What factors increase the risk of ACL tear?
- Being female. Multiple factors due to anatomy, muscle strength and hormonal influences, put females at a higher risk for ACL injuries
- Inadequate exercise and warm-up
- The wrong type of exercise
- Inappropriate shoes for exercise
How can I prevent an ACL tear?
- Strengthen the muscles around the knees and core muscles
- Pay attention to jumping, pivoting and changing direction correctly during exercise
- Keep your knees bent and avoid straight-legged landings to ensure proper landing technique
- Wear shoes that provide adequate support and traction for your sport or activity.
- Avoid overtraining
- Watch for any signs of pain or discomfort and address them promptly
- Warm up and stretch before engaging in physical activity.