The ACL is an important ligament in our knee that is used to create stability during movements (squatting, walking, running) and non-moving (standing). The ACL’s primary job is to prevent anterior sliding of the tibia on the femur. If the ACL is ruptured, it often increases the risk of other knee damage, such as the meniscus.
Are ACL injuries common?
ACL rupture or tear is a common injury, particularly in young athletes. There are 200,000 cases of ACL tears each year in the US (Spindler, 2008).
What is the mechanism of an ACL tear?
In over 70% of cases, the injury is caused by a non-contact mechanism, such as sudden deceleration combined with changing direction or pivoting, or landing with the knee in nearly full extension after a jump (Hernandez 2006).
Contact (traumatic) mechanisms of injury usually involve a force applied to the front aspect of a fixed lower leg (Hewett 2006).
What are the symptoms of an ACL tear?
The acute injury is frequently characterized by knee pain and an audible ‘popping’ sound at the time of injury.
The injured person presents with knee pain, swelling, haemarthrosis (bleeding into the joint space), instability with further activity and painful range of motion.
How are ACL tears graded?
ACL tears are graded 1-3, with a grade 3 being a full thickness tear.
Are ACL tears more common in girls?
In a study of collegiate athletes, female soccer and basketball players had a 2.7 times higher incidence of ACL injury compared to their male counterparts. Overall, non-contact ACL injuries are 10-20% higher in female athletes than male athletes (18,19,23,24). The risk of ACL injury in female athletes seems to increase significantly during the mid teenage years (25). A recent study found significantly higher incidence of ACL injuries among girls 6-16 years of age than boys of the same age (2).
What are risk factors for ACL tears?
Poor neuromuscular control
Decreased trunk strength
Decreased hip strength
Previous low back pain
Hip abductor weakness
External hip rotator weakness
Valgus knees (knock knee)
Excessive ground reactive forces (very hard unforgiving surfaces)
Assymetric landing patterns
(16,26,27,28,30,34)
Do I need X-rays or imaging?
X-rays are not very effective in evaluation of an ACL injury. MRI is the gold standard and is used to confirm the diagnosis of ACL injury or rupture, and evaluate associated pathology such as articular cartilage injury, and meniscal and associated ligamentous tears; all of which play a role in maintaining stability of the knee (Crawford 2007).
What are the effects of an ACL tear?
Chronic ACL injury can have a profound effect on the knee biomechanics and movement. Common problems include recurrent knee instability (giving way) and symptoms such as intermittent swelling or a locking sensation (Hernandez 2006).
ACL tears are associated with increased risk of secondary osteoarthritis of the knee, regardless of treatment or surgery applied (Øiestad 2009; Rout 2013).
Can the ACL be rehabbed without surgery?
Yes, the knee can be rehabbed without surgery,
Conservative (non-surgical) treatment for people with an ACL rupture can include the use of cryotherapy (ice), continuous pas- sive motion (movement of the joint by a machine), restrictive bracing, electrotherapy (muscle stimulation) and exercises aimed at strengthening and balance. Rehabilitation regimens used for both treatment options commonly use a three-stage progressive programme: acute, recovery and functional phases (Micheo 2010). The acute stage following injury aims to restore range of motion and resolve inflammation. The recovery phase is from approximately three to six weeks, with the aim of improving lower limb muscle strength and functional stability. Finally, the functional stage of rehabilitation (from six weeks onwards) concentrates on returning the individual to previous levels of activity and decreasing the risk of re-injury (Kvist 2004).
While surgical interventions have become commonplace for athletic individuals, initial non-operative (conservative) treatments, based on physiotherapy, are used more commonly in the general population (Linko 2009).
One study found no difference between surgery and conservative treatment in patient-reported knee scores at 2 and 5 years. However, 39% of the participants randomized to the nonoperative treatment group underwent either ACL repair for continued knee instability or meniscus repair within 2 years of their ACL rupture, while 51% did so within 5 years (31).
Treatment Goals
All treatments aim to reduce knee pain and instability and restore function. Reconstructive surgery aims to restore stability to the knee by replacing the torn ACL. In comparison, conservative treatments, such as rehabilitation, aim to improve the muscle function around the knee and to substitute the function of the missing ACL. However, the optimal management strategy following rupture of the ACL remains controversial.
In the short term, reconstructive surgery may improve knee function for those experiencing severe instability in activity or repeated episodes of ‘giving way’, or both. However, all surgery involves an increased risk of complications.
Does fatigue play into ACL injuries?
Fatigue has been related to increase risk of injury in the athletic population [36]. Fatigued athletes do not have as much control over their stability and center of gravity, both of which increase the risk of ACL injury.
Can ACL injuries be prevented?
Non-contact ACL injuries have a large biomechanical and functional aspect that can be improved to decrease risk of ACL tears. The best prevention programs are typically multi faceted and involve plyometrics, strength training, neuromuscular re-education. The younger age that these programs were implemented, the better results. Typical sessions are 20-30 minutes 3x/week.
A recent meta-analysis found an average 56% ACL injury risk reduction in female athletes following injury prevention programs. (42)
If you need help implementing an ACL prevention program, email us at [email protected] we would be happy to work with your team or program.
At Creekside Chiropractic & Performance Center, we are highly trained to treat and manage ACL sprains or tears. We are the only inter-disciplinary clinic providing services to Sheboygan, Sheboygan Falls, Plymouth, and Oostburg including chiropractic, manual therapy, myofascial release, ART (Active Release Technique), massage therapy, acupuncture, physiotherapy, rehabilitative exercise, nutritional counseling, personal training, and golf performance training under one roof. Utilizing these different services, we can help patients and clients reach the best outcomes and the best versions of themselves. Voted Best Chiropractor in Sheboygan by the Sheboygan Press.
Evidence Based-Patient Centered-Outcome Focused
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