ACL Tears: Causes, Symptoms, Diagnosis, Treatment, and Prevention
An ACL tear is a common knee injury that affects many athletes and individuals who engage in physical activity. The ACL is one of the four major ligaments that stabilize the knee joint and connects the thigh bone (femur) to the shin bone (tibia). Its function is to prevent excessive knee movement forward.
Causes of ACL Tears
The most common causes of ACL tears are sudden stops, sudden changes in direction, jumping, and landing. Soccer, basketball, football, skiing, and gymnastics are some examples. In order to heal an ACL tear, one or more of the following factors may have to be involved:
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A direct blow to the knee or a collision with another player
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A pivot or a cut with the foot planted firmly on the ground
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A landing awkwardly from a jump
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A sudden deceleration or braking
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A poor alignment or biomechanics of the knee joint
Symptoms of ACL Tears
An ACL tear can cause various symptoms depending on the severity and location of the injury. Some common signs and symptoms are:
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A loud pop or a snapping sensation in the knee at the time of injury
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Severe pain and inability to continue activity
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Rapid swelling and bruising around the knee
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Loss of range of motion and flexibility in the knee
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A feeling of instability or giving way with weight bearing on the affected leg
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Difficulty walking or standing on one leg
Diagnosis of ACL Tears
A doctor will inspect your knee to diagnose an ACL tear. They will ask you about your medical history, your symptoms and how you injured your knee. In addition to checking your range of motion, strength, and stability, they may conduct some special tests to assess your ligaments. Some of these tests include:
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In the Lachman test, the doctor bends your knee straight while applying pressure to your inner side with their hand. If you don't move your lower leg, your ACL is intact.
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An intact ACL is determined by the McMurray test, the doctor bends your knee straight while applying pressure to the outer side of your leg with their hand. If there is no movement in your lower leg, the ACL is intact.
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An intact ACL is indicated by excessive movement in your lower leg when the doctor stands behind you and pulls your leg forward.
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During the pivot shift test, the doctor will stand behind you and press down on one side of your pelvis while keeping it straight. If the lower leg moves excessively on one side, the ACL is intact.
A doctor may also order imaging studies such as X-rays or MRI scans to confirm the diagnosis and rule out any other injuries such as fractures or tears in other ligaments.
The treatment options for an ACL tear depend on several factors, such as age, activity level, severity of injury, and personal preference. There are two main approaches: nonsurgical and surgical.
Nonsurgical Treatment
The nonsurgical treatment method is usually recommended for patients with mild or partial ACL tears (grade 1 or 2), who are relatively inactive or sedentary, and who do not have any other knee injuries. Nonsurgical treatment is intended to reduce pain and inflammation, restore knee strength and range of motion, and prevent further cartilage and meniscus damage.
The main components of nonsurgical treatment are:
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Rest: You should avoid putting weight on your injured knee and limit activities that cause pain or instability.
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Ice: You should apply ice packs to your knee for 15 to 20 minutes every few hours to reduce swelling and pain.
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Compression: You should wrap your knee with an elastic bandage or a compression sleeve to provide support and limit swelling.
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Elevation: You should keep your leg elevated above your heart level when lying down to help drain excess fluid from your knee.
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For pain and inflammation, you can take over-the-counter anti-inflammatory drugs such as ibuprofen or naproxen. However, you should consult with your doctor before taking any medication.
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The physical therapist will develop a customized exercise program for you based on your needs. By doing these exercises, you will improve your flexibility, strength, balance, coordination, and proprioception (your sense of where your body parts are in space). In addition to ultrasound, electrical stimulation, and shockwave therapy, physical therapy may also involve other modalities to stimulate tissue healing.
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It is possible to use a hinged sports brace to stabilize your knee during activities that require cutting or pivoting. It is attached to both sides of your knee with metal rods. It has been shown, however, that bracing does not prevent recurrent ACL injuries, and it may cause discomfort or interfere with normal movements. Until you are able to resume normal activities, bracing should only be used for a short time.
Surgical Treatment
It is usually recommended to undergo surgery for patients with an ACL tear (grade 3), active athletes who want to return to their sport as soon as possible, patients who suffer from other knee injuries like torn meniscuses, or patients whose knees give way repeatedly despite nonsurgical treatment. The goal of surgical treatment is to replace the torn ligament with a graft from another part of your body (autograft) or from a donor (allograft). This will restore stability and function in your knee joint.
ACL tears are not always easy to treat. Consult your doctor and weigh the pros and cons of each option before making a decision. Some factors that may influence your decision include:
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Your age: Younger patients tend to have better outcomes with surgery than older patients, as they have more potential for healing and recovery.
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Your activity level: Active patients who participate in sports that involve cutting, pivoting, or jumping tend to benefit more from surgery than inactive or sedentary patients, as they have higher demands for knee stability and function.
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Your injury severity: Patients who have a complete or severe ACL tear tend to have more instability and pain than patients who have a mild or partial ACL tear, and they may require surgery to restore their knee function.
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Your personal preference: Ultimately, the decision is yours to make, based on your goals, expectations, and lifestyle. You should consider the risks and benefits of each option, as well as the costs and time involved.
Prevention of ACL Tears
There are some steps you can take to prevent an ACL tear or reduce its risk, such as:
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Warm up properly before any physical activity
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Wear appropriate footwear that fits well and provides adequate cushioning and support
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Avoid sudden stops, changes in direction, jumping and landing that can stress the knee joint
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Use proper technique when playing sports that involve pivoting, cutting or jumping
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Strengthen your muscles around your knees with exercises such as squats, lunges, step-ups, leg presses, etc.
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Improve your flexibility around your knees with stretches such as hamstring stretch, quadriceps stretch, hip flexor stretch, etc.
