Anterior Cruciate Ligament Injury
(ACL Sprain or Tear)
The anterior cruciate ligament, more commonly referred to as the ACL, is the ligament found in the centre of the knee. The ACL connects your femur (thigh bone), above the knee, to the tibia (shin bone), below your knee.
The anterior cruciate ligament and the posterior cruciate ligament (PCL) cross on the inner part of the knee joint. They bond the upper and lower parts of the leg together and stabilize the knee by limiting the rotation and the forward and backward movement of the joint.
Minor ACL Sprains or Tears
Changes in direction, an awkward twist, or over stretching the knee can cause the ACL to sprain or tear. Minor sprains may not be noticed immediately but rather appear a few hours later with pain and swelling. The knee may feel unstable to walk upon and may lock during movement.
Serious ACL Tears or Ruptures
More serious tears or ruptures of the ACL often result from sudden twisting and turning of the knee or from a blow to the knee. These tears are often accompanied by a popping sound. Swelling in the knee usually gets worse for several hours following an ACL tear, with the most rapid swelling occuring within the first 4 hours. You may feel as though something has snapped or simply feel like your knee has given out.
Some ACL tears caused by a blow to the knee are accompanied by meniscus and medial collateral ligament tears. When this occurs, it's referred to as the "unhappy triad".
When the ACL is torn, the mechanics of the knee change and create abnormal pressure on the meniscus and articular cartilage of the femur and tibia. As a result, injury to the meniscus can also occur if the ACL is left untreated. Once the meniscus is injured, the risk of osteoarthritis increases sharply. Therefore, when you have an ACL injury, it is important to modify or limit activities that increase stress on the knees until your ACL is treated and healed.
Who is at Risk?
ACL injuries account for more than two-thirds of all knee injuries among skiers and often occur during a fall when the tibia is pushed forward below the femur. Participating in other sports such as volleyball, football, soccer, basketball, and racket sports can also increase your risk of an ACL injury.
Women experience ACL tears 7-8 times more frequently than men due to hormonal and anatomical differences. Women tend to have stronger quadricep muscles at the front of the thigh compared to their hamstrings at the back of the thigh. This creates an imbalance that can increase the stress on the ACL when landing a jump.
Once the ACL has been damaged, an individual's risk of developing osteoarthritis (degeneration of the joint cartilage) later in life is 9 times higher.
Diagnosis
To diagnose an ACL tear, the doctor will move the knee in several positions and examine the knee strength and stability. Common exams used to diagnose an ACL injury include:
- Palpation and Observation is often the first step in diagnosing. The joint will be examined for swelling, bruising and deformities. Next the doctor pressing lightly on the knee to check for the degree of tenderness, swelling and warmth. Some tenderness usually indicates a mild, or grade 1, sprain and acute pain indicates a more serious injury such as a tear.
- The doctor will also assess the range of motion at the knee. You will be asked to bend and straighten your knee and then the doctor will bend it for you to check for limitations due to pain and swelling.
- Pivot Shift Test - While you are laying down, the doctor turns your foot with your leg extended, applies pressure to the outside of the knee and then bends your knee. If your shinbone shows signs of instability, an ACL tear is diagnosed.
- Lachman's Test - While laying down with your leg bent at a 30-degree angle. The doctor holds your thigh in one hand and top of the shin in the other while moving the tibia forward and backward. If the leg moves loosely without reaching a firm endpoint of its forward motion, an ACL tear is diagnosed.
- Anterior Drawer Test - The doctor will ask you to lay down with your knee flexed 80-90 degrees (hip at approximately 45 degrees)and your hamstrings relaxed. With your foot stabilized, the doctor will grip the tibia with both hands just below your knee and pull it backward and forward to compare movement with your uninjured knee. If the endpoint is not firm when the leg is pulled forward, an ACL tear is suspected.
After a physical exam has been completed, an x-ray may be required to rule out the possibility of a bone fracture. A magnetic resonance imaging (MRI) scan may also be done to determine the extent of the ACL injury and to discover whether the menisci or any other ligaments have been damaged.
An arthroscopy may also be used to allow the doctor a look at the ligament. A tiny camera is inserted into the knee and the doctor can use a small surgical instrument to gently tug at the ACL to determine the extent of the damage. An arthroscopy can be performed on an outpatient basis.
ACL Treatments
Immediate treatment of the ACL injury include cold compression therapy and elevation of the knee. Resting the injured knee and avoiding use of the knee is also important to healing. Continued treatment differs from case to case depending on the degree of instability in the knee and the patient's activity level. Treating an ACL injury with ultrasound therapy and Blood Flow Stimulation Therapy (BFST®) will speed healing and improve the function of the knee so you can return to your normal activities. Once the ACL has improved and activities can be resumed, you will first want to build muscle strength around the knee under the guidance of a physical therapist.
Cold Compression Therapy
Using cold compression immediately following an ACL sprain or tear reduces pain and swelling and reduces the tissue damage that occurs with soft tissue injuries like ligament tears.
The Knee Freezie Wrap® allows you to treat yourself in an effective and convenient way following an ACL injury, if re-injury occurs (which is common due to the instability of the knee), or following surgery if it is required.
Cold Compression Therapy works by interrupting and slowing nerve and cell function in the damaged area. This is important because once blood vessels are damaged, they can no longer carry oxygenated blood to the damaged ACL and cells begin to break-down.
The deep cold provided by the Knee Freezie Wrap® slows cell function thereby reducing cellular break-down. Furthermore, because the cold wraps serve to numb the nerves, the wraps also reduce pain! The Knee Freezie Wrap® uses a deep cold gel pack that is charged in the fridge not the freezer so there is no risk of cryoburn (cold burn to the skin) like ice and freezer ice packs can cause.
Ultrasound Therapy
Individuals with severely torn ligaments often require surgery as part of their healing process. More often though, individuals with mild or moderate tearing require physiotherapy. A common technique used in the treatment of ACL injuries by physiotherapists is ultrasound. Ultrasound is a healing technique that has been in existence around the world for many decades. Ultrasound reduces swelling and pain in the knee. At the same time it also increases the blood supply to the affected area stimulating tissues and increasing the rate of healing.
Ultrasound Therapy increases tissue elasticity while promoting the flow of blood (filled with vital oxygen and nutrients) to your injured ACL. This cleans the injured area by getting rid of damaged tissue and reducing the inflammation surrounding the ACL and opening up the blood vessels to begin healing.
During the healing process, scar tissue builds on the ligament and can attach the ACL to the PCL or other surrounding tissue in the joint, limiting the flexibility in your knee. Fortunately, you can treat your ACL with therapeutic ultrasound to soften scar tissue and improve your range of motion.
Not only does ultrasound aid in the duration of healing, but it helps to prevent long term complications. Pain, scar tissue, lack of mobility and arthritis are some of the more common long term complications from an ACL injury. By treating your ligament with ultrasound, scar tissue is softened reducing the risk of chronic problems in the future.
For those who suffer from long term complications of existing anterior cruciate ligament injuries, ultrasound can help. Ultrasound therapy can help to break up scar and fibrous tissue in the affected area.
Ultrasound can also be used to administer therapeutic medicines into the body. This is a process known as phonophoresis. Ultrasound with phonophoresis is rapidly becoming more popular than ultrasound therapy alone.
Phonophoresis can be received using a MendMeShop® Ultrasound Therapy System. The treatment is safe, easy, painless, and generally requires between 5 - 10 minutes. It is based on a form of deep tissue therapy, which is generated through high frequency sound waves (that we can not hear). These waves send vibrations deep into your body and slightly increase the temperature of your soft tissue cells. The waves are delivered through a hand held transducer and conductive gel that are used together in a slow, circular motion on your skin over the injured area.
Once the inflammation and swelling of an ACL tear has been alleviated, nourishing and strengthening the ligament tissue is recommended. Using Blood Flow Stimulation Therapy will speed your recovery and heal your ligament more completely preparing it for leg strengthening exercises. Talk to your doctor or physical therapist to find out which exercises are appropriate for your situation.
Blood Flow Stimulation Therapy
After the inflammation and swelling is gone you can begin to treat your ACL tear with Blood Flow Stimulation Therapy, or BFST®. BFST® increases the amount of blood that flows naturally to your knee to nourish cartilage, tendons, ligaments and muscles to speed healing.
By treating yourself with Blood Flow Stimulation Therapy you can increase your body's blood supply to the knee and your body's natural healing power. In addition, the fresh blood flow whisks away dead cells and toxins that have built up from the injury leaving the area clean and able to heal faster. Our Knee Inferno Wrap® provides effective, non-invasive, non-addictive pain relief and healing with no side effects.
During your recovery, it is wise to modify and/or eliminate any activities that cause pain or discomfort in your knee until your pain and inflammation settle. Taking the time to care for your knee properly will have your knee back to normal faster and allow you to get back to the activities you enjoy.
Surgery and Recovery
If an injured ligament does not strengthen appropriately or an athlete continues to experience the knee giving way, arthroscopic surgery and ligament reconstruction may be necessary.
If reconstruction of the ACL is required, using these therapies prior to surgery will reduce further damage and improve the health of the ACL and surrounding tissue so the surgery is less invasive.
Using these therapies after surgery will control pain and swelling, reduce tissue damage, speed healing and treat the scar tissue resulting from the healing process. You will have a healthier knee with a greater range of motion than if your recontructed ACL was left untreated.
Activities should set out to promote healing, increase flexibility in the knee and strengthen surrounding muscles. Your physical therapist will probably set up a "passive range of motion" program, and put you in a hinged knee brace for a month or two to prevent hyperextension or hyperflexion in the knee.
An important point for ACL patients to remember after surgery is that every effort must be made to increase range of motion and flexibility at the knee. Weakness in the knee can usually be eliminated by extra strengthening exercises, but increased stiffness can sometimes be permanent if not corrected by further surgery.
Not only will ultrasound reduce the pain and inflammation in your knee, but will help increase the range of motion in your joint, reduce post operative scar tissue and increase flexibility in the surrounding muscles, tendons and ligaments.
Ask your physical therapist about ultrasound and if it's right for your reconstructed ACL! As with all medical devices, make sure your physician is aware of any treatment plan you decide to take.
Preventing Further ACL Injuries
To prevent knee injuries it is recommended that you gradually increase the intensity of any exercise or activity when you begin and to be aware of the movement of the knee during activity.
A knee that is supported by strong quadriceps and hamstring muscles is less prone to injury, therefore, regular exercise and maintaining good physical condition, particularly when participating in sports such as volleyball, football and skiing are also excellent ways to avoid ligament injuries. If your knee is unstable or weak, wearing a brace during exercise and activity can reduce the risk of reinjury of the ligament while your knee is regaining strength.
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