Anterior cruciate ligament or ACL injury is one of the common types of knee injury among sports injuries. An anterior cruciate ligament is a strong band of tissue connecting the femur (thigh bone) and tibia (shinbone). Anterior cruciate ligament injuries can occur during physical activities, sports, or any accident that puts pressure on the knee joint. Sudden slow down or direction change during running, pivoting with foot firm on a position, landing awkwardly during a jump or certain sports like football, basketball, skiing, martial arts etc., can cause ACL tear or torn ACL.
One can hear a popping sound or sudden, painful sensation when an ACL injury happens. The knee becomes unstable, swells, becomes very painful and cannot bear weight. Treatment depends upon the severity of the injury. Sometimes rest and rehabilitation exercises can help to get the strength back. Still, sometimes surgery becomes necessary to replace the torn ACL. To understand more about injury, we need to understand the anatomy of our knee.
Anatomy of Knee Joint:
The femur (thing bone), tibia (shinbone) and patella (kneecap) together form the knee joint. The kneecap provides protection to the knee joint. Femur, tibia and patella are connected by ligaments (fibrous connective tissue). There are four primary ligaments: medial collateral ligament or MCL, lateral collateral ligament or LCL, anterior cruciate ligament or ACL and posterior cruciate ligament or PCL. MCL is on the inner side of our knee, and LCL is on the outer side. They control the side-to-side motion of the knee and brace it against any unusual movement.
Anterior and posterior cruciate ligaments are located inside of the knee joint, and they cross each other and form an X. Anterior cruciate ligament is located in the front and PCL is found on the backside. Anterior cruciate ligament and posterior cruciate ligament control the front and back motion of our knee. The anterior cruciate ligament gives rotation stability to our knee. PCL prevents the shinbone from going too far backwards. PCL is more robust than anterior cruciate ligament and therefore sustains injury far less often.
An ACL injury can be graded on a severity scale.
Grade 1 ACL Injury. The ligament is mildly damaged and stretched but can keep the knee joint stable.
Grade 2 ACL Injury. The anterior cruciate ligament is stretched to the point where it becomes loose, also known as a partial tear of the ligament.
Grade 3 ACL Injury. Grade 3 is commonly called a complete tear of the ligament. The ligament is torn in half or separated from the bone, and the knee joint becomes unstable.
Cause of torn ACL
A torn ACL can happen due to many reasons. It is a very common sports injury. Below are some causes of torn anterior cruciate ligament injuries.
- Sudden fall.
- Rapid change of direction during running.
- Stopping suddenly during a running or jogging workout.
- Landing incorrectly from a jump.
- Direct collision in case of a football tackle.
Due to differences in muscular strength, physical conditioning, and neuromuscular control, female athletes have a higher chance of having an ACL injury. Studies also revealed differences in pelvis and lower leg alignment, increased looseness in ligaments, and the effects of estrogen on ligament properties.
Symptoms of an ACL tear
An ACL tear can make a popping sound, and one can feel that the knee cannot bear weight anymore. Other typical symptoms include:
- Pain and swelling. Within 24 hours of the injury, the knee will swell, and the swelling and pain may go away if it is a slight tear. Still, any attempt to return to sports can cause further damage to the knee’s cushioning cartilage (meniscus).
- There will be a loss of full range of motion
- Tenderness at the joint line
- Discomfort while walking
First Aid for torn ACL
See your healthcare provider if the slightest idea of an ACL tear comes to mind. Do not engage in sports or any such activities until a visit to an orthopedic doctor and treatment. The doctor can opt for a physical examination, X-ray, or MRI of the knee. These can confirm the diagnosis and reveal other knee injuries.
First Aid for an ACL tear may include:
- Resting your knee.
- Raising the leg above the level of the heart.
- Applying an ice pack on the knee.
- Use a crepe bandage or compression wrap around the injured knee.
- Using pain relievers, such as nonsteroidal anti-inflammatory drugs.
One also may need the following for additional support:
- Walker or crutches to walk until the swelling and pain get better.
- Using braces to give the knee additional stability.
- Physical therapy to improve joint motion and leg strength.
- A surgical procedure to reconstruct the anterior cruciate ligament.
Some people live and usually function with a torn ACL. But most people find their knees unstable with physical activity.
DO NOT for an ACL injury
- Don’t try to move the knee if the injury is severe.
- Can use a splint to keep the knee straight until you see a doctor.
- Don’t return to activities until you have been treated.
Examination of ACL Injury
Physical Examination for ACL tear:
During a hospital visit, the doctor/doctors will discuss the symptoms and medical history. They will check the injured knee structure and compare them to the non-injured knee structure.
Imaging Tests for ACL injury:
The doctor can ask for an X-ray though it will not show an ACL tear but will rule out any bone damage. Magnetic resonance imaging (MRI) scan provides better images of soft tissues like the anterior cruciate ligament. MRI will help the doctor discover injuries to other soft tissue structures in the knee, such as the meniscus or cartilage.
Treatment of Torn ACL
Treatment for an ACL tear varies on the patient’s condition, activity level, and level of tear – partial or complete tear. A young athlete who is involved in agility sports needs to go for surgery to safely return to sports activities. In contrast, a less active older individual can return to a quieter lifestyle without surgery.
Partial ACL Tear:
The prognosis of a partially torn ACL is generally good, and the recovery and rehabilitation period usually are 3 months. But some patients can still find instability symptoms with partially torn ACL. Therefore, a close clinical follow-up and a complete course of physical therapy can help patients with unstable knees because of a partial ACL tear.
Complete ACL Tear:
Complete ACL tears mostly need surgery, and recovery is impossible without surgery. After a completely torn ACL, it becomes impossible to participate in sports, and some even find it difficult to do daily tasks, such as walking. There are some rare cases where the patient can participate in sports or actions without any symptoms of instability. This variability is because of the severity of the original knee injury.
ACL injuries occur with further damage to the meniscus, articular cartilage, or other ligaments. Secondary damage may occur in patients with repeated instability episodes due to ACL injury. With chronic instability, most patients could have meniscus damage after 10 or more years of the first injury. Articular cartilage lesions are widespread in patients with a 10-year-old torn ACL injury.
Nonsurgical Treatment of Torn ACL:
Continuous physical therapy and rehabilitation restore the knee close to its pre-injury state condition, and the patient also learns how to prevent instability. The doctor may recommend wearing a hinged knee brace for additional support. It may happen that one could suffer another injury to another part of the knee due to instability of the knee joint. Nonsurgical management of ACL tears could be recommended in patients:
- Who has partial tears and there are no instability symptoms
- Who has complete tears but doesn’t experience any symptoms of knee instability.
- Those who are into low-demand sports and are ready to give up high-demand sports.
- People who do light manual work.
- People who live a sedentary lifestyle.
Surgical Treatment of Torn ACL:
ACL tear, along with other injuries in the knee, generally recommends a surgical treatment. One should talk to the orthopedic surgeon about the risks and benefits of surgery, as growth plates can be avoided with specific surgical techniques. ACL tears are generally not repaired using sutures or stitches because repaired anterior cruciate ligaments usually have been shown to fail over time.
A substitute grafting of the tendon can replace the torn ACL. It could be an autograft, where the graft comes from the patient or an allograft, where the graft comes from a tissue donor.
- Patellar, hamstring, or quadriceps tendon autograft.
- Patellar tendon, Achilles tendon, semitendinosus, or posterior tibialis tendon allograft.
Who Should Consider Anterior Cruciate Ligament Reconstruction Surgery?
- Active adult patients involved in sports that require pivoting, turning etc., or jobs that require strenuous manual work are advised to consider surgical treatment. Activity level, not age, also determines whether surgery needs to be considered.
- When a patient has a torn ACL and significant functional instability, there is a high risk of developing damage in other knee areas. Therefore, should be considered for anterior cruciate ligament reconstruction.
- ACL tear, in combination with damage to the meniscus, articular cartilage, collateral ligaments etc., needs surgical procedures. Injury to the anterior cruciate ligament, the MCL, and the medial meniscus requires surgical intervention.
- Surgical treatment may be necessary in cases of combined injuries and produces better outcomes. Meniscus tears may be fixable to a certain extent. Still, it is better if the repair is done with the anterior cruciate ligament reconstruction.
Rehabilitation after anterior cruciate ligament surgery
Physical therapy is crucial for successful anterior cruciate ligament surgery. Anterior Cruciate Ligament reconstructive surgery depends significantly on the patient’s dedication to the rigorous physical therapy needed after the surgery. Today we have newer and improved surgical techniques and stronger graft fixation procedures. Along with proper surgery, physical therapy is used as an accelerated course of rehabilitation.
After the surgery, during the first 7 days, the wound should be kept dry and clean. The emphasis at this point is regaining the ability to straighten the knee and restoring control of the quadriceps.
Icepack or icebag is used regularly to reduce swelling and pain. The surgeon may order a brace to move the knee through its range of motion. Weightbearing status, like crutches, can keep a patient’s weight off the surgical leg.
The rehabilitation goals of Anterior Cruciate Ligament reconstruction are
- Achieve full range of motion of the knee.
- Reduction of knee swelling.
- Strengthening muscles of the quadriceps and hamstring muscles.
The patient can get back to sports or such activities as soon as
- There is no more prolonged pain.
- No more swelling.
- Restoration of the full range of motion of the knee.
- Muscle strength and endurance of the leg are fully restored.
Most patients can return to full sports participation within 6 to 12 months, depending on the patient’s progress, strength, and mechanics. Using a brace while returning to activities is not compulsory, but one may feel more secure wearing one.
Complications after Anterior Cruciate Ligament surgery:
There is a high chance that people may develop osteoarthritis after an ACL injury, and arthritis may occur even after one has undergone ligament reconstruction surgery. Factors like the severity of the injury, any additional damage to the knee joint and activity level after treatment play an important role in whether one will develop arthritis.
Prevention of ACL injury:
Proper training and exercise may reduce the risk of an ACL injury. One should consult a sports medicine physician or an athletic trainer for assessment, instruction and feedback to reduce the risks associated with sports where ACL injury chance is high.
- One should exercise to strengthen the core, which includes the hips, pelvis and lower abdomen.
- Exercises to be done to strengthen leg muscles. Exercises such as hamstring exercises could be practiced to achieve an overall balance and strength of the leg muscles.
- One should be well aware of proper techniques and knee position while jumping and landing from jumps.
- Adequate training should be done to improve technique when performing pivoting and cutting movements.
- Wear appropriate gear according to the sports you into. Right footwear and padding can help one to prevent any accidental injury.
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