Knee Ligament Injuries (ACL, PCL, MCL, LCL)
What is a Knee Ligament Injury?
A knee ligament injury a sprain of one or more of the four ligaments in the knee, either the Medial Collateral Ligament (MCL), Lateral Collateral Ligament (LCL), Posterior Cruciate Ligament (PCL), or the Anterior Cruciate Ligament (ACL). ACL, PCL, MCL, and LCL injuries are caused by overstretching or tearing of a ligament by twisting or wrenching the knee.
How can you Injure Your Knees?
There are four ligaments located in the knee the stabilize the joint. Anyone of the ligaments in your knee can be injured by running, jumping, twisting or wrenching your knee. You may have heard of someone tearing their ACL, but that is only one possible knee ligament injury, below is a complete list of all the knee ligament injuries you could suffer.
Anterior Cruciate Ligament (ACL) Injury
Your ACL connects the inside of the top of your tibia (shinbone) to the outside bottom of your femur (thighbone) in the front of the knee. It is responsible for stopping the shinbone from sliding in front of your thighbone and FOR controlling the rotation of your knee. An ACL injury occurs when that ligament is stretched or torn and is one of the most common knee ligament injuries.
Posterior Cruciate Ligament (PCL) Injury
Your PCL is the strongest ligament in your knee and therefore the least likely to sustain injury. It connects the bottom of your femur (thighbone) to the top of your fibula (lower leg bone) in the back of your knee. It is responsible for controlling the backwards motion of the knee (extension). A PCL injury occurs when that ligament is stretched or torn and is often called an “overextended knee.”
Medial Collateral Ligament (MCL) Injury
Your MCL connects the top of your tibia (shinbone) to the bottom of your femur (thighbone) on the inside of your knee. It is responsible for providing stability to the inside of your knee. An MCL injury occurs when that ligament is stretched or torn.
Lateral Collateral Ligament (LCL) Injury
Your LCL connects the bottom of your femur (thighbone) to the top of your fibula (lower leg bone) on the outside of your knee. It is responsible for providing stability to the outside of your knee. An LCL injury occurs when that ligament is stretched or torn.
What Causes ACL, PCL, MCL & LCL Injuries?
Knee ligament injuries are most commonly caused from sports injuries, either from landing a jump the wrong way which causes a sharp change in direction from the knee, or a blunt force hit to the knee, such as a football tackle. Knee ligament injuries can occur outside of sports, such as in a car accident where there is a blunt force hit to the knee.
Are There Different Levels ACL, PCL, MCL & LCL Injuries?
There are three levels of severity for all four types of knee ligament injuries:
Mild Grade I Sprain
This is the least severe and occurs when the ligament of the knee stretches, but does not tear. Although this typically does not affect the stability of the knee, it should still be treated, as it can increase your likelihood of a repeat injury.
Moderate Grade II Sprain
The injured ligament of your knee is partially torn, resulting in swelling, pain, and difficulty moving your knee.
Severe Grade III Sprain
The injured ligament of your knee has completely torn, causing your knee to be very unstable and unable to bear weight.
What are Symptoms of ACL, PCL, MCL & LCL Injuries?
Depending on the severity of your knee ligament injury, you will experience pain and swelling and varying levels of the below symptoms:
- Redness and swelling
- Decreased range of motion of the knee
- Difficulty in or inability to put weight on your leg
- A feeling of looseness in your knee
- Looseness in the joint
- When a severe grade III sprain occurs, a popping noise is heard
- When a severe grade III sprain occurs, there can be bleeding under the skin
- Pain, specifically in the area where the ligament/ligaments are injured.
- Occasionally when a Severe Grade III Sprain occurs, there is no pain because the pain receptors are severed
How are ACL, PCL, MCL & LCL Injuries Treated?
Mild grade I and moderate grade II strains can be treated at home and in a clinical setting, but severe grade III strains always require treatment in a clinical setting. For mild and moderate strains, you can try the following home remedies:
- Rest and elevate your knee
- Apply ice
- Avoid activities for at least six weeks
- Compress your knee with an elastic bandage or tape
- Use anti-inflammatory painkillers such as ibuprofen or acetaminophen to ease the pain
- Use a knee brace to help provide support and stability
In addition to the above treatment, seeking treatment from a pt Health physiotherapist will assist in the healing process and help to ensure that the ligament fibres heal correctly, reducing the risk of a future knee ligament injury.
Will I Need ACL, PCL, MCL, OR LCL Surgery?
Severe grade III sprains often require surgery, especially when it’s your ACL or PCL, or if multiple ligaments are torn. Your doctor will make a recommendation to see an orthopedic surgeon who will discuss the options with you. Reconstructive knee surgery takes six months or more to recover from completely, but many people can return to the same level of activity that they were doing before, including high-level sports. If you decide not to get surgery, a custom-knee brace can be used to help the instability in your leg.
Physiotherapy for ACL, PCL, MCL & LCL Injuries
A pt Health physiotherapist can treat all types of knee ligament injuries and can work with patients recovering from knee reconstruction surgery. Physiotherapy treatment for knee ligament injuries can include:
- Functional retraining and activity modifications
- Strengthening and range of motion exercises
- Manual therapy (joint and soft tissue mobilizations)
- Personalized exercise plan
- A custom-knee brace, or splinting
- Fitting for crutches
- Taping the affected area
- Pain relieving modalities such as:
- Therapeutic ultrasound
- Heat and ice therapy
- Electrical stimulation
Will an ACL, PCL, MCL or LCL Injury Heal on its own?
Yes, mild grade I sprains and moderate grade II sprains may go away on their own with at-home treatments including:
- resting the knee
- applying cold therapy
- taking pain-relieving medication
However, if your injury is caused by sport, another knee ligament injury is likely to reoccur without treatment from a physiotherapist helping the ligament fibres heal properly.
Severe grade III sprains and multiple ligament strains will not go away on their own and require an assessment from your doctor and likely surgery from an orthopedic surgeon.
Can you Prevent an ACL, PCL, MCL or LCL Injury?
Because knee ligament injuries typically occur from trauma to the knee, they are hard to prevent. You can, however, take steps to make it less likely:
- Stretch your legs regularly
- Do a light warm up before sports
- Maintain flexibility
- Ease into new exercise routines