Posterior Cruciate Ligament Injury
What is a posterior cruciate ligament injury? A posterior cruciate ligament (PCL) injury is a partial or complete tear of the ligament in the back of your knee. Ligaments are strong tissues that connect bones together. The PCL connects the tibia (shin bone) to the femur (thigh bone). The PCL stops the tibia from sliding too far backward or forward and keeps the knee stable.
What causes a posterior cruciate ligament injury?
Car accidents: PCL injuries in car accidents are often caused by a bent knee slamming into the dashboard. This pushes the shin bone just below the knee and causes the PCL to tear.
Contact sports: PCL injuries are often caused by falling on a bent knee with the foot pointed down. The shin bone hits the ground first and is pushed backward.
Other causes: PCL injury may also be caused by the following:
- Bending the knee too much
- Overextending the knee
- Hard hits on the outer or inner side of the knee while the leg is twisting
What are the signs and symptoms of a posterior cruciate ligament injury? Unlike other ligament injuries, you will not hear a pop, snap, or tear when your PCL is injured. You may not have any signs or symptoms, or you may have any of the following:
- You may have sudden swelling or pain at the back of your knee.
- You may feel pain with kneeling.
- You may feel your knee giving way and you may have a slight limp.
- You may have pain with running, or walking up or down steps.
How is a posterior cruciate ligament injury diagnosed? Caregivers may test the function of your PCL by moving your knee, leg, or foot in different directions. They do this to look for changes in the position of the parts of your knee. This may show a PCL injury or injury to other knee ligaments. Both of your knees may be checked for any abnormal movement. You may need the following tests:
A joint x-ray is a picture of the bones and tissues in your joints. You may be given contrast liquid to help the pictures show up better. Tell a healthcare provider if you have ever had an allergic reaction to contrast liquid.
MRI: This scan uses powerful magnets and a computer to take pictures of your knee. An MRI is used to look for a PCL tear. You may be given dye, also called contrast, before the test. Tell caregivers if you are allergic to dye, iodine, or seafood. Remove all jewelry, and tell caregivers if you have any metal in or on your body. Metal can cause serious injury. Tell caregivers if you cannot lie still or are anxious or afraid of closed spaces.
Arthroscopy: This procedure is used to look inside your knee for a PCL injury. A small incision is made in your knee and a scope is inserted. The scope is a long, bendable tube with a camera and light on the end.
How is a posterior cruciate ligament injury treated? You may only need physical therapy and supportive devices if your PCL injury is mild. You may need surgery if you have a PCL tear or damage to other knee ligaments. You may need any of the following:
Support devices: You may need a splint or knee brace to limit your movement and protect your knee. You may need to use crutches to help decrease your pain as you move around.
Pain medicine: You may be given a doctor's order for medicine to take away or decrease pain. Do not wait until the pain is severe before you take your medicine.
NSAIDs help decrease swelling and pain or fever. This medicine is available with or without a doctor's order. NSAIDs can cause stomach bleeding or kidney problems in certain people. If you take blood thinner medicine, always ask if NSAIDs are safe for you. Always read the medicine label and follow directions. Do not give these medicines to children under 6 months of age without direction from your child's doctor.
Repair: A PCL tear may be repaired by reattaching the torn ligament.
Reconstruction: You may need reconstruction if your PCL cannot be repaired. Your PCL can be replaced with tissue taken from another part of your body, or from a donor.
Physical therapy: A physical therapist teaches you exercises to help improve movement and strength, and to decrease pain.
What are the risks of a posterior cruciate ligament injury?
- Repeated injuries to your PCL can cause long-term damage. This can lead to a weak, unstable knee, even during normal activities. You may feel your knee give way more often. When the PCL is injured, other ligaments of the knee may also be affected. One or more of the menisci (cartilage shock absorbers between knee bones) may also be damaged. Injury to the PCL may cause the ligament to pull off a part of the shin bone.
- Splints, braces, and casts can cause discomfort and limit your usual activities. If you have surgery, you could get an infection or bleed too much. Even with treatment, the knee may not be the same as it was before the injury. Without treatment, a PCL injury can cause you to have a weak knee or problems walking.
When should I contact my caregiver? Contact your caregiver if:
- You have a fever.
- You have questions or concerns about your condition or care.
When should I seek immediate help? Seek help immediately or call 911 if:
- Your toes are cold or numb.
- Your knee becomes more weak or unstable.
- Your pain has increased or returned, even after taking your pain medicine.
- Your swelling has increased or returned.
- Your symptoms are not getting better.
You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.
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