A knee dislocation means that the bones in your knee have moved out of place so that the the joint no longer works properly. The dislocation can put pressure on the nerves and blood vessels in your knee and damage them. When your knee is dislocated, you may also have broken bones.
What is the cause?
A dislocated knee is usually caused by:
Suddenly twisting your body while your feet stay in one place
Hitting the knee very hard
Forcing your leg and knee to straighten past a normal position
Your kneecap is more likely to move out of place if:
Your thigh muscles are over- or under-developed.
You have an abnormal knee structure.
You are knock-kneed (knees turn in).
You were born with weak or loose ligaments. Ligaments are strong bands of tissue that connect one bone to another.
What are the symptoms?
Symptoms may include:
Severe pain right after you hurt your knee
Not being able to bend or straighten your knee properly
A change in the shape of your knee that makes it look crooked or out of place
Rapid swelling of your knee
Tingling or numbness in your foot
How is it diagnosed?
Your healthcare provider will ask about your symptoms and medical history and examine you. Tests may include:
MRI, which uses a strong magnetic field and radio waves to show detailed pictures of the knee
Arteriogram, also called an angiogram, which is a series of X-rays taken after your healthcare provider injects a special dye into your blood vessels to look for damage
How is it treated?
A dislocated knee needs treatment right away to prevent permanent damage to the nerves and blood vessels.
Your healthcare provider will put the bones back in the right position. You may need to have a local or general anesthetic to keep you from feeling pain when this is done. A splint or cast will hold the bones in the correct position for several weeks. This prevents your joint from moving while it heals. When the splint or cast is removed, your healthcare provider may recommend stretching and strengthening exercises to help you heal.
Often there is damage to the ligaments and cartilage of the knee when it is dislocated. You may need surgery to repair the ligaments.
How can I take care of myself?
Follow the full course of treatment prescribed by your healthcare provider. In addition:
Keep your knee up on pillows when you sit or lie down.
Put an ice pack, gel pack, or package of frozen vegetables wrapped in a cloth on the injured area every 3 to 4 hours for up to 20 minutes at a time.
Take nonprescription pain medicine, such as acetaminophen, ibuprofen, or naproxen. Read the label and take as directed. Unless recommended by your healthcare provider, you should not take these medicines for more than 10 days.
Nonsteroidal anti-inflammatory medicines (NSAIDs), such as ibuprofen, naproxen, and aspirin, may cause stomach bleeding and other problems. These risks increase with age.
Acetaminophen may cause liver damage or other problems. Unless recommended by your provider, don’t take more than 3000 milligrams (mg) in 24 hours. To make sure you donâ€™t take too much, check other medicines you take to see if they also contain acetaminophen. Ask your provider if you need to avoid drinking alcohol while taking this medicine.
Wear a knee brace if recommended by your provider.
Do the exercises recommended by your healthcare provider.
Ask your provider:
How and when you will hear your test results
How long it will take to recover
If there are activities you should avoid and when you can return to your normal activities
How to take care of yourself at home
What symptoms or problems you should watch for and what to do if you have them
Make sure you know when you should come back for a checkup. Keep all appointments for provider visits or tests.
Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth. Last modified: 2014-10-23 Last reviewed: 2014-09-25
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.