Key Points about Knee Dislocation
- A dislocated knee occurs when the leg bones are forced out of alignment at the knee joint.
- Common causes of knee dislocations include falls, contact sports, and car accidents.
- A knee may be dislocated if there was a “pop” sound at the time of the injury, and if there is extreme pain, bruising and swelling in the knee.
- Knee dislocation is a serious medical emergency that requires immediate care.
- Seek emergency medical attention if you think you may have a dislocated knee.
Knee dislocation occurs when the leg bones, which meet at the knee joint, are forced out of alignment. This misalignment often results from a high-impact trauma to the knee joint, such as from a fall, car accident or sports injury.
Symptoms of a dislocated knee include hearing a “pop” at the time of the injury, and experiencing extreme pain, bruising and swelling in the affected knee.
A dislocated knee is a serious injury that requires immediate medical attention. Seek emergency medical care if you have extreme pain in the knee following an injury, if there is a noticeable deformity, or if your foot is numb.
Knee dislocation causes
Knee dislocations occur when the leg bones become misaligned at the knee joint.
Common causes of dislocated knees include:
- Contact sports
- Car accidents
Knee dislocation risk factors
You may be at an increased risk of dislocating a knee if you:
- Have had a previous knee dislocation
- Experienced direct trauma to the knee
- Have weak or imbalanced muscles in the leg
- Are a woman
- Are particularly tall
Knee dislocation symptoms
Signs and symptoms of a dislocated knee include:
- Hearing a “pop” when the injury occurs
- Severe pain
- Swelling and bruising in the affected knee
- An inability to move the knee
Knee dislocation complications
A dislocated knee can lead to blood vessel and nerve damage.
If left untreated, a dislocated knee can lead to:
- Limited range of motion in the knee
- Tissue atrophy and tissue death, which can ultimately require an amputation above the knee, in severe cases
Knee dislocation diagnosis
When evaluating a dislocated knee, your doctor will assess the extent of the damage by examining the knee and its surrounding area, including the:
- Blood vessels
Your doctor will also order one or several of the following imagine procedures, to further assess the nature of the injury:
- X-ray to visualize bone damage
- CT scan to visualize bone damage in detail
- MRI scan to visualize soft tissue damage
Knee dislocation treatment
When receiving treatment for a dislocated knee, the first line of treatment is to minimize and prevent any further damage to the nerves and blood vessels surrounding the knee.
Once a doctor has taken measures to prevent further damage, the next line of treatment is to address the existing damage. Most dislocated knees will require surgery, to repair damaged:
The type and extent of the surgery will vary depending upon the nature of the injury.
When to seek care
Seek emergency medical care if you think you may have a dislocated knee.
After receiving treatment for a dislocated joint, your doctor will provide a recovery timeline and rehabilitation program. This program will include physical therapy exercises to help restore a full range of motion and full strength in the knee.