Knee Dislocation Specialist

Are you an athlete who participates in contact sports like football, rugby or mixed martial arts? If so, you may be at risk of a knee injury or of dislocating your knee joint. Knee dislocations need immediate medical attention and should be treated by an orthopedic expert. Doctor Riley J. Williams provides diagnosis as well as surgical and nonsurgical treatment options for patients in Manhattan, Brooklyn, New York City and surrounding areas who have sustained a knee dislocation injury. Contact Dr. Williams’ team today!

What is a knee dislocation?

The knee has three bones within the knee joint known as the femur (thigh bone), tibia (shin bone) and patella (kneecap) These bones move together as a hinge-type joint, and provide a basis for leg  strength and knee range of motion. A knee dislocation occurs when there is a disruption of the ligaments between the femur and the tibia, causing an abnormal relative positioning of the tibia and femur of the knee joint. Knee dislocations are often caused by a traumatic injury which forces the bones in the knee joint out of place. Knee dislocations can be very painful and often include injury to the surrounding soft-tissue structures of the knee including the ligaments and cartilage. Dr. Riley J. Williams is an orthopedic knee specialist serving Manhattan, Brooklyn, New York City, NY and surrounding areas. He has extensive experience in diagnosing and treating knee dislocation injuries.


Knee Dislocation

Are knee dislocations and patella dislocations the same thing?

A dislocated knee is different from a dislocated or subluxated patella (kneecap). A patellar subluxation occurs when the patella slips partially out of place; a patellar dislocation occurs when the patella moves completely out of place relative to the femur. While still painful, patella instability events are less traumatic, and do not involve the disruption of the femur, moving out of alignment with the tibia. Both conditions are serious, and Dr. Williams should be consulted to avoid further injury and continued dislocations.

How does a knee dislocation injury occur?

The knee joint allows us to flex and extend the knee and perform daily activities like walking and sitting. A knee dislocation injury is typically occurs as a result of an abrupt and violent trauma. Car accidents, falls or contact sport trauma can impart high forces to the knee and result in a knee dislocation.

There are 4 ligaments supporting the function of the knee that can be disrupted or injured with a knee dislocation:

  • Anterior cruciate ligament (ACL)
  • Posterior cruciate ligament (PCL)
  • Medial collateral ligament (MCL)
  • Lateral collateral ligament (LCL)

If the knee fully dislocates, usually 3 of the 4 major knee ligaments may tear. Partial dislocations can cause significant multi-ligamentous injuries as well.

Causes of knee dislocation may include:

  • Car accidents – dashboard injuries
  • Severe, high impact falls
  • High-impact sports injury
  • Abrupt knee twist or misstep

Who is at risk for a knee dislocation injury?

Knee dislocation injuries can occur at any age; active and inactive individuals can both be affected. Less than 0.5% of all joint dislocations are knee dislocations, making them a much less common injury. There are a number of factors that increase the risk of a knee dislocation injury, including:

  • A previous knee dislocation injury.
  • Direct trauma to the knee in an area that has been injured previously.
  • Individuals experiencing imbalance or weak muscles in the leg.
  • Women can be at higher risk for a knee dislocation injury. Women tend to land differently (more straight-legged) than men, and their knees sometimes tend to fall inward on landing, bending, jumping and pivoting. The force is greater and can be unevenly distributed.
  • Tall stature can be a risk factor for knee dislocation.

What are the symptoms of a knee dislocation injury?

Individuals in the New York area who experience a knee dislocation injury often report the following symptoms:

  • Hearing a “popping” sound at the time of the injury
  • Visible swelling of the knee joint
  • Severe pain in the knee
  • Deformity and/or bruising of the knee joint
  • The lower part of the knee looks shorter and misaligned
  • Inability to move the knee
  • Altered nerve function or sensation below the knee joint

How is a knee dislocation injury diagnosed?

Dr. Williams will inquire about the circumstances leading up to the injury and perform a physical exam of the injured knee. He will assess the extent of the damage by doing any of the following:

  • Checking the blood pressure in the leg. An ABI (ankle-brachial index) test will compare the blood pressure in your arm to that in your ankle. A low ABI measurement indicates poor blood flow to your lower body.
  • Assessing your sense of touch. Dr. Williams will assess the feeling in the injured leg versus the non-injured leg
  • An ultrasound or a CT angiography. Both of these tests will provide more specific details of the injury.
  • Checking nerve conduction. EMG (electromyography) tests and NCV (nerve conduction velocity) tests measure the function of the nerves in the knee.
  • Assessing skin color and temperature. If the skin on your leg is cold or changing colors, that can indicate blood vessel problems.
  • Taking an X-ray. Williams may also take an X-ray of the joint, which will confirm the dislocation, and can reveal broken bones or other damage to your joint.

What is the treatment for a knee dislocation injury?

Treatment for a dislocated knee begins with making sure the leg is not experiencing serious nerve or vascular injury. If the knee is out of joint at the time of presentation to the doctor, a reduction will be done to put the knee “back in place”. A reduction will begin as Dr. Williams administers a sedative, then moves the leg to cause the knee to return to its proper position. Once the reduction is complete, the knee is placed in a brace to stabilize it and keep the knee from moving. Dr. Williams will then determine if surgery is needed. If there is severe damage to ligaments, blood vessels, or nerves surgery may be necessary.

Not all knee dislocation injuries require surgery. Conservative treatment that immobilizes the injured joint can be an option if the following conditions are true:

  • The joint appears very stable after going through reduction.
  • There is no blood vessel or nerve damage present.
  • The MCL and LCL collateral knee ligaments are intact.

If the treatment is surgical or non-surgical, a knee dislocation will require further rehabilitation and physical therapy. Specific rehabilitation protocols will depend on the seriousness of the injury and initial treatment. Dr. Williams will work with you to determine what kind of rehabilitation program is right for you.

Surgical treatment of a dislocated knee injury:

The goal for surgery on a dislocated knee is to restore knee stability and normal function; this is done by repairing or reconstructing the damaged knee ligaments. Surgery for a dislocated knee may also include:

  • ACL Repair or Reconstruction
  • PCL Repair or Reconstruction
  • MCL Repair or Reconstruction
  • Posterolateral Corner Repair or Reconstruction
  • LCL Repair or Reconstruction

For more information on a knee dislocation injury and the treatment options available, please contact the office of Riley Williams, MD, knee specialist serving Manhattan, Brooklyn, New York City, NY and surrounding areas.  


HSS Sports Medicine Institute West Side
610 W 58th Street
New York, NY 10019

HSS Brooklyn
148 39th Street, 7th Floor
Brooklyn, NY 11232

Office Hours

Monday-Friday: 9:00 am – 4:30 pm
Fax: 212-774-2895