Knee

Torn Posterior Cruciate Ligament

What it is
The posterior cruciate ligament is located in the back of the knee. It is one of several ligaments that connect the femur (thighbone) to the tibia (shinbone). The posterior cruciate ligament keeps the tibia from moving backwards too far.

An injury to the posterior cruciate ligament requires a powerful force. A common cause of injury is a bent knee hitting a dashboard in a car accident or a football player falling on a knee that is bent.

Anatomy
Two bones meet to form your knee joint: your thighbone (femur) and shinbone (tibia). Your kneecap sits in front of the joint to provide some protection.

Bones are connected to other bones by ligaments. There are four primary ligaments in your knee. They act like strong ropes to hold the bones together and keep your knee stable.

Collateral ligaments
These are found on the sides of your knee. The medial collateral ligament is on the inside and the lateral collateral ligament is on the outside. They control the sideways motion of your knee and brace it against unusual movement.

Cruciate ligaments
These are found inside your knee joint. They cross each other to form an "X" with the anterior cruciate ligament in front and the posterior cruciate ligament in back. The cruciate ligaments control the back and forth motion of your knee.

The posterior cruciate ligament keeps the shinbone from moving backwards too far. It is stronger than the anterior cruciate ligament and is injured less often. The posterior cruciate ligament has two parts that blend into one structure that is about the size of a person's little finger.

Cause
An injury to the posterior cruciate ligament can happen many ways. It typically requires a powerful force.

A direct blow to the front of the knee (such as a bent knee hitting a dashboard in a car crash, or a fall onto a bent knee in sports)

Pulling or stretching the ligament (such as in a twisting or hyperextension injury)

Simple misstep

Symptoms
The typical symptoms of a posterior cruciate ligament injury are:

• Pain with swelling that occurs steadily and quickly after the injury
• Swelling that makes the knee stiff and may cause a limp
• Difficulty walking
• The knee feels unstable, like it may "give out"

More information.

Source from AAOS, Viewmedica, WebMD