Posterior Cruciate Ligament (PCL) Tear

What Exactly Is A PCL Tear?

A PCL tear occurs when the posterior cruciate ligament inside your knee gets torn, damaged, or stretched beyond its capacity. This kind of injury is less common than injuries to other knee ligaments, such as the anterior cruciate ligament (ACL). However, it often occurs alongside other injuries of the knee that involve the ACL, bone fractures, or dislocations.

PCL tears can happen during falls, car accidents, or sports when the knee is hit or bent too far. Depending on how severely torn the ligament is, a PCL tear can lead to pain, swelling, knee instability, and reduced range of motion, ultimately impacting everyday activities.

A Closer Look At The PCL In The Knee

The PCL is a strong band of tissue at the back of your knee. It connects the thigh bone (femur) to the shin bone (tibia). The PCL is responsible for keeping your knee from moving too far backward during movement, preventing dislocations and other injuries.

The PCL works together with the ACL, which keeps your knee from moving too far forward, and the meniscus, which cushions the bones and helps maintain smooth movement. Muscles around the knee and thigh support these ligaments and help control your knee’s movement.

When the PCL tears, your knee may feel unstable or about to “give out”, especially when walking downhill or going downstairs. Other parts of the knee, like the meniscus or muscles, may also be affected during a PCL tear, aggravating pain and knee mobility.

Underlying Factors Behind Knee Ligament Injuries

PCL tears usually happen when the knee is placed under undue force. These injuries are often caused by accidents, sports, or sudden movements that push the knee out of its normal position.

Several different factors can make it more likely you will injure the PCL or other ligaments in your knee:

Trauma Or Direct Impact

One of the most common causes of PCL tear is direct trauma. Sudden undue force or a direct impact pushes the shin bone backward relative to the thigh bone.

A common example is a car accident where the knee hits the dashboard, called a “dashboard injury.” This mechanism of action is responsible for 35% of PCL tears.^[1]

Similar trauma can happen if you fall onto a bent knee or experience a hard tackle in contact sports. These impacts create enough force to stretch or tear the PCL—sometimes alongside other structures in the knee.

Hyperextensions

Hyperextension occurs when the knee is straightened past its normal range of motion, often due to accidents or sports injuries.

This motion stretches the ligaments beyond their limits and puts excessive stress on the PCL at the back of the knee. Hyperextension may occur if you land awkwardly from a jump, trip, or experience a sudden backward motion. These injuries are seen most often in high-impact sports athletes.

Injuries

Sudden movements, turns, or forceful actions during sports and physical activity can put intense strain on the PCL. Common injuries include:

• Sports-Related: Quick stops, fast direction changes, or tackles in sports like football, soccer, and basketball can cause the shin bone to move backward while the knee is bent. In a study published in 2015, soccer injuries accounted for 25% of PCL cases, with the goalkeeper being the most affected role.^[2]
• Twisting Injuries: Ligament tears can happen when rotating the knee forcefully while the foot is planted, especially if combined with a fall or awkward movement.
• Dashboard Injuries: A sudden blow to the bent knee, such as striking a dashboard in a car accident, can push the shin bone backward and tear the PCL.

Underlying Conditions

Existing injuries or problems in the knee joint can increase the risk of a PCL tear, as they weaken the knee’s overall support and stability.

• Torn ACL: A damaged anterior cruciate ligament makes the knee unstable, putting extra strain on the PCL to keep the bones aligned.
• Meniscus Tears: The meniscus acts as the knee’s shock absorber. When torn or worn down, it may change how force is distributed through the joint, leading to more stress on the PCL.
• Chronic Instability: Recurrent knee injuries or weakness can increase the risk of PCL tears, even due to minor impacts or movements.

Symptoms That Shouldn’t Be Ignored

PCL tears may cause symptoms similar to those of other knee injuries. After an impact or forceful movement, it is essential to be aware of specific signs that may indicate a problem with the PCL. Early recognition and prompt care are essential to avoid further complications and support recovery.

• Inside Of Knee Pain: Inside of knee pain is discomfort along the inner joint often caused by ligament or cartilage issues.
• Inside Of Knee Swelling: Inside of knee swelling is fluid buildup on the inner knee, often caused by injury or inflammation.
• Joint Pain And Swelling: Joint pain and swelling are signs of inflammation, often caused by arthritis or injury. Read more about Joint Pain And Swelling.
• Limited Range Of Motion: Limited range of motion is reduced joint movement, often caused by stiffness or injury. Read more about Limited Range Of Motion.
• Stiffness: Stiffness refers to tightness in joints or muscles, often caused by inactivity or inflammation. Read more about Stiffness.

How Physicians Diagnose PCL Tear

Doctors use several steps to ascertain if you have a PCL tear and to exclude other causes at the root of your knee pain. An accurate diagnosis is essential as it will inform treatment decisions to both manage symptoms and support healing.

Common diagnostic tools include:

• History Of Injury: Your physician will ask detailed questions about how your injury occurred, what you were doing at the time, and if you have had any previous knee problems. This helps them better understand the mechanisms of action and determine what components of the knee may have been involved.
• Physical Examinations: The healthcare provider will examine your knee, looking for swelling, tenderness, or looseness by gently moving your leg. Special tests, like the posterior drawer test (a physical examination applying a posterior force to the tibia while the femur is stabilized, and observing for excessive posterior movement of the tibia relative to the femur), help check ligament stability and range of motion.
• Imaging Studies: Imaging tests, such as X-rays and MRI scans, are helpful to gain visibility into the inner aspects of the knee. These tests show soft tissues like the PCL, ACL, and meniscus, helping determine which structures are injured.

Potential Complications If Left Untreated

If a PCL tear is not treated, the knee can slowly lose stability. This ongoing instability can cause more damage to the joint and make daily activities difficult. Over time, this can impact mobility and quality of life.

Potential complications include:

• Chronic Pain and Limited Mobility: Untreated tears often lead to lasting pain, stiffness, and problems with bending or straightening the knee. This can impact your ability to work, perform sports, or, in severe cases, live independently.
• Higher Risk of Falling: Instability puts you at greater risk for falls, especially when using stairs or walking on uneven surfaces.
• Potential Development of Osteoarthritis: Unstable movement in the knee can cause extra pressure and wear on cartilage, increasing the likelihood of degenerative conditions like osteoarthritis over time.
• Trouble Bearing Weight on the Affected Knee: You may find it hard or painful to stand, walk, or engage in normal physical activities due to weakness and discomfort. This can lead to reduced mobility, muscle loss, and reduced function.

Available Treatment Options For Torn Ligaments

Treatment options for PCL tear will depend on the tear severity, the impact it has on your life, and whether other structures of the knee are involved. Pain medications can temporarily ease symptoms, but it is important to address the root cause of your knee pain. For severe injuries that involve the ACL, bones, and muscles, surgery may be considered as an option.

However, in most cases, mild to moderate PCL tears can heal on their own with the right care. This ligament has an intrinsic ability to heal, especially if only mildly damaged.^[3] Here, regenerative treatments aim to support this ability to heal and regenerate damaged tissue.

Common treatment options include:

• Physical Therapy Treatment: Physical therapy is a structured approach using guided movement and rehabilitation techniques that may help support joint function and mobility. Read more about Physical Therapy Treatment.