PCL Tears

A PCL tear occurs when the ligament is overstretched or torn due to a sudden force pushing the shin bone backward relative to the thigh bone. The injury can range from a mild sprain, where only some fibers are damaged, to a complete rupture. The PCL is stronger than the ACL, which means it takes a significant force to cause an injury—commonly a direct impact or trauma. Because of this, PCL injuries are associated with sports accidents, car collisions, or falls where the knee is bent and experiences a sudden force.

A PCL tear may occur alone or alongside other ligament injuries, such as to the ACL, medial collateral ligament (MCL), or meniscus. When multiple ligaments are involved, the injury can be more severe and may lead to long-term knee instability if not properly treated.

The most common cause of a PCL tear is a direct blow to the front of the knee when it is bent. This mechanism is often seen in “dashboard injuries” during car accidents, where the shin strikes the dashboard, pushing the tibia backward. In sports, PCL tears often result from falling on a bent knee or during collisions that force the knee into hyperflexion. Contact sports such as football, soccer, and basketball carry a higher risk.

Other causes can include:

• Sudden changes in direction or pivoting movements
• Landing awkwardly after a jump
• Overextension of the knee joint
• Direct trauma during high-impact sports or falls

The symptoms of a PCL tear can vary depending on the severity of the injury. Some people may notice only mild discomfort, while others experience significant pain and instability. In many cases, symptoms may develop gradually, especially if the injury is partial or if other structures in the knee are compensating.

Common symptoms include:

• Pain in the back of the knee, particularly when bending or squatting
• Swelling and stiffness within the first few hours after injury
• A feeling of looseness or instability in the knee
• Difficulty walking, running, or descending stairs
• A sense that the knee may “give out” under pressure
• Bruising behind the knee or on the upper calf

Some individuals with a mild PCL tear can still walk and even continue sports activities immediately after the injury, mistaking it for a simple sprain. However, untreated PCL tears can lead to long-term instability and early-onset arthritis in the knee.

Diagnosing a PCL tear involves a combination of physical examination and imaging studies. Dr. Collon will evaluate knee movement, stability, and the degree of posterior shift of the tibia relative to the femur. Special tests can help determine the extent of laxity or looseness in the joint.

Imaging plays a crucial role in confirming the diagnosis. X-rays may be used to rule out fractures or bone injuries, while magnetic resonance imaging (MRI) provides detailed images of the ligaments, cartilage, and soft tissues. MRI can determine whether the tear is partial or complete and identify any associated injuries to other knee structures.

When a PCL tear is not properly diagnosed or treated, it can lead to ongoing knee instability and chronic pain. Over time, this instability can cause abnormal wear on the cartilage, increasing the risk of developing osteoarthritis. Patients may also experience muscle weakness, limited range of motion, or difficulty performing activities that require strong knee support, such as climbing stairs or running.

Repeated or severe PCL injuries can also lead to secondary damage to the meniscus or other ligaments, complicating the recovery process.

The long-term outcome for a PCL tear depends on the severity of the injury and how promptly it is addressed. Many patients regain normal function and return to sports or daily activities after appropriate treatment. However, early diagnosis and a structured recovery plan are essential to avoid chronic issues.