PCL Tear

What is a PCL Tear? How is it diagnosed?

What is a PCL Tear?

A PCL tear is a tear or rip in the PCL (posterior cruciate ligament), one of the major ligaments of the knee, that occurs from an injury that stresses the PCL and knee joint. PCL tears are most frequently caused by a motor vehicle accident involving a bent knee hitting the dashboard of a car or a direct fall onto a bent knee. PCL tears are much less common than ACL tears, particularly because of the location of the PCL within the knee and the fact that the PCL is stronger than and about twice as thick as the ACL.

How is it diagnosed?

History & Physical Exam

A thorough history and physical examination by your healthcare provider can help determine whether you have a PCL tear. Your healthcare provider will ask you questions about your symptoms and how and when your symptoms began to get a clearer picture of how your injury occurred. 

In addition to discussing your medical history, your healthcare provider will perform a physical examination to assess your knee for pain, swelling, and mobility. Your healthcare provider will feel the soft tissues around your knee to see if anything is tender to the touch, and bend and straighten your knee to see if your range of motion is affected or if certain motions are painful.

Your healthcare provider will also test the strength of your leg muscles and examine your ability to walk and move your knee joint. If a PCL injury is suspected, your healthcare provider will likely perform specialized tests to examine the integrity of your PCL and overall knee stability. These tests include:

• Posterior Drawer Test: While laying on your back with your feet flat and knees bent at a 90 degree angle, your healthcare provider will use a leg to stabilize your foot while using both hands to grab around your lower leg and attempt to push your shin backward. A positive result in which your shin bone exhibits excessive backward movement of 6 mm or more typically indicates a problem with the ability of your PCL to stabilize your knee joint.
• Posterior Sag Test: While laying on your back, your healthcare provider will lift your leg by holding onto your heel while maintaining both your hip and knee bent at 90 degrees. A positive result in which your shin bone sags down toward the table when your leg is lifted suggests injury to your PCL.
• Quadriceps Active Test (Active Drawer Test): While laying on your back with your feet flat and knees bent at a 90 degree angle, your healthcare provider will use a leg to stabilize your foot. You will then activate your quadriceps muscles and attempt to extend your knee by sliding your foot forward toward your healthcare provider while your healthcare provider provides resistance against this movement. A positive result in which your shin bone sags backward before contracting your quadriceps and then repositions into place with quadriceps contraction suggests injury to your PCL.

PCL tears are graded based on the degree of movement noted with a Posterior Drawer Test. The greater the amount of movement of your shin, the greater degree of PCL damage and overall knee instability. PCL tears are graded according to the following criteria:

• Grade 1 (mild): minor stretching of the ligament although the knee remains relatively stable; 0-5 mm of shin movement due to ligament laxity
• Grade 2 (moderate): partial tear of the ligament without injury to other structures, causing knee instability; 6-10 mm of shin movement due to ligament laxity
• Grade 3 (severe): complete tear of the ligament, often accompanied by injury to the joint capsule or other ligaments of the knee, resulting in significant knee instability; 11-15 mm of shin movement that disrupts the normal alignment of the knee joint

Imaging 

While a thorough medical history and physical examination may be able to provide enough information to suggest that your PCL is torn, imaging studies may be performed to ultimately confirm a diagnosis of a PCL tear. Different imaging methods can be used to examine the tissues and structures of your knee, which include:

• X-Ray: An x-ray is a 2-dimensional image produced by radiation that examines the structure of your bones. Your healthcare provider may order an x-ray to make sure that you do not have a broken bone or to check for signs of arthritis. Because x-rays only clearly produce images of bones, they cannot be used to diagnose a PCL tear.
• MRI: An MRI, or magnetic resonance imaging, is a 3-dimensional imaging scan that is produced by magnetic fields. MRIs more clearly illustrate soft tissues of the body and can be used to assess the integrity of your PCL and surrounding structures like ligaments, tendons, and cartilage. While an MRI is not always necessary, it is often ordered to confirm a diagnosis of a PCL tear.

PCL Treatment Options (Surgical vs Non-Surgical)

Isolated PCL tears (Grade 1-3) typically do not require surgery, although severe tears that also involve injury to other knee ligaments may require surgical repair to improve overall knee function and stability.

Surgery – PCL Reconstruction

Complete (Grade 3) PCL tears that also occur with severe injuries to other ligaments of the knee often require surgical reconstruction. Without surgery, these injuries can result in chronic knee instability and increase the risk of further injury to your menisci, cartilage, or other knee ligaments.

A PCL reconstruction is performed through a knee arthroscopy, a minimally invasive surgical procedure to repair or remove damaged structures within the knee joint. During your PCL reconstruction, your surgeon will use an arthroscope, a tool the size of a pencil with a camera and light attached, to view the inside of your knee joint while using surgical tools to insert and secure a new PCL from a tendon graft and repair other damaged structures.

If you are generally healthy, the surgery will likely be performed in the outpatient surgical setting, so you will not have to stay overnight at a hospital. 

Non-Surgical Management of PCL Injury

Non-surgical management for a PCL tear involves carefully structured and progressive physical therapy to rehabilitate your knee to decrease pain and swelling, restore normal knee joint range of motion, and improve the strength of the muscles that control your hip, knee, and ankle joints to stabilize your leg. 

Most isolated PCL tears have good potential to recover with a specialized physical therapy program to rehabilitate your knee. In the beginning of your rehabilitation, you will most likely have to wear a knee brace and use crutches to walk to protect your knee joint as your PCL heals. 

Resting your knee from physical activity and use of ice, elevation, and compression can also be used to help alleviate pain and swelling. Your healthcare provider may prescribe you medication like nonsteroidal antiinflammatory drugs (NSAIDs) to help control your pain initially after injury, and may consider giving you a cortisone injection into your knee to decrease pain and inflammation.

PCL Tear FAQs

General

How common is a PCL Tear?

PCL tears are much less common than ACL tears, affecting approximately every 2 out of 100,000 people compared to ACL tears affecting approximately every 68 out of 100,000 people.

Treatment Decision

Who is not a good candidate for surgery?

People with significant comorbidities such as heart and lung problems and bleeding disorders may not be healthy enough to undergo any type of surgery and are usually not good candidates for PCL reconstruction. Most people with isolated PCL tears can rehabilitate their PCL with physical therapy and other conservative treatment options and are also not candidates for surgery. Surgery may only be considered for severe PCL tears that also occur with severe injury to other ligaments of the knee.

Can I wait to have surgery?

While isolated PCL tears typically do not require surgery, severe PCL tears that occur with severe injury to other ligaments of the knee often require surgical reconstruction as soon as possible. Waiting too long to have surgery can lead to chronic knee pain, instability, and risk of injury to other structures.

What’s the difference between a Single Bundle and Double Bundle PCL reconstruction surgery?

While the PCL is classified as a single ligament, the structure of the PCL is actually composed of two bundles of fibers fused together, consisting of a larger anterolateral bundle and smaller posteromedial bundle.

With a single bundle PCL reconstruction, a tendon graft is used to reconstruct only the anterolateral bundle of the PCL. With a double bundle PCL reconstruction, two smaller tendon grafts are used to replace each of the two bundles of the PCL individually. The double bundle technique for PCL reconstruction most closely matches the original structure of the PCL and is associated with better outcomes for recovery.

After Surgery

Can I shower or take a bath?

You should avoid taking a bath or submerging your leg in water during the first two weeks after surgery to decrease the risk of your incisions reopening. While you will be allowed to shower, you should avoid getting your incisions wet during the first two weeks of recovery and should use a plastic bag or plastic wrap secured to your leg with tape to keep your incisions and bandages dry.

Will I need a knee brace? What other supplies will I need?

You will need to wear a dynamic force PCL knee brace after your PCL reconstruction. Initially, this brace will need to be locked into extension to prevent your knee from bending in order to allow your reconstructed PCL to heal. You will also need crutches to walk around in the beginning of your recovery and follow weight bearing restrictions until given clearance by your surgeon to fully bear weight through your operated leg. You may also need a shower chair to sit on while you take a shower if you have difficulty standing and maintaining your balance.

How long will I need to wear a knee brace?

You will need to wear a knee brace that will be locked into extension to prevent you from bending your knee for at least two weeks after your PCL reconstruction. Depending on the speed of your recovery, you will be able to unlock the brace within 2-4 weeks but will continue wearing the brace for up to 24 weeks under the guidance of your healthcare provider.

When can I return to work/school?

If your job or school setting is generally sedentary, you can likely return to work or school two weeks after your PCL reconstruction. For jobs that require prolonged standing, walking, or bending, you may not return to work until 12-24 weeks or more depending on your progress with rehabilitation and how physically demanding your job duties are.

How can I minimize scarring?

You can minimize scarring by avoiding picking at your surgical incisions and leaving your stitches or steri-strips in place until they naturally come off. Keeping your incisions clean and dry will also help avoid infection which can delay healing and worsen scarring.

Can I re-injure my PCL? If so, how can I prevent re-injury?

Re-injuring your PCL is possible if you try to return to too much activity too soon without strengthening your leg muscles enough or not allowing your reconstructed PCL enough time to heal. To prevent re-injury, consistent physical therapy visits and progressive exercises over several months are crucial to maximize the strength and stability of your PCL reconstruction.