A PCL tear refers to the rupture, or sprain, of the posterior cruciate ligament within the knee joint. This injury can result from an impact to the front of the knee that forces the joint to bend backwards in an unnatural way.
Medically reviewed by Dr Chaminda Goonetilleke, 2nd Jan 2022
PCL injury symptoms
The symptoms typically associated with a PCL injury are:
- Acute knee pain that begins suddenly at the time of injury.
- Over time, this pain may extend into the back of the lower leg.
- Swelling might appear in the knee joint, but it could be minimal.
- The knee might also feel unstable like it could give way, particularly when walking downstairs.
Diagnosis & assessment
In instances where your knee exhibits severe pain and swelling, a comprehensive examination may not be feasible. Once the pain and swelling diminish, it becomes easier for your physiotherapist to examine the knee thoroughly.
To diagnose a posterior cruciate ligament injury, a professional therapist might perform various knee assessment tests. These could include the posterior draw test and the reverse Lachman’s test.
Posterior drawer test
The posterior drawer test entails pushing the tibia (shin bone) backwards while the knee remains bent. If the tibia shifts back further than it does on the uninjured side, the test result is positive.
Posterior sag test
The posterior sag test evaluates laxity in the PCL. A positive test is indicated by the tibia dropping down and forming a sag or indent at the front of the upper shin. Remember, it’s crucial to always compare one knee with the other.
Skyline test
The skyline test checks for any displacement or sag by keeping the tibia parallel to the floor. This can indicate the extent of the injury and guide the appropriate course of treatment.
How bad is my PCL injury?
- Grading System: We use a grading system to classify PCL injuries into three levels, with level 3 representing the most severe. The extent of backward tibial displacement signifies the severity of the injury, which increases if the PCL is partially or completely torn. In the most extreme cases, the ligament might get avulsed, meaning it’s completely detached from the bone.
- Diagnostic Imaging: To thoroughly evaluate the damage, your doctor or physiotherapist may rely on imaging techniques such as MRI scans and X-rays. These tools provide a comprehensive view of your knee, helping determine the exact nature of your PCL injury.
What causes a PCL injury?
Though PCL injuries occur less often than anterior cruciate ligament injuries due to their more robust nature, they primarily result from direct blows to the front of the bent knee. Such impacts can happen during head-on collisions, tackles, or even falls.
These injuries frequently accompany other damage within the knee joint, including lateral meniscus tears and articular cartilage impairment.
Treatment for posterior cruciate ligament sprain
Immediate Care: The PRICE Protocol
Immediate first aid following a knee injury involves the application of the PRICE principles – Protection, Rest, Ice, Compression, and Elevation.
Cold Therapy
As an immediate response to the injury, applying cold therapy and compression wrap for 10 to 15 minutes every hour can be beneficial. The frequency can be reduced as symptoms improve. This acute phase typically lasts 24 to 48 hours but might extend longer for severe injuries.
Avoid direct contact of ice with the skin to prevent ice burns. Instead, use a wet tea towel or, ideally, a commercially available cold compression wrap.
Knee Support
In the early to mid stages of recovery, wearing a knee support or brace helps protect the joint. A hinged knee brace offers substantial support. The most effective types are those that limit knee flexion, thereby protecting the PCL and preventing over-straightening of the knee.
Taping
The goal of PCL taping is to provide support for the ligament, preventing the knee from hyperextending during the healing process. It also offers support and confidence during rehabilitation.
After these immediate response steps, two treatment paths exist: conservative treatments and surgery. The choice depends on the severity of the injury and the individual’s needs and lifestyle.
Surgery for PCL injury
Renowned Orthopaedic Surgeon Mr Richard Villar, with his experience as the former Surgeon to the British Army Special Air Service Regiment, shares insights into posterior cruciate ligament surgery.
While PCL injuries often resolve without surgery, severe cases, especially those involving damage to other knee parts, might require surgical intervention. Non-surgical treatments, such as physiotherapy and strength-building exercises, are the first line of treatment for a PCL rupture. If these don’t restore knee stability, braces may be used before resorting to surgery.
PCL reconstruction surgery, similar to an ACL operation, uses a bone-tendon-bone graft to create a new ligament. Patients with PCL injuries generally recover well and can return to their previous sports activities. However, adherence to a strict rehabilitation program greatly influences this recovery success.
Despite a relatively quick initial recovery from PCL reconstruction surgery, returning to sports can take time. A minimum of six months to a year is recommended for a complete recovery.
