The posterior cruciate ligament (PCL) is one of two cruciate ligaments found at the back of the knee. It connects the tibia and the femur and plays a vital role in the maintenance of knee joint mechanics and kinematics– keeping the joints in place and allowing optimal movement. PCL specifically, prevents your knee from moving too far backwards.
PCL injuries rarely occur as they are significantly stronger compared to ACL. They are responsible for less than 20% of knee ligament injuries. It is even rarer for PCL injuries to occur in isolation as they tend to be accompanied by injuries of other ligaments or the meniscus.
PCL injuries manifest on different degrees and are graded accordingly:
Grade 1: mild damage in the form of a stretch but still capable of maintaining joint stability, also known as an isolated PCL injury.
Grade 2: ligament is loose, ability to maintain joint stability is affected, and often referred to as a partial tear.
Grade 3: complete tear or rupture and knee joint is completely unstable. Tend to be accompanied by an ACL injury.
What causes posterior cruciate ligament (PCL) injury?
The rarity of PCL injuries is attributed to the sheer strength of the ligament. It takes a significant amount of impact on the knee for a PCL injury to occur.
Potential causes of PCL injury include:
Direct blow at the knee which could occur from an accident
Being hit in the knee with a heavy object or an object moving at high speed
Hyperextension injury which leads to the stretching of the ligament
What are the symptoms of posterior cruciate ligament (PCL) injury?
Symptoms of PCL injury vary based on the severity of the case, these symptoms include:
Pain that gradually increases
Generally feeling unstable and the sensation of your leg “giving away” or buckling
If you notice any of the symptoms, make an appointment with an orthopaedic specialist to get an accurate diagnosis and treatment.
Dr Puah KL is our Senior Consultant Orthopaedic Surgeon at Artisan Sports & Orthopaedic Surgery. He used to serve the sports service of Singapore General Hospital - the highest volume trauma centre for orthopaedics in Singapore.
Is posterior cruciate ligament (PCL) injury painful?
The level of pain varies depending on the grade of PCL injury incurred.
In the event of an isolated PCL injury (grade 1), patients report no pain or even being aware of a tear. Whereas with more severe PCL injury, pain is present.
Who is at risk of posterior cruciate ligament (PCL) injury in Singapore?
Given that PCL injury is rare, there is no significant risk group. However, the injury may occur more commonly among:
Athletes: specifically rugby players and football players as they tend to be tackled by other players, which can result in a partial or complete tear of their PCL.
How is posterior cruciate ligament (PCL) injury diagnosed?
PCL injuries are diagnosed in the following ways:
Physical examination and medical history: inform your orthopaedist of the potential activities that may have led to the injury such as trauma, exercise, or sports. Physically the area of injury will be examined and several motion tests will be conducted to review the injury.
Imaging tests: magnetic resonance imaging (MRI) or dynamic ultrasonography would be required to confirm if a PCL tear has occurred. It is also the only reliable method to identify PCL injury. X-rays may be ordered if a third-degree tear has occurred or an incidence of fracture is suspected. Usually a specific x-ray, namely a CL stress x-ray is administered.
Arthroscopy:arthroscopy, a minimally invasive procedure would be conducted where a small camera is inserted into the knee joint to visualise the structures inside.
What are the treatment options for plica syndrome in Singapore?
Typically conservative treatments (non-surgery) would suffice for recovery.
Some of the treatment options include:
Rest: you would be advised to observe complete rest to relieve pain and reduce swelling.