Posterior cruciate ligament (PCL) injury

Some of the symptoms of a PCL injury are:

• Knee pain: Knee pain due to a PCL injury can be mild to moderate. Usually, it is not as sharp as the pain experienced in an ACL tear.
• Swelling: The knee would be swollen as a result of the injury as is common with most sprains and ligament tears.
• Inability to walk or run: A person with a PCL injury would find it difficult to put all their body weight on the affected knee, resulting in a limp, or not be able to stand up straight, as the affected knee may give a feeling of not being stable enough.

Some common causes of PCL injuries are:

• Accidents: Direct impact on the knee—for example, due to an object hitting the knee or the knee hitting the dashboard in a car accident
• Sports: A PCL injury can also be the result of a fall in which the person lands on their knee(s), or there is an impact on the bent knee when the top part of the shinbone is hit. (Read more: Workout injuries)

While PCL injuries are usually acute (sudden onset), a tear or weakening of the PCL can also occur over time because of weak knee joints due to a pre-existing health condition.

Read more: Running injuries

As mentioned earlier, PCL injuries are rare compared with other knee injuries. The anterior cruciate ligament (ACL), the patellar tendon and the meniscus cartilage, which are all located around the knee joint, are more susceptible to injuries and tears than the PCL.

Having said that, injuries are often the result of a chance incident. So, preventing them isn't always possible. You can try the following to minimise their impact, though:

• Sports injuries can be avoided by strengthening the muscles around the knee joints, by performing dedicated exercises along with running and other movements.
• Strengthening the knee joint also requires strengthening of the muscles in the thighs and calves. This helps the tissues and ligaments around the knee joint to remain in good health, and therefore be less prone to injuries.

Read more: Leg curl exercise

Unlike ACL injury which is extremely painful, PCL injury may cause mild to moderate pain or discomfort. People with a PCL injury may complain that their knee is "not feeling right", with knee pain that comes and goes but doesn’t hinder running or playing sports too much. This often results in a delay in visiting the doctor to get the problem checked out.

Once patients do go in for a checkup, the doctor will begin by asking questions about how the patient hurt their knee. This will help the doctor understand the kind of impact the patient might have suffered.

A physical exam will follow which will include examining both the knees to understand the subtle differences in the structure of both the joints.

The doctor will then check for swelling, pain, tenderness, movement and other visual cues.

The doctor will also bend and straighten the affected knee to check the discomfort and range of movement.

The doctor may also recommend imaging tests such as X-rays and an MRI scan to assess the exact location and extent of the damage: whether it is a minor stretch or a tear, or whether the injury has also affected any other part of the knee joint such as a fracture to the bone to which the ligament is attached.

It is not a good idea to put your weight or any unnecessary pressure on your knee immediately after an injury. Instead, use ice packs to bring down any pain and swelling around the joint, put pressure (compression) around the knee with a bandage or a heat compress, and elevate the injured leg to minimise the pain. This process is known as RICE, a method that must be employed even before visiting a doctor.

PCL injuries are divided into three different grades, based on the degree of the injury. A suitable treatment plan is devised depending on this degree. In most cases, surgery can be avoided in the case of a PCL injury, and common over-the-counter pain medications can help in bringing down the pain, swelling and discolouration.

Physical therapy may also be advised—the therapy may be extensive, based on the extent of the injury, as such a treatment method can help in restoring the function of the knee, strengthen it and help you gain stability in the affected joint.

Surgery is performed when there is a complete rupture of the PCL, or it has been torn along with another ligament or tissue around the knee joint. In severe cases, the surgery may include a reconstruction of the ligament due to the extensive damage caused, while recurring instances of PCL injuries are also instances where surgery is needed.

Read more: ACL reconstruction surgery

While a sprain or partial rupture of the PCL may not require extensive treatment, it is recommended to take it easy and take all precautions before resuming the activity which caused the injury. In the case of a surgery, it may require months of rehabilitation before a person can resume training or performing other activities that require the full stability of the affected knee.