POSTERIOR CRUCIATE LIGAMENT (PCL) TEAR

OVERVIEW

The knee joint is a hinge joint that is stabilized by multiple ligaments. The cruciate ligaments are the important stabilizing ligaments in the knee joint that are arranged in ‘X’ formation in the joint space.

The two ligaments are the Anterior cruciate ligament (ACL) and the Posterior Cruciate ligament (PCL). The PCL provides stability by preventing excessive posterior movement of the tibia under the femur.

The incidence of PCL is less than that of ACL injury. The most common mode of injury is a direct injury over the front of the tibia ‘Dashboard injury’. In sports, it can be seen in front on tackle or collision or when falling with knee bent (hyperflexion).

Causes

PCL Injuries are often due to a blow to the knee while it’s bent. These injuries are especially common in:

• Football
• Baseball

Grades of PCL Tear

PCL tears are graded I to III by the severity of injury with III being the most severe.

These gradings are classified depending on the amount of backward tibial movement observed when the knee is bent at 90 degrees.

In extreme cases, the ligament may become avulsed (pulled off the bone completely).

• Grade I – Partial tears of the PCL.
• Grade II – Isolated, complete tear to the PCL.
• Grade III – Tear of the PCL with other associated ligament injuries

Symptoms

The most common symptoms of a PCL tear are:

• Pain with swelling.
• Deceased movement at knee joint
• A sensation of the knee “popping” or giving way.
• Tenderness along the joint line
• Walking discomfort

Diagnosis

Special Test (Posterior Drawer Test)

A proper examination may be difficult in the case of a swollen knee, but special tests like the “Posterior Drawer Test” can help clarify what’s wrong.
In this test, the doctor pushes the shin back while the knee is bent at 90 degrees.
If the Tibia gives more than 5 millimeters, the PCL is likely to be torn.

Radiological Investigation

X-rays: These are ordered to rule out avulsion fractures at the knee joint.

Magnetic Resonance Imaging (MRI): MRI is an effective tool for determining whether the PCL is torn or not, if so, then also helps in assessing the extent of the damage. It will also provide information on the other knee ligaments & the meniscus.

Treatment

Initial treatment of a PCL injury includes:

RICE

(Rest, Ice, Compression, Elevation).

• Bracing – Your doctor may recommend a brace to protect your knee from instability. To further protect your knee, you may be given crutches to keep you from putting weight on your leg.
• Physiotherapy – As the swelling goes down, a careful rehabilitation program is started. Specific exercises will restore function to your knee and strengthen the leg muscles that support it.

Surgical Management

Surgical reconstruction of the PCL is controversial and is usually only recommended for grade III PCL tears. Arthroscopic surgical reconstruction is a technically demanding procedure. Reconstruction can lead to improved knee stability and better functioning of the knee.

Surgical PCL reconstruction is difficult in part because of the position of the PCL in the knee. Generally, surgical PCL reconstruction is reserved for patients who have injured several major knee ligaments, or for those who cannot do their usual activities because of persistent knee instability.

Rehabilitation

In general, those who have sustained a PCL injury normally have good recovery rates, with most being able to return to sporting activities at the same level as before the injury. However, full recovery from cruciate ligament damage is highly dependent on the ability to adhere to a strict rehabilitation program.

Rehabilitation plays a crucial role in the post-operative management of PCL tear, similar to an ACL tear. It is focused on muscle strengthening and improving stability and must be initiated as early as possible. But progressing too quickly or too slowly can be detrimental to overall results from surgery, therefore it is important to be guided by a physiotherapist and doctor.