POSTERIOR CRUCIATE LIGAMENT

POSTERIOR CRUCIATE LIGAMENT

The posterior cruciate ligament is located in the back of the knee. It is one of several ligaments that connect the femur (thighbone) to the tibia (shinbone). The posterior cruciate ligament keeps the tibia from moving backwards too far.

An injury to the posterior cruciate ligament requires a powerful force. A common cause of injury is a bent knee hitting a dashboard in a car accident or a football player falling on a knee that is bent.

The anterior and posterior cruciate ligaments form an "X" in the center of the knee.

While a posterior cruciate ligament injury generally causes less pain, disability and knee instability than does an ACL tear, it can still sideline you for several weeks or months.

DESCRIPTION

Injuries to the posterior cruciate ligament are not as common as other knee ligament injuries. In fact, they are often subtle and more difficult to evaluate than other ligament injuries in the knee.

Many times a posterior cruciate ligament injury occurs along with injuries to other structures in the knee such as cartilage, other ligaments, and bone.
A complete tear of the posterior cruciate ligament, back view.

Injured ligaments are considered "sprains" and are graded on a severity scale.

Grade 1 Sprains. The ligament is mildly damaged in a Grade 1 Sprain. It has been slightly stretched, but is still able to help keep the knee joint stable.

Grade 2 Sprains. A Grade 2 Sprain stretches the ligament to the point where it becomes loose. This is often referred to as a partial tear of the ligament.

Grade 3 Sprains. This type of sprain is most commonly referred to as a complete tear of the ligament. The ligament has been split into two pieces, and the knee joint is unstable.

Posterior cruciate ligament tears tend to be partial tears with the potential to heal on their own.
 People who have injured just their posterior cruciate ligaments are usually able to return to sports without knee stability problems.

CAUSES

An injury to the posterior cruciate ligament can happen many ways. It typically requires a powerful force.

• A direct blow to the front of the knee (such as a bent knee hitting a dashboard in a car crash, or a fall onto a bent knee in sports)
• Pulling or stretching the ligament (such as in a twisting or hyper-extension injury.
• Simple misstep

Sports are a common cause of PCL injury. These injuries are especially common in:

• Football
• Soccer
• Baseball
• Skiing

SYMPTOMS

The typical symptoms of a posterior cruciate ligament injury are:

• Pain with swelling that occurs steadily and quickly after the injury
• Swelling that makes the knee stiff and may cause a limp
• Difficulty walking
• The knee feels unstable, like it may "give out"
• Swelling (mild to severe)
• Knee pain
• Wobbly sensation in the knee
• Trouble walking or bearing weight on the knee

Over time, a PCL tear can lead to osteoarthritis in the knee.

TREATMENT

 RICE. When you are first injured, the RICE method - rest, ice, gentle compression and elevation — can help speed your recovery.

Immobilization. Your doctor may recommend a brace to prevent your knee from moving. To further protect your knee, you may be given crutches to keep you from putting weight on your leg.

Physical therapy. 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. Strengthening the muscles in the front of your thigh (quadriceps muscles) has been shown to be a key factor in a successful recovery.

Surgical Treatment

PCL problems can be acute or chronic. Acute PCL problems are due to a sudden injury. Chronic PCL problems involve an injury that develops over time.

DIAGNOSIS

X-rays and MRIs are also helpful in clarifying the diagnosis and detecting any other structures of the knee that may be injured. It is common to find other ligament injuries or cartilage damage when a PCL tear is found.

PHYSIOTHERAPY AND REHABLITATION MANAGEMENT

The goal of the rehabilitation for individuals undergoing a conservative program is to control the initial inflammatory phase and regain ROM with muscle function as quickly as possible.
PCL TEARS

Apply the rest, ice, compression, and elevation (RICE) method several times a day, in addition to any other modalities incorporated by the physical therapist to control pain and swelling (eg, electrical stimulation, cold whirlpool).

Patients with grade I and grade II injuries can bear weight as tolerated immediately, though some may require axillary crutches initially. Axillary crutches and a long leg brace are recommended for grade III injuries and with other associated ligamentous laxity (ie, posterolateral corner injury) or intra-articular damage.

  FUNCTIONAL ELECTRICAL STIMULATION (FES) may be used to stimulate the quadriceps muscle, but it is probably necessary only if the quadriceps muscle is shut down secondary to pain.

• The physical therapist should instruct the patient in exercises for                                                                                                 
• QUADRICEPS AND HIP STRENGTHENING
• QUADRICEPS SETS
• STRAIGHT LEG RAISES

•  HIP ABDUCTION/ADDUCTION

( multi-angle quadriceps isometrics). At this time, all open kinetic chain (OKC) hamstring exercises should be avoided since they impart posterior tibial translation at the knee.

Initial Exercises

These initial exercises should generally be performed 3 times daily:                     

HEEL-SLIDES OR KNEE BEND TO STRAIGHT                                                                                                                                              
                          
Begin this exercise by lying on your back . Bend and straighten your knee as far as you can go without pain and provided you feel no more than a mild to moderate stretch. Repeat 10 - 20 times.

STATIC QUADRICEPS CONTRACTION
                                                                                Begin this exercise in the position demonstrated  Tighten the muscle at the front of your thigh (quadriceps) by pushing your knee down into a towel. Put your fingers on your inner quadriceps (VMO) to feel the muscle tighten during contraction. Hold for 5 seconds and repeat 10 times as hard as possible without increasing your symptoms.

RISK FACTORS

Men are more likely than are women to injure their posterior cruciate ligament. Participation in sports such as football and soccer also may increase your risk.

COMPLICATIONS

In many cases, other structures within the knee — including other ligaments or cartilage — also are damaged when you experience a posterior cruciate ligament injury. Depending on how many of these structures were damaged, you may experience some long-term knee pain and instability. You may also be at higher risk of eventually developing arthritis in your affected knee.