PCL And Multiple Ligament Injuries

PCL And Multiple Ligament Injuries

The strength of the knee comes from four ligaments – one on inside of the knee, one on outside, and two in the middle. The one on inside is called MCL (Medial Collateral Ligament), the one on outside is called LCL (Lateral Collateral Ligament), and the two in the middle of the knee are called cruciate ligaments. Usually, it is only one or sometimes two ligaments which get torn. Rarely, more than two ligaments, and sometimes all the four ligaments are torn.

PCL injury:

PCL (posterior cruciate ligament) is a major ligament of the knee. It is situated in the middle of the knee in its back part. It is responsible for not allowing the knee to move backward. It may be injured if the knee is hit from the front, for example in a head-on crash, where something from front hits the knee. Injury to this ligament is not as dramatic, and is missed often. In the past, it was thought that PCL injury can be left as it is, and it does not cause much problem. But, it is now understood that PCL is an important ligament, injury to this ligament needs to be treated by surgical reconstruction in many cases. It is a tricky operation as a part of the operation is done at the back of the knee, an area where important nerves and blood vessels of the leg lie. This operation is done by key hole (arthroscopic) surgery.

PCL Reconstruction

What is the PCL?

PCL (posterior cruciate ligament) is a major ligament of the knee. It is situated in the middle of the knee in its posterior (back) part. It is responsible for not allowing the knee to move backward.

How is it injured?

It may be injured if the knee is hit from the front, for example in a head on crash where something from front hits the knee. Injury to this ligament is not as dramatic, and is missed often.

Does it need surgery if torn?

In the past, it was thought that PCL injury can be left as it is, and it does not cause much problem. But, it is now understood that PCL is an important ligament, injury to this ligament needs to be treated by surgical reconstruction in most cases.

How is it done?

This surgery is a keyhole (arthroscopic) surgery. The same hamstring tendons are harvested with an inch incision in front of the knee and fashioned into the new ligaments. This is introduced via an arthroscopic tunneling technique that involves a small 1 cm cut on the back of the knee too. It is fixed with specialized devices on the leg and thigh bones.

What are the results of PCL surgery?

They are excellent with a less than 5% chance of the graft not being accepted by the body. This however requires the right rehabilitation techniques.

What are the complications?

Apart from the standard possible complications associated with ACL surgery there is a possible chance of injury to the vessels at the back of the knee in these operations. However they rarely occur if done in the right hands.

What is the post operative rehabilitation?

Its almost the same as an ACL reconstruction.

The only difference is a support is kept under the back of the leg and the patient needs to wear a long knee brace for 6 weeks while walking.

Flexion and extension exrecises are done in prone position

The restrictions are slightly more than after an ACL reconstruction and near normal walking occurs at about 6 weeks.

Running and jogging at 4-5 months and sports after 6-9 months

MCL injury:

MCL (medial collateral ligament) is often injured in a knee bending inward, or when hit from outside. This is one of the easier ligament, as it heals up in most cases by simple rest in brace. When associated with injury to other ligaments such as ACL, or in obese patients, tear of this ligament may also need reconstruction.

Do we always need to operate on it?

This is a rather friendly ligament and heal up in about half the cases when it is torn off from the thigh bone or the middle of its substance. This healing takes about 6 weeks and requires some element of immobilization like a brace.

When do we need to operate?

Surgery is required when the knee continues to open up from the inside after 6 -8 weeks, or if the injury is from the attachment to the leg bone. Sometimes when associated with injuries to multiple ligaments of the knee, early repair may be required.

What kind of operation is done?

There are two types

  1. Repair: This is done when the ligament has just come out of its attachment at either end. Then the original ligament is just repaired back to its place.
  2. Reconstruction: This is done when the ligament is completely torn and lacks its original structure. The hamstring tendons (semitendinosus/gracilis) is used to make a new ligament and fixed with specilaised devices.
What is the post op rehabilitation?

Depending if done in isolation or with another concomitant ligament reconstruction.

If in isolation, the patient is kept on a long knee brace for 6 weeks and is allowed to bend the knee out of the brace keeping the knee in a cross legged position. Walking is permitted with the brace using a walker/crutches. However for 6 weeks the patient needs to wear the brace while walking.

If present with other ligament reconstruction the rehabilitation depends on which other ligament is injured.

MCL injury

MCL (medial collateral ligament) is often injured in a knee bending inward, or when hit from outside. This is one of the easier ligament, as it heals up in most cases by simple rest in brace. When associated with injury to other ligaments such as ACL, or in obese patients, tear of this ligament may also need reconstruction.

Multiple ligament injury to the knee

This severe damage occurs in serious accidents. The knee often dislocates, or becomes severely unstable. It becomes impossible to even move the leg in one piece. Any attempt at putting load on the leg makes the knee 'give way'. In early stages, there is bluish discolouration of the knee due to the blood seeping out under the skin. In severe injuries, there may occur damage to the nerves and vessels of the leg, and may make this injury limb threatening. Most young and active patients would need surgery for these injuries. These operations are hightly specialized, and only few surgeons experienced in this field can perform them well. Post surgery physiotherapy is an important part of overall treatment.