ACL Tears

What are ACL Tears?

The Anterior Cruciate Ligament, or ACL, is one of the major ligaments of the knee that is in the middle of the knee and runs from the femur (thigh bone) to the tibia (shin bone). It prevents the tibia from sliding out in front of the femur. Together with posterior cruciate ligament (PCL) it provides rotational stability to the knee.

What are the causes of ACL tear?

An ACL injury is a sports related injury that occur when the knee is forcefully twisted or hyperextended. An ACL tear usually occurs with an abrupt directional change with the foot fixed on the ground or when the deceleration force crosses the knee. Changing direction rapidly, stopping suddenly, slowing down while running, landing from a jump incorrectly, and direct contact or collision, such as a football tackle can also cause injury to the ACL.

What are the symptoms of ACL tear?

When you injure your ACL, you might hear a "popping" sound and you may feel as though the knee has given out. Within the first two hours after injury, your knee will swell and you may have a buckling sensation in the knee during twisting movements.

How is an ACL tear diagnosed?

Diagnosis of an ACL tear is made from your acute injury history, subsequent symptoms, performing an experienced physical examination of the knee, and performing other diagnostic tests such as MRI scans. An ACL tear diagnosis should always be made before surgery and an arthroscopy is NOT necessary to make the diagnosis.

What are the treatment options for ACL tear?

Treatment options include both non-surgical and surgical methods.

In young people non-surgical options are only recommended if the ACL tear is partial. This type of injury is extremely rare. Most tear are complete. Non-surgical treatment consists of rest, ice, compression, and elevation (RICE protocol); all assist in controlling pain and swelling. Physical therapy may be recommended to improve knee motion and strength. A knee brace may be needed to help immobilize your knee.

Young athletes involved in pivoting sports will most likely require surgery to safely return to sports. The usual surgery for an ACL tear is an ACL reconstruction (ACLR) which tightens your knee and restores its stability. Surgery to reconstruct an ACL is done with an arthroscope using small incisions. Your doctor will replace the torn ligament with a tissue graft that can be obtained from your knee (patellar tendon) or hamstring muscle. Following ACL reconstruction, a rehabilitation program is started to help you to resume a wider range of activities.

What is best: Patella Tendon (PT ACLR) or Hamstring (HS ACLR)?

Similar to the evaluation of Joint Replacement success using National Joint Registries, the success of different types of ACLR has been recorded in 2 European and 1 American ACLR Registry all containing 10,000 cases or more of ACLR and using Revision (operation redone as first ACLR failed) as an indicator of the success of the first operation.

This Registry data in recent years has clearly demonstrated that the failure rate of HS ACLR to be up to 4x higher than PT ACLR. This difference in results strongly favouring PT ACLR is due to a number of factors.

The main one is that PT ACLR is a considerably more difficult operation than HS ACLR so that if the surgeon does not do a lot of ACL reconstructive surgery he/she will always chose the easier operation. They will then tell you that they acknowledge the published results but their results are better! I was recently called to help an experienced HS ACLR surgeon who was doing a PT ACLR Revision. It took 4 hours!

You are therefore better off having a HS ACLR than a PT ACLR if the surgeon is a "low volume ACL surgeon"

Another very worrying piece of data is that the Keiser Permanente ACLR Registry in the USA shows that the infection rate of HS ACLR is 8x higher than PT ACLR.