Dr. Jeff Abrams
Princeton, New Jersey

A physical exam is helpful in determining complete tears.

F. Alan Barber MD, FACS
Plano, Texas

There are several ways to determine if your ACL is torn. First, the history of your injury can be very suggestive of a torn ACL. Next, there are two special tests (Lachman and Pivot shift tests) that we perform. They are only positive with torn ACLs. If there is still a question about whether or not the ACL is torn, an MRI test can be obtained.

Dr. Don Johnson
Ottawa, Canada

It does not matter whether the ligament is partially or completely torn. If the knee is lax, which can be measured by clinical examination or with the KT-2000 arthrometer, the ACL is not functioning to protect the knee against pivotal motions. The MRI can determine if the ligament is completely torn, but can't differentiate the degree of laxity.

Dr. Hugh West
Salt Lake City, Utah

For the vast majority of patients, we can almost always tell that they have torn their ACL by examining the knee and testing it for looseness. When we show the patient how their knees compare to each other, the normal to the injured side, they can usually appreciate how the knee is looser after the injury. We use a KT-2000 in order be able to compare how loose their knee is before and after surgery, and also after rehabilitation. We almost never need an MRI in order to tell if the ACL is torn; consequently we don't order them very often.