I’ve had my knee tested by two different orthopedic surgeons. There seems to be a difference of opinion about the extent of damage to the ligaments. One of the surgeons suggested doing an arthrometer test. She showed me the device they use to test the ligaments. Is there really any added benefit to this test?

Diagnosing ligamentous damage to the knee can be very difficult. There are many tests to choose from. Some are more sensitive than others. Applying them correctly is important. If the patient can’t relax the hamstrings (muscles behind the thigh and knee), then the test results aren’t always clear.

The KT-1000 and KT-2000 arthrometer devices are used to test specifically for insufficiency of the anterior cruciate ligament (ACL). They give objective, accurate, and reliable results.

The patient’s knee is bent to a 30-degree angle and placed on a special supportive wedge. The arthrometer is strapped to the calf. Proper positioning of the leg and foot is very important for this test.

A forward (anterior) force is applied on the tibia (lower leg bone). In fact, the test is conducted using three different amounts of force. If the tibia moves too far forward against the femur (thigh bone), the test is positive for an ACL tear.

The normal or uninvolved side can be tested first for comparison. Malposition of the arthrometer by as little as one centimeter can make a difference. However, it eliminates many of the other errors that can be made when using a hands-on testing method.