Pivot Shift Test: Checking for Anterolateral Knee Instability

The Pivot Shift Test is a specific clinical maneuver used to assess Anterolateral Rotary Instability (ALRI) of the knee. It is commonly used to confirm an ACL tear and replicates the sensation of the knee "giving way."

1. Purpose

The primary purpose of the Pivot Shift Test is to **test for** Anterolateral Rotary Instability (ALRI) of the knee. It is highly specific for detecting an Anterior Cruciate Ligament (ACL) tear, often indicating functional instability or the knee's tendency to "give way."

2. How to Perform

1. The patient is positioned in supine with the leg fully extended and relaxed.
2. The examiner lifts the patient's leg by grasping the heel/ankle with one hand and internally rotates the tibia.
3. The examiner places the other hand on the lateral aspect of the proximal tibia (just below the knee) to apply a valgus force.
4. While maintaining internal rotation and valgus stress, the examiner slowly flexes the knee from full extension.

3. Positive & Negative Sign

Positive Sign (Test is POSITIVE):
A positive test (indicating ALRI/ACL tear) is:

• A palpable or audible "clunk" or shift typically felt between 20 and 40 degrees of flexion.
• This happens because the tibia (which was subluxed anteriorly in extension) suddenly reduces (shifts back) into position due to the pull of the Iliotibial (IT) band.

Negative Sign (Test is NEGATIVE):
A negative test is when the knee flexes smoothly without any clunking or shifting sensation.