Lemaire Jolt Test For ACL Tears

Lemaire Jolt Test is a specialized clinical examination maneuver used to assess anterolateral rotatory instability of the knee, most commonly associated with anterior cruciate ligament (ACL) deficiency and injury to the anterolateral complex. Although less frequently performed than pivot-shift variants, it remains an important test for advanced orthopedic and sports medicine evaluation.

Purpose of the Test

The Lemaire Jolt Test evaluates:

• Anterolateral rotatory instability
• Functional integrity of the ACL
• Contribution of the anterolateral structures, including the iliotibial band and lateral capsule

A positive Lemaire Jolt Test indicates pathological anterior translation and rotation of the tibia relative to the femur.

How to Perform the Lemaire Jolt Test for ACL Tears?

Patient Position

• The patient is placed in a side-lying (lateral decubitus) position
• The test leg is uppermost
• The knee starts in full extension
• Patient relaxation is essential for accurate interpretation

Examiner Position and Hand Placement

1. Distal hand (foot control):
   • The examiner grasps the patient’s foot
   • The tibia is medially rotated while the knee is in extension
2. Proximal hand (lateral stabilization):
   • The dorsum of the examiner’s other hand applies light pressure against:
     • The biceps femoris tendon
     • The head of the fibula

This hand acts as a stabilizing and palpating contact point to detect abnormal tibial movement.

Lemaire Jolt Test Maneuver

• While maintaining medial rotation of the tibia, the examiner passively flexes and extends the knee
• The movement is smooth and controlled
• Special attention is paid during early knee flexion

Positive Lemaire Jolt Test

• At approximately 15°–20° of knee flexion, a sudden “jolt” or shift of the tibia is felt
• This represents anterior displacement of the lateral tibial plateau
• A palpable or visible jolt indicates a positive Lemaire Jolt Test

Clinical Interpretation

A positive test suggests:

• Anterolateral rotatory instability
• ACL insufficiency, often chronic
• Possible involvement of the anterolateral ligament or lateral capsular structures

The test is particularly useful when combined with other rotational instability tests, such as:

• Pivot Shift Test
• Slocum Test
• Lelli (Lever Sign) Test

Common Errors and Pitfalls

• Inadequate patient relaxation
• Excessive force during rotation
• Poor control of tibial rotation
• Misinterpreting soft tissue movement as a true jolt

Teaching Tips for Students

• Always compare with the contralateral (uninjured) knee
• Perform the test slowly to appreciate subtle instability
• Think of the jolt as a dynamic subluxation event, similar in mechanism to the pivot shift

Clinical Relevance

Lemaire Jolt Test is particularly relevant in:

• Chronic ACL injuries
• High-demand athletes
• Preoperative evaluation before ACL reconstruction
• Consideration of anterolateral augmentation procedures

Comparison of Rotational Instability Tests of the Knee

References & More

1. Liorzou G. Knee Ligaments: Clinical Examination. Berlin: Springer-Verlag; 1991.
2. Orthopedic Physical Assessment by David J. Magee, 7th Edition.