Lachman Test


- See:
      - Anterior Cruciate Ligament
      - Anterolateral Rotatory Instability
      - Clunk Test
      - Losee Test
      - Pivot shift

- Discussion:
    - this is a variant of the anterior drawer test, in which the examination is carried out w/ the knee in 15 deg of flexion, and external rotation (relaxes IT band);
    - for a right knee, the examiner's right hand grips the inner aspect of the calf and the left hand grasps outer aspect of the distal thigh;
    - attempt to quantify the displacement in mm (comparing this displacement to the normal side);
    - end point should be graded as hard or soft;
           - end point is said to be hard when the ACL abruptly halts the forward motion of the tibia on the femur;
           - end point is soft when there is no ACL & restraints are more elastic secondary stabilizers;

              

- Definition of Severity:
    - clinical exam:
          - mild: 0 to 5 mm laxity (greater than the uninvolved side)
          - moderate: 6 to 10 mm laxity (greater than the uninvolved side)
          - severe: 11 to 15 mm laxity (greater than the uninvolved side)
                  - when exam reveals such a large amount of translation always consider concomitant MCL tear / meniscal tear;
    - KT-1000:
          - greater than 11 mm of anterior translation of the injured side or greater than 3 mm of side to side difference (delta lachman) indicates ACL tear;
          - following ACL reconstruction, laxity should be less than 3 mm compared to opposite side


Lachman test evaluated. Quantification of a clinical observation.

Injury to the anterior cruciate ligament producing the pivot-shift sign.

Long-term functional results in patients with anterolateral rotatory instability treated by iliotibial band transfer.

Arthrometric evaluation of knees that have torn anterior cruciate ligament

What Really Happens During the Lachman Test? A Dynamic MRI Analysis of Tibiofemoral Motion.

Relationship Between the Pivot Shift and Lachman Tests: A Cadaver Study

Similarities and Differences of Diagnostic Manual Tests for Anterior Cruciate Ligament Insufficiency. A Global Survey and Kinematics Assessment




Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, May 1, 2012 4:45 pm