Lachmans Test

Last updated 20.05.13

 

Index

 

Definition

-  Test of integrity of anterior cruciate ligament

 

Features

-  Part of examination of knee joint

-  Variant of Anterior Draw Test

 

Indications

-  Knee injury with suspected ACL tear

 

Procedure

-  Patient supine

-  Flexion of knee to 15o with slight external rotation

-  Examiner faces patients head from lower part of bed

-  Grasp medial aspect of calf with one hand distal to knee joint

-  Other hand grasps lateral aspect of lower thigh

-  Lateral hand pushes posteriorly whilst medial hand pulls anteriorly

-  Attempt to quantify amount of displacement

-  Compare to opposite side

 

 

Results

-  End point

-  Soft = ACL ruptured & tibia slowed by elastic ligaments: ACL injury

-  Hard = ACL halts forward motion of tibia on femur

-  Displacement compared to other side

-  Mild 0-5mm

-  Moderate 6-10mm

-  Severe 11-15mm

-   Consider medial collateral ligament injury & meniscal tear

 

 

 

References

 

Wheeless Textbook of Orthopaedics, www.wheelessonline.com/ortho/lachman_test

Pic: www.orthopaedicsone.com/download/attachments/4554895/lachman+1.JPG