Corpus3D

Knee

Lachman test

What you examine
Rupture of the anterior cruciate ligament, assessed at around 20 to 30 degrees of knee flexion.
Procedure
Knee at 20 to 30 degrees of flexion. Fix the femur with one hand and pull the tibia forward with the other.
Positive when
Increased anterior translation with a soft or absent end feel, compared with the other knee.
What the test is worth
The best clinical test for the ACL: sensitivity around 0.85 and specificity around 0.94.
Caution
The end feel counts for more than the amount of translation; a large but firmly ending translation can simply be laxity.
Joint
Knee joint
Body region
Knee

Structures involved