Lachman Test

 Lachman Test

What is Lachman Test?

  • Lachman Test is used to Assess the integrity of the anterior cruciate ligament (ACL)

How it's Performed?

  • The patient is positioned supine with their injured knee flexed to 20 to 30 degrees while also slightly externally rotating the injured leg to relax the iliotibial band.
  • The examiner then uses one hand to stabilize the distal femur while using the other hand to grasp the proximal tibia.
  • Next, an anterior force is applied to the proximal tibia in an attempt to sublux the tibia forward while keeping the femur stabilized

What does a positive Lachman Test mean?

  • The Lachman Test is considered positive if there is excessive anterior translation of the proximal tibia greater than the uninjured side and also a lack of a firm endpoint.
  • Endpoints are graded from “hard” to “soft,” and have been nominally classified as :
    • A (firm, hard endpoint)
    • B (absent, soft endpoint).

Sensitivity & Specificity

  • Sensitivity: 87 %
  • Specificity: 93 %


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