Knee ACL & PCL Evidence: confirmed

Lachman Test Special Test

Orthopedic Physical Examination & Clinical Assessment Guide

Lachman Test Orthopedic Special Test

What is it used for?

  • Assessing the integrity of the Anterior Cruciate Ligament (ACL), specifically the posterolateral bundle.
  • Considered the “Gold Standard” for acute ACL injury.

How to Perform

  • Position: Patient lies supine. Knee flexed to 20-30°.
  • Action: Stabilize the distal femur with one hand. Grasp the proximal tibia with the other.
  • Force: Apply a quick anterior translation force to the tibia.

Interpretation of Results

  • Positive Test: Excessive anterior translation (>3mm) compared to the uninjured side, or a “soft/mushy” end-feel (lack of a sudden stop).

Diagnostic Accuracy

  • Sensitivity: 85%
  • Specificity: 94%

References

  • Magee, D. J. (2021). Orthopedic Physical Assessment.
  • Miller, M. D. (2020). Miller's Review of Orthopaedics.