Anterior cruciate ligament (ACL) function tests

• anterior drawer test
  • the patient is lying supine with the hip flexed to 45 degrees and the knee flexed to 90 degrees
  • examiner sits on the patients foot and place the hands behind the proximal tibia and thumbs on the tibial plateau
  • anterior force is applied to the proximal tibia with the index fingers palpating the hamstring tendons to ensure that they are relaxed
  • increased anterior tibial displacement compared with the opposite side is indicative of an ACL tear (1)
  • Click here for video of anterior drawer test
    
    
• Lachman test
  • patient is lying in supine position with the knees held between full extension and 15 degrees of flexion
  • with the use of one hand stabilize the distal femur (just above the knee) and apply firm pressure to the posterior aspect of the proximal tibia with the other hand (in an attempt to sublux the tibia anteriorly)
  • anterior translation of the tibia with a 'soft' endpoint is considered to be a positive test indicating ACL rupture (1,2)
  • Click here for video of Lachman test

Reference:

• 1. Malanga GA et al. Physical examination of the knee: a review of the original test description and scientific validity of common orthopedic tests. Arch Phys Med Rehabil. 2003;84(4):592-603
• 2. Calmbach WL, Hutchens M. Evaluation of patients presenting with knee pain: Part I. History, physical examination, radiographs, and laboratory tests. Am Fam Physician. 2003;68(5):907-12.