Lachman test

Anterior cruciate ligament (ACL) testing

Assessment of ACL injured knees, pre and post-ACL injuries, including KT-100 arthrometry

About the anterior cruciate ligament

If your ACL is torn, your knee may become unstable and lose its full range of movement. You can tear your ACL if your lower leg extends forwards too much. It can also be torn if your knee and lower leg are twisted. This injury is commonly obtained during physically active sports.

Need to know

  • What happens during a Lachman's assessment test? icon plus

    Your consultant will test your knee's range of movement. To do this they will flex your knee to a moderate angle whilst you are lying face upwards.

    They will place one hand behind your shinbone (tibia) and the other will grasp your thigh. Your shinbone is then pulled forward to assess the range of movement of your shinbone in comparison to your thighbone (femur). A normal ACL should have a firm endpoint where the knee can move no further, whilst a damaged ACL won't have a firm endpoint.

    A medical tool called a KT-1000 is used to determine the size of movement in millimetres.
  • How to prepare for the assessment icon plus

    Your consultant will tell you how best to prepare for your test. You should wear loose fitting trousers that can easily be rolled up, or shorts, so the assessment can be carried out directly on the knee.
  • After the assessment icon plus

    There are no side effects or recovery time associated with this assessment. You'll be able to return to your normal daily routine immediately following the test. Your consultant will provide feedback on your results and advise your next steps. 

Our knee consultants

We're proud to work with leading orthopaedic consultant specialising in knee problems and injuries, and whose skills are matched by their integrity and compassion.

Our locations

From complex knee surgery to diagnostic tests and procedures, we provide exceptional orthopaedic care across our network of hospitals, outpatient centres and specialist clinics.

Request a knee appointment

We're happy to help you make an appointment with one of our experienced knee consultants. We can also make imaging and outpatient physiotherapy appointments for you.

Call us today

020 7079 4344
This content is intended for general information only and does not replace the need for personal advice from a qualified health professional.
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