Dr. Jonathan Mulford, Orthopaedic Surgeon, NSW Australia Total Knee Replacement, NSW Australia
Sports Knee Ligament Reconstruction, NSW Australia
Knee Arthroscopy, NSW Australia

Meniscus

Function (What do they do?)

  • Congruency – Make the joint smooth
  • Shock Absorption – Protect the knee from "wear and tear"
  • Stability
  • Proprioception – Makes you aware of your leg
  • Distribute load and contact area
    • Medial carries 50% of the load in extension (when knee is straight)
    • Lateral carries 70% load in extension
    • If medial meniscus removed
      • 50% contact area decreased and
      • 100% increase contact stress
    • If lateral meniscus removed
      • 50% contact area decreased and
      • 250% increase contact stress

Assessment of the The Meniscus

The meniscus can be assessed with a MRI scan or an arthroscopy. MRI scan has the benefit of not requiring surgery. It is useful if the diagnosis from history and examination is not clear cut or other injuries are being sought. It can also assess the cartilage on the end of the femur (thigh bone) and tibia (shin bone). Arthroscopic evaluation and treatment of meniscal pathology may be required if the patient is symptomatic.

MRI Scan of Meniscus

Normal appearance of a meniscus

  • In cross section the meniscus is triangular and fill the space between the femur (thigh bone) and tibia (shin Bone)
MRI appearance of a meniscal tear (Bucket Handle tear)   The meniscus (blue) has torn and displaced into the middle of the joint
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At the back of the knee there is a missing part to the meniscus (red triangle) it has displaced and moved into the middle of the knee. 

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Arthroscopic View of Knee

Normal Meniscus and Cartilage on the Femur and Tibia with Arthroscopy

Viscosupplementation for Knee Arthritis, NSW Australia Meniscus, NSW Australia

Arthroscopic View of a Meniscal Tear

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Meniscal Tears

Men more than women 4:1
Up to 1/3 associated with ACL rupture

Type of tears – Verticle (bucket), Oblique, Horizontal, Radial Partial Medial Menisectomy

The majority of meniscal tears are not repairable and the treatment is to remove any unstable meniscal components that are causing pain.

As the torn meniscus is not normal it loses its normal function and acts more like a “rock in the shoe”.

If there is no cartilage damage (the lining of the end of the femur and tibia) then the patients with medial meniscal tears will usually do very well.

In the future there is a risk of getting arthritis – The amount of time for this to occur and how bad it affects a given individual is not possible to predict.

Those patients with lateral meniscal tears have a more guarded prognosis. Often initially they can do well. The lateral tibia is convex and thus the meniscus is important to provide a cup for the femur to fit into.

Arthritis and Meniscal tears

When there is associated arthritis some relief can be provided with arthroscopy, especially if there are mechanical symptoms.

It does not solve the problem of arthritis however and thus some discomfort may continue. Arthroscopy can be a simple low risk procedure to consider prior to larger procedures such as osteotomy and joint replacement.

Indications to repair

  • Patient Factors – Active, Age <45, Compliant
  • Extra-meniscal factors – Stable knee, No deformity, No arthritis
  • Meniscal Factors – Complete vertical tear 1-4 cm, peripheral 20%, tear displaces >3mm

Post Repair

  • Partial weight bear crutches, hinge brace 4 weeks
  • No flexion greater than 90 degrees until after 6 weeks
  • No pivot 6 months
Knee Replacement Surgery, NSW Australia
Sydney Orthopaedic Surgeon, NSW Australia

I am a orthopaedic surgeon that specialises in all aspects of Hip and Knee surgery...

Meet Dr. Jonathan Mulford
Trauma Surgery, NSW Australia
Dr Mulford was awarded a Diploma in Clinical Trials from the University of London in 2008.
Clinical Research
Location Maps Acute Knee Injury Clinic
Revision Knee Replacement, NSW Australia  
Wrist Arthroscopy, NSW Australia
Tamar Valley Orthopaedics
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