[17] Meniscal Tears

Question 1

What are the menisci?

Answer 1

C-shaped fibrocartilage found in the knee joint

Question 2

What does the term meniscal tears refer to?

Answer 2

Damage to the menisci

Question 3

Where are the menisci?

Answer 3

They rest on the tibial plateau

Question 4

What are the main functions of the menisci?

Answer 4

• Shock-absorbers of the knee joint
• Increase articulating surface area

Question 5

Which meniscus is more circular?

Answer 5

Medial

Question 6

What is the medial meniscus attached to?

Answer 6

The medial collateral ligament

Question 7

Is the lateral meniscus attached to the lateral collateral ligament?

Answer 7

No

Question 8

What are the most common causes of meniscal tears?

Answer 8

• Trauma-related injury
• Degenerative disease

Question 9

What does the mechanism usually involve in traumatic meniscal tears?

Answer 9

Typically a young patient who has twisted their knee whilst it is flexed and weight-bearing

Question 10

What are the types of menisceal tears?

Answer 10

• Vertical
• Longitudinal
• Transverse (parrot-beak)
• Degenerative

Question 11

What is the most common type of menisceal tears?

Answer 11

Longitudinal tear, often termed ‘bucket-handle’

Question 12

What happens in a longitudinal menisceal tear?

Answer 12

The central tear becomes seperated from the lateral fragment

Question 13

How do menisceal tears present?

Answer 13

Patients report a ‘tearing’ sensation in their knee, associated with an intense sudden-onset pain. The knee then swells slowly over a period of 6-12 hours.

Knee may be locked in flexion, and unable to extend

Question 14

When might the knee be locked in flexion after a mensiceal year?

Answer 14

In cases where the menisceal tear results in a free body within the knee, typically the bucket-handle type

Question 15

What will be found on examination in menisceal tears?

Answer 15

• Joint line tenderness
• Significant joint effusion
• Limited knee flexion

Question 16

What are the specific tests to identify a meniscal tear on examination?

Answer 16

• McMurray’s Test
• Apley’s Grind Test

Question 17

Why are the specific tests to identify meniscal tears not often used?

Answer 17

Because they can prove very painful to the patient

Question 18

What are the differential diagnoses of menisceal tears?

Answer 18

• Fracture
• Cruciate ligament tear
• Collateral ligament tear
• Osteochondritis dissecans

Question 19

What investigations are done in suspected menisceal tears?

Answer 19

• Plain film radiographs
• MRI scan

Question 20

Why are plain film radiographs often done in the initial assessment of a menisceal tear?

Answer 20

To exclude a fracture

Question 21

What is involved in the immediate management of mensiceal tears?

Answer 21

Rest and elevation with compression and ice

Question 22

What will happen with most small (<1cm) mensiceal tears?

Answer 22

They will initially swell, however the pain will subside over the next few days as the tears heals

Question 23

When is arthroscopic surgery indicated in mensiceal tears?

Answer 23

For those with larger tears, or those remaining symptomatic

Question 24

When can a menisceal tear often be sutured back together?

Answer 24

If it is in the outer third of the meniscus

Question 25

Why can a meniscal tear often be sutured back together when it is in the outer 1/3 of the meniscus?

Answer 25

Because it has a rich vascular supply

Question 26

How is a menisceal tear managed if the tear is in the inner third?

Answer 26

It is often trimmed

Question 27

How is a menisceal tear managed if it is in the middle third?

Answer 27

It may either be repaired or trimmed

Question 28

What are the risks of knee arthroscopy?

Answer 28

• DVT
• Damage to local structures

Question 29

What local structures may be damaged in knee arthroplasty?

Answer 29

• Saphenous nerve and vein
• Peroneal nerve
• Popliteal vessels

Question 30

What is a menisceal tear a risk factor for?

Answer 30

Developing osteoarthritis later in life