[17] Meniscal Tears Flashcards
What are the menisci?
C-shaped fibrocartilage found in the knee joint
What does the term meniscal tears refer to?
Damage to the menisci
Where are the menisci?
They rest on the tibial plateau
What are the main functions of the menisci?
- Shock-absorbers of the knee joint
- Increase articulating surface area
Which meniscus is more circular?
Medial
What is the medial meniscus attached to?
The medial collateral ligament
Is the lateral meniscus attached to the lateral collateral ligament?
No
What are the most common causes of meniscal tears?
- Trauma-related injury
- Degenerative disease
What does the mechanism usually involve in traumatic meniscal tears?
Typically a young patient who has twisted their knee whilst it is flexed and weight-bearing
What are the types of menisceal tears?
- Vertical
- Longitudinal
- Transverse (parrot-beak)
- Degenerative
What is the most common type of menisceal tears?
Longitudinal tear, often termed ‘bucket-handle’
What happens in a longitudinal menisceal tear?
The central tear becomes seperated from the lateral fragment
How do menisceal tears present?
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
When might the knee be locked in flexion after a mensiceal year?
In cases where the menisceal tear results in a free body within the knee, typically the bucket-handle type
What will be found on examination in menisceal tears?
- Joint line tenderness
- Significant joint effusion
- Limited knee flexion
What are the specific tests to identify a meniscal tear on examination?
- McMurray’s Test
- Apley’s Grind Test
Why are the specific tests to identify meniscal tears not often used?
Because they can prove very painful to the patient
What are the differential diagnoses of menisceal tears?
- Fracture
- Cruciate ligament tear
- Collateral ligament tear
- Osteochondritis dissecans
What investigations are done in suspected menisceal tears?
- Plain film radiographs
- MRI scan
Why are plain film radiographs often done in the initial assessment of a menisceal tear?
To exclude a fracture
What is involved in the immediate management of mensiceal tears?
Rest and elevation with compression and ice
What will happen with most small (<1cm) mensiceal tears?
They will initially swell, however the pain will subside over the next few days as the tears heals
When is arthroscopic surgery indicated in mensiceal tears?
For those with larger tears, or those remaining symptomatic
When can a menisceal tear often be sutured back together?
If it is in the outer third of the meniscus
Why can a meniscal tear often be sutured back together when it is in the outer 1/3 of the meniscus?
Because it has a rich vascular supply
How is a menisceal tear managed if the tear is in the inner third?
It is often trimmed
How is a menisceal tear managed if it is in the middle third?
It may either be repaired or trimmed
What are the risks of knee arthroscopy?
- DVT
- Damage to local structures
What local structures may be damaged in knee arthroplasty?
- Saphenous nerve and vein
- Peroneal nerve
- Popliteal vessels
What is a menisceal tear a risk factor for?
Developing osteoarthritis later in life
