Menisci Flashcards
What is the predominant collagen in Menisci
Type 1
What meniscal cells are found in the inner zone
Fibrochondrocytes
What meniscal cells are found in the outer zone
Fibroblasts
3 ligaments associated with Menisci
Mensico-tibial ligament
Transverse menisco-meniscal ligament
Medial & Lateral Collateral Ligament
What is the importance of the MCL?
MCL provides extra anchorage of the medial meniscus to the tibia
This makes it less mobile and therefore more prone to injury compared to the lateral
What is the red zone?
The outer 30% of the meniscus that is well vascularised
What is the white zone?
The inner 70% of the meniscus that receives nutrients via diffusion from synovial fluid
Composition of Menisci
60-80% Water
15-25% Collagen (Predominantly type 1)
1-2% Proteoglycans
Collagen organisation in Superficial layer
Thin fibrils that have random mesh-like arrangement
This provides a smooth outer surface for the joint
Collagen organisation in Peripheral 2/3
Circumferential arrangement
Radial fibres
Thicker fibres
Collagen organisation in Inner 1/3
Random arrangement of collagen and Proteoglycans
Functions of Menisci (6)
Decrease contact stress in 2 ways:
o Provide greater contact are between tibia and femur
o Due to its wedge shape and circumferential fibres,
compressive forces can be turned into circumferential
tensile stresses - hoop stress
o Lubrication
o Assist proprioception
o Providing nutrition to articular cartilage
o Increase joint stability
o Shock absorber
What is the most common knee injury
Meniscal tear
Which meniscus has the smaller radius of curvature (more curved)
Lateral
Symptoms of meniscal tear (4)
Pain
Clicking
Locking (knee cannot fully extend)
Swelling
