Physiology of cartilage Flashcards
(21 cards)
what re the 3 main types of cartilage?
Articular/hyaline
Fibrocartilage
Elastic
What are the 2 divisions of articular cartilage and where are they found?
Skeletal - articular, costal, growth plate
Extra-skeletal - trachea, larynx, nose
Where is elastic cartilage found?
epiglottis
Ear
where is fibrocartilage found?
Meniscus
Intervertebral disc
What is the function of articular cartilage?
Provide a smooth lubricated surface for articulation
Facilitate load transmission and low friction movement
What are the 2 main components of cartilage? what proportions do they exist in?
Cells (5%)
ECM (95%)
What is part of the cellular component of cartilage? what is their function?
chondrocytes - synthesise and maintain the ECM
What are the components of the extracellular component of cartilage?
Water (70%)
Organic (30%) - mainly type 2 collagen, proteoglycans, hyaluronic acid chains with links contains chondroitin and keratin sulphate
What are the layers of articular cartilage on bone?
Articular cartilage
Subchondral bone
Cancellous bone
What is necessary for cartilage to heal?
Penetration of subchondral bone for access to blood supply
What does cartilage homeostasis depend on?
Balance between synthesis and degradation of cartilage
What molecules are needed for degradation of cartilage ?
MMPs: collagenase aggrecanase gelatinases stromelysins
What molecules are needed for synthesis of cartilage ?
collagen
proteoglycans
proteins
name methods used for diagnosis of cartilage injuries
X-ray
MRI
Arthroscopy
Describe the non-surgical management of cartilage injuries
Physiotherapy
Paracetamol
NSAIDs
Alternative medication: glucosamine and chondroitin sulphate (no evidence but patients claim they work)
Viscosupplementation (no evidence to show it works)
Steroid injection
wHy are steroid injections only a short term solution
they ultimately kill chondrocytes
What’d does viscosuplementation involve?
Injecting synthetic synovial fluid into the joint
List the surgical management of cartilage injuries
Arthroscopy: to perform micro fracturing
Cartilage transplant
Joint replacement
Describe the use of arthroscopy as a treatment
TO perform micro-fracturing
Used in small cartilage defects in younger patients to break the subchondral bone to allow cartilage healing.
Describe the use of cartilage transplantation as a treatment
Cartilage taken from non-weight bearing portion, performed in people under the age of 30 with small defects
Describe the use of joint replacement surgery as a treatment. What objective does it achieve?
cartilage removed and replaced with synthetic material
Relieves pain and increases range of motion
