Lecture 20: Joint and joint tissues Flashcards
phases of fracture healing
phase 1 of fracture healing
-bleeding-> haemotoma
-rupture of the periosteum + bleeding are important for initiating repair. Deliver & stimulate mesenchymal stem cells + fibroblasts. Initiate macrophages to come and clean up debri + activate osteoclasts to break down some of the bone
+ activation of cytokines. Want some inflammation. Cytokines stimulate osteogenic cells to differentiate into osteoblasts + mesenchymal cells into chondrocytes
+growth factors delivered in blood
phase 2
~ 5 weeks after
haemotoma callus forming 1st-> cartilagenous callus
(if the bones are not close together-> form an intermediate structure(callus)- cartilage template )
Stabilizes the break.
~similar to endochondral ossification
phase 3
~3 months
bony callus formation
-osteoblasts laying down osteoid-> becomes mineralised but not organized into lamellar bone and osteon structures yet
phase 4
~1.5 years?
-bony lump remodeled
-bone is nicely structured and organised into lamellar bone
fibrous joints
-no synovial cavity
-articulating bones held together by fibrous CT
types:
-suture
-syndesmosis
-interosseous membrane
cartilaginous joints
-no synovial cavity
-articulating bones united by hyaline cartilage or fibrocartilage
types:
-synchondrosis
-symphysis
synovial joints
-synovial cavity
-articular cartilage
-articular (joint) capsule
-may contain accessory ligaments, articular discs, and bursae
types:
-plane
-hinge
-pivot
-condyloid
-saddle
-ball-and-socket
suture(joint): description, functional classification, and example
syndesmosis: description, functional classification, and example
interosseous membrane: : description, functional classification, and example
synchondrosis joint : description, functional classification, and example
symphysis joint : description, functional classification, and example
plane joint : description, functional classification, and example
hinge joint : description, functional classification, and example
pivot joint : description, functional classification, and example
condyloid joint: description, functional classification, and example
saddle joint : description, functional classification, and example
ball-and-socket joint : description, functional classification, and example
2 layers of the joint capsule
-fibrous outer capsule( thick)
tough outer layer of collagen fibers
resists overextension of a synovial joint
perforated by nerves and BV
-inner synovial membrane(thin)
lines joint capsule
secretes synovial fluid
how does cartilage get nutrients?
the closest blood supply to cartilage in the joint is the synovial membrane-> cartilage gets nutrients through diffusion from synovial fluid
osteoarthritis: description, causes
Osteoarthritis is a disease affecting the articular cartilage of synovial joints.
With repetitive use of the joints over the years, the water content of the cartilage increases, and the
protein components such as collagen start to break down. This irritates and inflames the cartilage,
causing joint pain and swelling. Eventually, cartilage begins to degenerate by flaking or forming tiny
crevasses. In advanced cases, there is a total loss of the cartilage cushion between the bones of the
joints. Loss of cartilage cushion causes friction between the bones, leading to pain and limitation of
joint mobility.
Chronic inflammation!
Primary OA – no known cause
* Risks: age, obesity, genetics, mechanics and
others
* Over 60% of adults over 60 have OA in NZ
Secondary OA
* occupation, injury
*damage to ACL-> OA risk
gout: description, causes
Gout is one of the most common forms of arthritis, and it is often said to be the most painful.
- Inflammatory arthritis caused by deposition of monosodium
urate (MSU) crystals within the joint. - Most common form of inflammatory arthritis affecting
men in New Zealand
It occurs as an acute attack, often coming on overnight. Within 12-24 hours there is severe pain and swelling in
the affected joint. The skin over the joint may also become red and shiny. Gout affects more men than
women, in women it occurs after menopause. Gout usually affects only one or two joints at a time
– most often the big toe; feet, ankles, knees, wrists, and fingers can be also affected.
Without treatment, the attack subsides in a week or so. If gout is not treated, attacks become more frequent and more severe and can lead to joint damage and disability.
Gout is caused by high level of uric acid in the blood. The main factors that increase uric acid in the
body:
* genetic (i.e. it runs in the family)
* being overweight
* high alcohol intake, especially beer
* high intake of foods that produce a lot of uric acid e.g. some seafood
* some drugs for the treatment of high blood pressure
* long standing kidney disease
* high intake of fructose rich drinks
what are other abnormalities in the OA joint?
management 7 treatment of knee OA
- NSAIDs/ pain relief
- Weight management
- Cortisone injections in the joint
- Exercise
- Cartilage repair techniques e.g.
- Microfracture
- Mosaicplasty
- Autologous Matrix Induced Chondrogenesis (AMIC)
- Arthroplasty (hemi or full)
management of gout
- Manage diet and lifestyle – low purine diet
- Avoidance of alcohol and fructose sugary drinks
- Acute: Anti-inflammatory treatment (colchicine)
- Long term: urate lowering drugs such as allopurinol.
Other joint tissues:
- Menisci – fibrocartilage pads for knee
- Common to tear with sports
- Fat pad – padding for protection
- Bursa – can become inflammed - overuse.
- Tendons and ligaments
Collagen structures with limited blood supply
Stabilise joints
Very strong in tension
Poor healing capacity
