23- Histopathology of joint diseases Flashcards
What are the 3 main types of joints
- Fibrous
- Cartilaginous
- Synovial joints
Where are fibrous joints found?
Between the bones of the skull
Where are cartilaginous joints found?
Between ribs and sternum allowing certain movements
Where are synovial joints found?
Between 2 bones allowing movement
What are some features of synovial joints?
- covered in cartilage
- capsule of dense fibrous tissue, holds synovial fluid in place
- contains synovial fluid and synovium
What is synovium?
Synovial membrane which lines the inner surface of the joint excluding the cartilage
What are some features of articular cartilage?
Very hard, smooth made up of collagen, no blood supply, receives nutrition from synovial fluid
What happens to articular cartilage when damaged?
It cannot repair itself, it will eventually degenerate
What are 3 types of diseases of synovial joints
- trauma
- inflammatory
- non-inflammatory
E.G of trauma?
hemarthrosis
What are 2 types of infection?
- crystal induced
- primary inflammatory
Example of non-inflammatory?
osteoarthritis
Can you have a tumour in a joint?
No
Who has greater genetic susceptibility of rheumatoid disease?
Women, twins, HLA antigen
What are some immunological markers present in rheumatoid disease?
- Autoantibodies
- Cellular immunity
- cytokines
What are some autoantibodies found in rheumatoid disease?
Rheumatoid factor, citrulline
What are some cellular immunity found in rheumatoid disease?
T cells (CD8+)
What are some cytokines found in rheumatoid disease?
TNFs (tumour necrosis factor alpha),
IL1 (interleukin 1)
What are prostaglandins and leukotrienes classed as?
Arachadonic acid metabolites (small molecules that control pain)
What happens to synovium when inflammed?
normally synovium is flat. when inflamed has small finger-like projections known as pannus, this pannus grows over and destroys articular cartilage, degrading the cartilage from below the marrow surface
What is another name for inflamed synovium?
Pannus
What does destruction of bone lead to?
erosions and osteoporosis
What does the destruction of cartilage, capsule, ligamentsleads to?
Joint instability, subluxation
What is subluxation?
Partial dislocation of joint, the inflammatory process destroys the capsule as well as surrounding muscle making it unstable
What is tenosynovium?
inflammation of cartilage which surrounds tendon, leading to joint pain, swelling and stiffness
What is chondrolysis
Cartilage destruction
what is chondrolysis driven by?
IL1, TNFa
How can erosions around small joints affect the cervical spine
can cause spinal instability
How can spinal instability be life threatening?
- interferes with the blood supply to the brain
- impingement on the upper cervical spinal cord
How can rheumatoid disease affect the oral cavity?
Reduced manual dexterity
Drugs can cause oral ulcers
What must you give patients with Rheumatoid disease?
Antibiotics
What is ankylosing spondylitis?
Autoimmune conditions attacking soft tissues around the vertebrae leading to fusion of the spine
-inflammation followed by modification of tendons and ligaments insertions these calcify and bones ankylose leading to a fused spine
How does ankylosing spondylitis affect the oral cavity?
Restricts mouth opening
What is osteoarthritis?
Progressive loss of articular cartilage and excessive production of bone can form cysts in bone
Where does osteoarthritis start?
starts focally, propogates towards collagen until collagen is lost
