Bone Disorders (OA/RA/OP) Flashcards
(41 cards)
what are the characteristics of a joint in osteoarthtitis?
thickened capsule, cyst formation and sclerosis in subchondral bone, shelving ‘fibrillated’ cartilage, osteophytic lymphing, synovial hypertrophy, altered bone contour
what cartilage is primarily affected by OA, and how so?
articular cartilage
causes increased swelling, colour change, cartilage fibrillation, cartilage erosion down to subchondral bone
what are the 3 types of cartilage?
hyaline (articular)
elastic (nose/ear)
fibrocartilage (meniscus/pubic ramus)
what 2 things is cartilage made up of?
cells (chrondocytes)
extracellular matrix (collagen/water)
describe the 3 layers of cartilage
superficial, middle and deep zone, all have different compositions of collagen and chondrocytes, calcified cartilage within
describe the function of the cartilage features
chondrocytes - synthesise and maintain ECM
ECM - collagen type 2 embedded in proteoglycan gel, protects chondrocytes from loading forces
what biological changes are seen in OA?
decreases in water content, proteoglycan synthesis, collagen cross linking and hyalauronic acid
trauma damage
what are the primary and secondary types of OA?
primary - degenerative
secondary - trauma, hip dysplasia, infection, diabetes
what may an x-ray find in OA?
LOSS
L - loss of joint space
O - osteophytes
S - subchondral sclerosis
S - subchondral cysts
what non-surgical treatments are administered for OA?
medications, physiotherapy, walking aids, joint injections
what are the surgical treatments administered for OA?
arthroscopy, cartilage transplantation, bone re-alignment, joint replacement
what are the principles of joint replacement surgery?
remove worn cartilage and replace with synthetic material
objective - pain relief, increase motion range, improve daily life activities
What is autoimmunity?
loss of immunological tolerance to self
describe the basics of RA
widespread joint pain, stiffness and swelling leading to joint destruction
what are some of the systemic symptoms of RA?
fevers, weight loss, extra-articular features (inflammation in other joints)
name the 6 phases of RA development
genetic risk factors
environmental risk factors
autoimmunity
symptoms
undifferenciated arthritis
RA
where are most genes causing RA found?
in adaptive immunity pathways (B-cell, T-cell, cytokines)
what environmental risk factor aggrevates the shared epitope (HLA-DRB1 allele)
smoking
explain the physiological changes occuring in the autoimmunity stage of RA development
autoantibodies present (rheumatoid factor and CCP)
increased cytokines and chemokines
altered cholestorol metabolism
explain the changes in the symptom phase of RA development causing the symptoms
monocytes/macrophages activated
and cytokine and chemokines release causing damage, meaning more self-antigens and epitope spread
local tissue environment takes over (osteoclasts)
inflammation becomes established
what is the standard treatment for RA?
DMARDs (disease-modifying anti-rheumatic drugs) e.g methatrexate
NSAIDs
corticosteroids
what are biologic agents?
drugs (e.g monoclonal antibodies) which have been developed rationally by targetting processes important in disease pathogenesis (e.g T-cells)
what are the differences in using biologic drugs compared to conventional drugs?
biologics differ in size, manufacturing complexity, and in the way they interact with cells and other proteins in the body
define OA
chronic degenerative change of damaged articular cartilage
