Osteoarthritis

Question 1

arthritic conditions

Answer 1

inflammatory- characterised by inflammation of joints and other tissues, degenerative, OA- multifunctional disease

Question 2

causes of serious joint pain

Answer 2

malignancy or infection ,inflammatory arthritis, metastatic disease, septic arthritis

Question 3

OA risk factors

Answer 3

genetics, joint mobility, age- increased age, BMI- obesity, muscle, gender- female, race, pain perception, joint morphology

Question 4

hip OA

Answer 4

loss of joint space, degenerative joint disease that may be caused by progressive damage to articular cartilage, and other structures- 11% of people affected

Question 5

hip OA- changes

Answer 5

osteophyte formation- extra bony growth§, subchondral sclerosis- shows up on MRI, subchondral cysts, deformity

Question 6

knee OA

Answer 6

OA affects 8.5 million in UK, 4th largest cause of disability, 4.7 million sought out medical treatment for painful knee OA, projected that it will double due to increasing age population and life choices

Question 7

what is cartilage composed of

Answer 7

extracellular matrix that is produce by chondrocytes. it consists of 80% of water and collagen fibres, proteoglycans, glycosaminoglycans, and some non collagenous proteins. no blood vessels/ nerves/ lymphatics- receive nutrients via diffusion of molecules through extracellular matrix

Question 8

different zones in articular cartilage

Answer 8

zone 1/2/3 separated from zone 4 that contains calcified cartilage, which lies superficial to subchondral zone, there is a tide mark that highlights separation- indication of where cartilage starts to calcify

Question 9

articular cartilage- collagen fibres

Answer 9

the collagen fibres within articular hyaline cartilage showing strength under tension and the ability to withstand compression. type 2 collagen is most prominent in articular cartilage (90%)- composed of compact topological collagen molecules= strength

Question 10

proteoglycans

Answer 10

proteins that are responsible for majority of water content in tissue- provide strength, consist of linear protein, attached to proteoglycan aggregate= elastic properties and mechanical strength

Question 11

normal cartilage homeostasis in joint

Answer 11

maintained by delicate balance between synthesis and degradation of extracellular matrix by chondrocytes. MMP- key in degradation of type 2 collagen- activity is increased by IL-1 and TNF, is inhibited by- TIMP

Question 12

articular cartilage in OA

Answer 12

increase in water content and progressive breakdown in collagen network due to breakdown of type 2 collagen. IL-1 stimulation of chondrocytes causes these cells to produce plethora- activates which increases amount of plasmin- leads to breakdown of cartilage by activation of matrix MPS and collagenase in MM3, breakdown of structure

Question 13

the normal subchondral bone- boundary

Answer 13

boundary between calcified cartilage and noncalcified is tide mark- the region for CC to bone marrow in subchondral bone, primary cells are osteoblasts, which produce bone matrix, and osteoclasts that are responsible for bone reabsorption and breakdown of matrix=remodeling

Question 14

tidemark in OA knee

Answer 14

the tide mark is breached and the articular cartilage extends through the tide mark into the subchondral plate and blood vessels from SC bone- leads to vascularization of cartilage- this is accompanied by the growth of nerves- leads to signals of pain being sent- these structures are now painful tissues

Question 15

where does OA pain come from

Answer 15

ligaments, muscle, joint capsule, AC and synovial osteophytes

Question 16

bony changes in OA

Answer 16

progressive cartilage degeneration- joint space narrowing, increased bone absorbing sclerosis, osteophytes- bony outgrowth- attempt to stabilize joint

Question 17

the kellgren- Lawrence OA classification- grade- 0, I, II

Answer 17

0- normal, I- doubtful narrowing of joint space, possible osteophyte development, II- define osteophytes, absent or questionable narrowing of joint space

Question 18

the kellgren- Lawrence OA classification- grade- III, IV

Answer 18

III- moderate osteophytes, definite narrowing, some sclerosis, and possible joint deformity
IV- large osteophytes, marked narrowing, severe sclerosis and joint deformity

Question 19

progression of BML

Answer 19

associated with pain in patients with OA, highlighted in progressive OA on MRI. they are a result of synovial fluid penetrating through defects in articular cartilage and entering the subchondral bone leading to microfracture and oedema

Question 20

BMLs and pain

Answer 20

associated with pain, cartilage nutrition, bone nutrition, meniscal pathology. can have structural changes with disability, OA split into- pain, disability and structural changes

Question 21

clinical symptoms of knee OA

Answer 21

pain on most days of the last month, inactivity stiffness lasting no longer than 30 mins- if longer= inflammatory arthritis crepitus on moving joint, bony tenderness, limitations of movement, no palpable warmth, bony enlargement with osteophytic lipping,

Question 22

when are symptoms of OA greatest

Answer 22

individuals greater than 5- years of age

Question 23

summary of OA

Answer 23

OA is well conserved active/ reparative process, most OA is clinically occult, subchondral bone remodelling, vascularization of the NCC and CC, multiple risk factors, attribute risk varies between sites, risk factors may be intact, biomechanical risk factors appear dominant