rheumatology and orthopaedics

Question 1

define osteoarthritis

Answer 1

chronic slowly progressive disorder due to failure of articular cartilage that typically affecting joints of the hand (especially those involved in pinch grip), spine and weight-bearing joints (hips and knees)

Question 2

what age group does osteoarthritis usually affect

Answer 2

elderly (wear-and-tear)

Question 3

joints affected in osteoarthritis not affected in rheumatoid arthritis

Answer 3

distal interphalangeal joints

Question 4

joint feel in osteoarthritis vs rheumatoid arthritis

Answer 4

in osteoarthritis, joints feel bony and hard; in rheumatoid arthritis, joints feel spongy and soft

Question 5

general locations of joints affected in osteoarthritis

Answer 5

hand, spine, weight-bearing joints of lower limbs

Question 6

joints affected in osteoarthritis: hand

Answer 6

distal interphalangeal joints, proximal interphalangeal joints, first carpometacarpal joint

Question 7

joints affected in osteoarthritis: weight-bearing joints of lower limbs

Answer 7

knees, hips, first metatarsophalangeal joint

Question 8

what are osteophytes

Answer 8

bony projections (‘spur’) associated with degeneration of cartilage at joints

Question 9

what are osteophytes at the distal interphalangeal joints called

Answer 9

Heberden’s nodes

Question 10

what are osteophytes at the proximal interphalangeal joints called

Answer 10

Bouchard’s nodes

Question 11

6 associations of joints in osteoarthritis

Answer 11

pain, crepitus, instability, enlargement, stiffness and immobility (‘gelling’), limitation of motion

Question 12

when is joint pain caused by osteoarthritis better/worse

Answer 12

worse with activity, better with rest

Question 13

what is joint crepitus in osteoarthritis

Answer 13

creaking, cracking grinding sound on moving affected joint

Question 14

what causes joint enlargement in osteoarthritis

Answer 14

osteophytes

Question 15

how long does joint stiffness after immobility (‘gelling’) in osteoarthritis take to go away vs rheumatoid arthritis

Answer 15

much faster

Question 16

in osteoarthritis, what is joint instability caused by

Answer 16

atrophy of muscles around joint

Question 17

what joint movement is the first to be affected in osteoarthritis

Answer 17

internal rotation of hip

Question 18

4 radiographic features of osteoarthritis

Answer 18

joint space narrowing (lack of articular cartilage), subchondral bony sclerosis (appear much whiter), osteophytes, subchondral cysts (appear circular)

Question 19

rheumatoid vs osteoarthritis: joint space narrowing

Answer 19

both

Question 20

rheumatoid vs osteoarthritis: subchondral sclerosis

Answer 20

rheumatoid: no vs osteoarthritis: yes

Question 21

rheumatoid vs osteoarthritis: osteophytes

Answer 21

rheumatoid: no vs osteoarthritis: yes

Question 22

rheumatoid vs osteoarthritis: osteopenia

Answer 22

rheumatoid: yes (juxta-articular osteopenia) vs osteoarthritis: no

Question 23

rheumatoid vs osteoarthritis: bony erosions

Answer 23

rheumatoid: yes (where synovium in contact with bone) vs osteoarthritis: no

Question 24

normal articular cartilage structure and purpose

Answer 24

normally smooth cartilage layer to distribute weight, with synovial fluid in joint capsule and synovial membrane around it

Question 25

osteoarthritic articular cartilage structure

Answer 25

undergoes fragmentation and atrophy, with some fragments entering synovial fluid which are visible in x-ray

Question 26

why does defective and irreversible articular cartilage and damage to underlying bone occur in osteoarthritis

Answer 26

excessive loading on joints and/or abnormal joint components

Question 27

osteoarthritis general pathophysiology

Answer 27

genetic predisposition -> abnormal stress or abnormal cartilage -> chondrocyte apoptosis -> loss of proteoglycans and collagen fibril damage

Question 28

causes of abnormal stress in osteoarthritis

Answer 28

obesity, manual job, trauma to joints which haven't been set correctly

Question 29

causes of abnormal cartilage in osteoarthritis

Answer 29

ageing, inflammation, metabolic changes

Question 30

3 contents of synovial joint

Answer 30

synovium, synovial fluid, articular cartilage

Question 31

what is the main collagen type in synovium, and what cells make it up

Answer 31

type 1 collagen, with synovium consisting of synoviocytes

Question 32

what is synovial fluid

Answer 32

hyaluronic acid-rich viscous fluid

Question 33

what is collagen type and main proteoglycan of articular cartilage

Answer 33

type II collagen, with main proteoglycan being aggrecan

Question 34

property of synovial joint that allows robust strength from compression, that is lost in osteoarthritis

Answer 34

property to retain water (due to glycosaminoglycans in proteoglycans, with main proteoglycan in articular cartilage being aggrecan)

Question 35

what causes joint pain in osteoarthritis

Answer 35

bony spurs rubbing against skin, not collagen loss

Question 36

in articular cartilage, what are monomers arranged into

Answer 36

supramolecular aggregates consisting of central hyaluronic acid filament and non-covalently linked aggrecan

Question 37

what are glycosaminoglycans

Answer 37

repeating polymers of disaccharides

Question 38

3 cartilage changes in osteoarthritis

Answer 38

reduced proteoglycan, reduced collagen, chondrocyte changes e.g. apoptosis

Question 39

2 bone changes in denuded sub-articular bone in osteoarthritis

Answer 39

oroliferation of superficial osteoblasts causing production of sclerotic bone (subchrondral sclerosis), focal stress on sclerotic bone resulting in focal superficial necrosis

Question 40

purpose of osteophytes

Answer 40

unsure as to whether is it a primary feature of osteoarthritis or attempt of body to repair

Question 41

pain vs x-ray in osteoarthritis

Answer 41

poor correlation between what appears to be happening and pain felt (pain subjective)

Question 42

7 management strategies of osteoarthritis

Answer 42

education, physical therapy (physiotherapy, hydrotherapy; prevent muscles around joint undergoing atrophy and causing joint instability), occupational therapy, weight loss where appropriate, exercise, analgesia, joint replacement

Question 43

3 analgesic options to treat osteoarthritis

Answer 43

paracetamol, NSAIDs, intra-articular corticosteroid injection (no role of DMARDs)

Question 44

in osteoarthritis, when would you administer an intra-articular corticosteroid injection

Answer 44

last attempt, as they only last a couple of weeks and repetition damages cartilage further

Question 45

describe the benign prognosis of osteoarthritis

Answer 45

there is an initial painful phase (approx. 5 years), before subsiding (bony changes don’t go away, so pain could be bone remodelling)

Question 46

2 therapeutic approaches for osteoarthritis not approved in UK

Answer 46

glucosamine and chondroitin sulphate (placebo effect of replacing structures of joint, but unsure if even reaches joint), intra-articular injections of hyaluronic acid into knee (lubricant, but no evidence)