Osteoarthritis

Question 1

What is osteoarthritis?

Answer 1

a disease of synovial joints in which the articular cartilage becomes split, fissured and softened and gradually resorbs, sometimes down to underlying bone
subchondral bone becomes thickened and hard and there is formation of osteophytes

Question 2

What are the secondary causes of osteoarthritis?

Answer 2

fractures (especially intra-articular injuries) 
joint inflammation 
inflammatory joint disease 
congenital abnormalities 
joint instability 
cartilage damage 
obesity

Question 3

Which joints are most commonly affected?

Answer 3

weight bearing joints

hip and knee

Question 4

What is the prevalence of hip osteoarthritis? (in learning objectives)

Answer 4

12% of >65 year olds

Question 5

What is the prevalence of knee osteoarthritis? (in LOs)

Answer 5

35% of adults >75 years

Question 6

What are the main presenting features of osteoarthritis?

Answer 6

pain
stiffness
swelling
deformity

Question 7

Describe the pain in osteoarthritis?

Answer 7

slowly increasing in severity as the joint stiffens
morning pain may indicate inflammatory component
pain is usually exacerbated by exercise but joint often feels stiff after rest

Question 8

What is a good way to assess severity of pain?

Answer 8

Ask - Does it disturb sleep?

Question 9

How do patients describe the stiffness in osteoarthritis?

Answer 9

not usually a major cause of complaint - may make putting on socks difficult

Question 10

Why is there swelling seen in osteoarthritis?

Answer 10

due to over-production or under-absorption of synovial fluid
bony swelling may result from osteophyte formation

Question 11

What causes deformity in osteoarthritis?

Answer 11

severe destruction of the bone esp at the knee and ankle
deformity also results from soft tissue changes
can affect gait, function, and nearby joints

Question 12

What is seen on inspection in osteoarthritis?

Answer 12

fixed deformities
swelling due to moderate synovial thickening and bony enlargement of the joint due to osteophytes and occasional effusions during acute episodes

Question 13

What is seen on palpation in osteoarthritis?

Answer 13

tenderness around the joint

swelling

Question 14

What is seen on movement in osteoarthritis?

Answer 14

restriction in movements
muscle spasm and pain when pushing beyond the limit
crepitus on movement
abnormalities of the goat

Question 15

What are the risk factors for osteoarthritis?

Answer 15

age 
obesity 
genetics 
gender (females)
hypermobility 
trauma 
congenital joint dysplasia 
joint incongruity leads to earlier OA
occupation

Question 16

What are the causes of joint incongruity that leads to earlier onset of OA in the effected joint?

Answer 16

congenital dislocation of the hip
slipped femoral head epiphyses
perthes disease

Question 17

What are the occupations that increase the risk of OA?

Answer 17

miners (hip, knee and shoulder)
cotton workers (hand)
farmers (hip)

Question 18

What are the causes of secondary causes of OA?

Answer 18

pre-existing joint damage (RA, gout, seronegative spondyloarthropathy, septic arthritis, pages disease, avascular necrosis)

metabolic disease (acromegaly, chonedrocalcinosis, hereditary hameochromatosis)

systemic disease (haemophilia due to hamearthrosis, haemoglobinopathies, neuropathies)

Question 19

What is the difference between primary and secondary OA?

Answer 19

primary OA - no identifiable causes

secondary OA - identifiable cause

Question 20

What are the different types of primary OA?

Answer 20

localised OA - nodal and erosive

erosive OA

Question 21

What is nodal OA?

Answer 21

joints of the hand are affected one at a time over several years
DIP joints are affected more than PIP joints

Question 22

How does nodal OA present and progress?

Answer 22

onset may be painful with swelling and impairment of hand function, often around female menopause 
inflammatory phases settles leaving painless bony swellings, stiffness and deformity 
function is not usually affected

Question 23

Where are Heberden’s nodes?

Answer 23

nodes around DIP

Question 24

What are Bouchard’s nodes?

Answer 24

nodes around the PIP

Question 25

What is erosive OA?

Answer 25

also called inflammatory arthritis
rare
DIPs and PIPs are inflammed and equally affected
may develop into RA and may not be true subset of OA

Question 26

What is primary generalised OA?

Answer 26

associated with immune complex formation and may have an autoimmune cause

female predominance
strong familial tendency

Question 27

What joints are affected in primary generalised OA?

Answer 27

knee, first metacarpophalangeal joint, hip and intervertebral joints are affected

onset is often sudden and severe

Question 28

What is an example of secondary OA?

Answer 28

crystal associated OA

Question 29

What is crystal associated OA?

chonedrocalcinosis

Answer 29

calcium pyrophosphate deposition in the cartilage
increases in frequency with age
usually asymptomatic
knees and wrist are commonly affected, then shoulders, elbows, ankles and hips

Question 30

What is seen on X-ray in crystal associated OA?

Answer 30

patchy linear calcification on x-ray with osteophytes and cyst formation

Question 31

How does the rare, more severe form of crystal associated OA present?

Answer 31

rapidly destructive arthritis
found in elderly women
deposition of calcium apatite in a bloody joint effusion
affects the shoulders, hips and knees
poor outlook that requires early surgical replacement