Osteoarthritis

Question 1

Aetiology of OA

Answer 1

Mechanical “wear + tear”
localised loss of cartilage
remodelling of adjacent bone
associated inflammation

Question 2

List 5 common RFs for OA

Answer 2

AGE
F > M
FH
Previous trauma of joint
Hypermobility of joint
Obesity

Question 3

Typical joints affected in OA

Answer 3

Large weight-bearing joints (knee, hip)
Carpometacarpal joint
DIP, PIP joints

Question 4

3 features of classic OA history

Answer 4

Pain following use, improves with rest
Unilateral Sx
No systemic upset

Question 5

X-ray features of OA

Answer 5

Loss of joint space (affects distal joints more)
Osteophytes forming at joint margins
Subchondral sclerosis
Subchondral cysts

(LOSS)

Question 6

3 risk factors for hip OA

Answer 6

F > M (2:1)
Obesity
DDH

Question 7

Give 3 red flag features that suggest an alternate diagnosis to hip OA

Answer 7

Rest pain
Night pain
Morning stiffness > 2h

Question 8

What tool is commonly used to assess severity of hip OA?

Answer 8

Oxford Hip Score

Question 9

Describe investigations for hip OA

Answer 9

If features are typical: clinical dx
Otherwise: plain x-rays are first-line

Question 10

Describe management of hip OA

Answer 10

Analgesia PO
Intra-articular injections (short-term benefit)
Total hip replacement remains the definitive Tx

Question 11

List 4 peri-operative complications of total hip replacement

Answer 11

VTE
Intraoperative fracture
Nerve injury
Surgical site infection

Question 12

What reduces risk of VTE post total hip replacement?

Answer 12

LMWH for 4w following op

Question 13

List 4 post-op complications of total hip replacement

Answer 13

Leg length discrepancy
Posterior dislocation
Aseptic loosening
Prosthetic joint infection

Question 14

Describe posterior dislocation of a total hip replacement

Answer 14

May occur during extremes of hip flexion
Presents acutely with a ‘clunk’, pain + inability to weight bear
OE: internal rotation + shortening of the affected leg

Question 15

Post-hip replacement, what advice is given to reduce risk of dislocation?

Answer 15

Avoid flexing hip > 90 degrees
Avoid low chairs
Do not cross your legs
Sleep on back for the first 6w

Question 16

What is the most common reason for revision of a total hip replacement?

Answer 16

Aseptic loosening

Question 17

2 Risk factors for hand OA

Answer 17

F > M (3:1)
Occupation e.g. cotton workers + farmers

Question 18

How is hand OA most commonly detected?

Answer 18

Radiologic signs are more common than Sx

Question 19

What does hand OA increased risk of?

Answer 19

Future hip + knee OA

Question 20

Which joints of the hand are most commonly affected in OA?

Answer 20

1st Carpometacarpal (CMCs) +
Distal interphalangeal (DIPJs) >
Proximal interphalangeal (PIPJs)

Question 21

Describe symptoms of hand OA

Answer 21

Intermittent joint ache. Provoked by movement + relieved by rest
Stiffness: worse after long periods inactivity (waking up), lasts a few mins

Question 22

List signs of hand OA

Answer 22

Painless nodes
Squaring of the thumbs
Wasting of thenar muscles at base of thumb

Question 23

What are the painless nodes that develop in hand OA called? What causes these?

Answer 23

Bouchard’s nodes: PIPJ
Heberden’s nodes: DIPJ
Result of osteophyte formation

Question 24

What causes squaring of the thumbs in hand OA?

Answer 24

Subluxation of CMC (partial dislocation), formation of osteophytes, + remodelling of the bones.
Results in fixed adduction of thumb.

Question 25

Describe initial management of OA

Answer 25

All should be offered help with weight loss, given advice about local muscle strengthening exercises + general aerobic fitness
TOP NSAIDs first-line (particualrly beneficial for OA of knee or hand)

Question 26

Describe second line management of OA

Answer 26

NSAIDs PO + PPI
Walking aids (knee/ hip OA)
Intra-articular steroid injection if standard Tx ineffective (short term relief 2-10w)
Consider referral for joint replacement

Question 27

Describe use of paracetamol or weak opioids in OA

Answer 27

NOT recommended unless
only used infrequently for short-term pain relief
AND
all other pharmacological Tx are CI, not tolerated or ineffective