Crystal Arthropathies

Question 1

Gout crystals:

Answer 1

Monosodium urate

Negatively-birefringent needle-shaped crystals on polarised light microscopy

Question 2

Pseudogout crystals:

Answer 2

Calcium pyrophosphate

Positively-birefringent rhomboid-shaped crystals on polarised light microscopy

Question 3

Hyperuricaemia is caused by:

Answer 3

1. Increased urate production
2. Reduced urate excretion

Question 4

Increased urate production is caused by:

Answer 4

Inherited enzyme defects
Myeloproliferative/Lymphoproliferative disorders
Psoriasis
Alcohol (beer, spirits)
High dietary purine intake (red meat, seafood, corn syrup)

Question 5

Reduced urate excretion is caused by:

Answer 5

Chronic renal impairment
Volume depletion e.g. heart failure
Hypothyroidism
Diuretics
Cytotoxic drugs e.g. ciclosporin

Question 6

Acute gout features:

Answer 6

Monoarthropathy of 1st MTP/ankle/knee
Settles in 10 days without treatment and 3 days with treatment
Abrupt onset
May have normal uric acid during acute attack

Question 7

Chronic tophaceous gout features:

Answer 7

Chronic joint inflammation
Often diuretic associated
High serum uric acid
Tophi
May get acute attacks

Question 8

Gout investigations:

Answer 8

Polarised light microscopy (essential to exclude septic arthritis ASAP)

Serum uric acid may be raised
Raised inflammatory markers
Renal impairment (may be cause or effect)

Question 9

Gout treatment:

Answer 9

Acute:
NSAIDs
Colchicine
Steroids

Start preventative treatment 1 week after acute attack:
1. Xanthise oxidase inhibitor (Allopurinol, febuxostat)
2. Uricosuric drugs (Sulfinpyrazone, probenecid, benzbromarone)

Question 10

Indications for prophylactic therapy in gout:

Answer 10

1) One or more attacks of gout in a year in spite of lifestyle modification.
2) Presence of gouty tophi or signs of chronic gouty arthritis.
3) Uric acid calculi.
4)Chronic renal impairment.
5)Heart failure where unable to stop diuretics.
6)Chemotherapy patients who develop gout.

Question 11

Pseudogout age group most affected and why?

Answer 11

Older = increased chance

because chondrocalcinosis increases with age

+ related to osteoarthritis

Question 12

Where does pseudogout affect?

Answer 12

Fibrocartilage - knees, wrists, ankles

Question 13

Pseudogout treatment:

Answer 13

NSAIDS
Colchicine
Steroids
Rehydration.

NO PREVENTATIVE TREATMENT AVAILABLE.

Question 14

Hydroxyapatite crystal deposition leads to…

Answer 14

‘Milwaukee shoulder’ - rare

Acute and rapid deterioration/destruction. Females, 50-60 years old.

Question 15

Pain not localised, more generalised soft tissue pain. Diagnosis?

Answer 15

Fibromyalgia

Question 16

Causes of shoulder soft tissue pain:

Answer 16

Commonest area for soft tissue pain

-Adhesive Capsulitis
-Rotator cuff tendinosis
-Calcific tendonitis
-Impingement
-Partial rotator cuff tears
-Full rotator cuff tears

Question 17

Causes of elbow soft tissue pain:

Answer 17

Medial and lateral epicondylitis
Cubital tunnel syndrome

Question 18

Causes of wrist soft tissue pain:

Answer 18

De-Quervain’s tenosynovitis

Carpal tunnel syndrome

Question 19

Causes of pelvis soft tissue pain:

Answer 19

Trochanteric bursitis

Stress enthesopathies

Question 20

Cause of foot soft tissue pain:

Answer 20

Plantar Fasciitis

Question 21

Joint hypermobility syndrome - signs and symptoms:

Answer 21

Joint pains esp. after exercise/physical work.

Joint stiffness.

Foot and ankle pain.

Neck and backache.

Frequent sprains and dislocations.

Thin stretchy skin.