ORTHO 137 Monoarthritis and Gout

Question 1

Define Gout

Answer 1

An inflammatory response to monosodium urate monohydrate crystals in the joint

Question 2

How does gout typically present?

Answer 2

As an acute monoarthritis: joint inflammation

Question 3

What joint is gout most common in?

Answer 3

the metatarsophalangeal joint - big toe

Question 4

What are tophi?

Answer 4

Solid lumps of uric acid that may develop in those with chronic gout

Question 5

What are some of the causes of gout?

Answer 5

Purine rich diet e.g. beer, cider (alcohol excess0

Diuretics and renal impairment

Question 6

How would you investigate gout?

Answer 6

Joint fluid: crystals
Blood: check for metabolic syndrome (blood sugar, fasting lipids, LFT’s); urea, urate and creatinine
Urinalysis: blood and protein

Question 7

How would you manage and treat gout?

Answer 7

Lifestyle changes
Pain relief
Correct hyperuricaemia

Question 8

What pain relief would you give in gout?

Answer 8

NSAID’s
Colchicine (NSAID but without GI SE’s)
Steroids: oral or intraarticular

Question 9

How would you correct the hyperuricaemia in gout?

Answer 9

Xanthine oxidase inhibitors e.g. allopurinol & febuxostat

Uricosurics: increase secretion of uric acid

Question 10

What is Septic Arthritis?

Answer 10

Invasion of a joint by a pathogenic organisms causing joint inflammation

Question 11

What are differential diagnoses for a monoarthritis?

Answer 11

Septic arthritis
Crystal Arthritis
Trauma

Question 12

What are the normal physiological roles of calcium?

Answer 12

Formation of calcified tissues
Normal activity of nerve and muscle
NT release, hormonal and glandular secretions
Excitation/contraction coupling
Integrity and permeability of cell membranes
Cell adhesion
Blood clotting

Question 13

What 3 organs tightly regulate blood calcium?

Answer 13

Gut, kidenys and bone

Question 14

What 3 hormones contro blood calcium?

Answer 14

PTH, Calcitonin and Vitamin D3

Question 15

Where is PTH released from?

Answer 15

Chief cells in the paraythyroid glands

Question 16

What does PTH stimulate?

Answer 16

Bone resorption
Renal tubular reabsorption of Calcium
1-alpha hydroxylation of 25 (OH)D3

Question 17

What does PTH respond to?

Answer 17

Falling calcium levels

Question 18

What is the precursor to Vitamin D3 and how is it converted?

Answer 18

7 dehydrocholesterol converted to vitamin D3 in the skin

Question 19

What happens to vitamin D3 in the liver?

Answer 19

It is hydroxylated to 25(OH)D3

Question 20

What happens to 25(OH)D3 in the kidneys?

Answer 20

It is hydroxylated to 1,25(OH)D3 = active metabolite

Question 21

What are the actions of 25(OH)D3?

Answer 21

Gut: transepithelial transport of calcium and phosphate (increase Calcium uptake)
Bone: terminal differentiation of osteoclasts (increased bone resorption)
PTH: -ve feedback to inhibit transcription of PTH

Question 22

Where is calcitonin synthesised?

Answer 22

C cells of thyroid gland

Question 23

What is the general action of calcitonin?

Answer 23

Decrease calcium levels in blood

Question 24

Why does articular cartilage have a limited capacity for repair?

Answer 24

As it is avascular - nutrients only move in an out slowly through synvovium

Question 25

What is a focal lesion?

Answer 25

Small area of cartilage damage

Question 26

What is a chondral lesion?

Answer 26

Lesion within the cartilage but no subchondral bone penetration

Question 27

What is an osteochondral defect?

Answer 27

Lesion in cartilage that penetrates to the subchondral bone

Question 28

Why can osteochondral defects repair better than condral lesions?

Answer 28

As OC defects have access to subchondral blood supply and chondroprojenitor cells whereas chondral lesions do not

Question 29

What is a Grade 1 articular cartilage defect?

Answer 29

fissures into superficial cartilage

Question 30

What is a Grade 2 articular cartilage defect?

Answer 30

multiple fissures extending hald the depth of cartilage

Question 31

What is a Grade 3 articular cartilage defect?

Answer 31

fissures extending full depth of cartilage

Question 32

What is a Grade 4 articular cartilage defect?

Answer 32

complete cartilage loss and subchondral bone exposure

Question 33

What are the 5 current options for treating a small/interediate articular cartilage defect?

Answer 33

``` Debridement Microfracture Osteotomy Osteochondral grafting Autologous chondrocye implantation ```

Question 34

Describe debridement for an articular cartilage defect?

Answer 34

Shave off frayed edged to reduce pain and swelling - no repair but pain relief

Question 35

Describe what microfracturing is in the treatment of an AC defect

Answer 35

Make holes in bone surface to stimulae bleeding and clotting response Fibrocartilage usually forms which is less effective than hyaline

Question 36

When would an osteotomy be performed?

Answer 36

In response to deformed/malaligned joint to avoid wear and tear and re-establish normal loading and gait

Question 37

What is osteochondral grafting?

Answer 37

Taking good cartilage from another siter and adding it to the defect site - can be autograft or allograft

Question 38

What is autologous chrondrocyte implantation?

Answer 38

A regenerative cell based therapy: chondrocytes grown in lab and placed into focal lesion using periostal flap