arthritis

Question 1

what is arthritis

Answer 1

inflammation/degeneration of the joint

Question 2

what is osteoarthritis

Answer 2

a degenerative condition ultimatley leading to cartilage breakdown and loss of function. (known as disease of articular cartilage)

Question 3

what is a diarthrodial (synovial) joint and what are the 4 types

Answer 3

a specialised joint consisting of a synovial cavity allowing articulation between 2 or more bones

1. Ball & socket (coxofemoral)
2. hinge
3. gliding (tarsometatarsal, acromioclavicular)
4. pivot (atlantooccipital)

Question 4

4 components of a synovial joints anatomy

Answer 4

hyaline cartilage covered bones. (articulate cartilage and subchondral bone have an intimate relationship)

synovial fluid: ultrafiltrate of plasma plus protein (hyaluronic acid)

fibrous joint capsule: synovial membrane, supporting ligaments/tendons, nerves and blood vessles

Question 5

what cells are responsible for maintainance of the matrix of the articular cartilage

Answer 5

chondrocytes

matrix consists of collagen, proteoglycans and water

Question 6

what are the changes seen in osteoarthritic joints

Answer 6

subchondral bone remodelling
osteophyte formation
synovial inflammation and fibrosis
cartilage lesion and degredation
neoangiogenesis and neurogenesis

Question 7

what are predisposing factors for osteoarthritis

Answer 7

exercise/trauma/biomechanics
developmental orthopaedic disease (hip dysplasia, osteochondrosis)
obesity
genetics
sepsis
medications (corticosteroids)
ageing

Question 8

what is seen in a radiograph of an arthritic joint

8 features in total

Answer 8

soft tissue swelling
osteophytosis
enthesiophytosis
subchondral bone sclerosis
intra-articular mineralisation
fragmentation
collapsed joint space
subchondral bone cysts

Question 9

what are your options for medical managment of osteoarthritis

Answer 9

NSAIDS
corticosteroids
hyaluronic acid
pentosan polysulphate
biphosphonates

Question 10

how does NSAIDs work

Answer 10

COX inhibitors

anti inflammatory and analgesic affects

Question 11

how does corticosteroids work

Answer 11

bind to cytoplasmic nuclear receptors and inhibit cytokines

Question 12

how does hyaluronic acid work

Answer 12

it is an important component of synovial fluid and articular cartilage.
many properties such as improve viscosity, stimulate proteoglycan synthesis etc,.

Question 13

how does pentosan polysulphate sodium work

Answer 13

enhances proteoglycan synthesis and reduces articular cartilage fibrillation

Question 14

how does biphosphonates work

Answer 14

potent inhibitors of bone resorbtion through inhibition of osteoclasts

Question 15

other than radiograph how else can you diagnose the joint.

Answer 15

arthroscopy

Question 16

what is immune mediated joint disease called

whats the two forms of this disease

Answer 16

polyarthritis

erosive and non erosive

Question 17

what are the pathophysiological events that occur in polyarthritis

Answer 17

chronic antigenic stimulation within synovium leading to inappropriate immune response and development of immune complexes

Question 18

how would you diagnose IMPA

Answer 18

multiple joint/limb swelling, generalised stiffness, shifting lameness, neck pain, lethargy,

Question 19

how would you manage IMPA

Answer 19

corticosteroids

Question 20

what are three common causes of infective arthritis (synovial sepsis)

usually due to bacteria entering joint

Answer 20

haematogenous (navel ill)
trauma/wound
iatrogenic

Question 21

whats the pathophysiology of synovial sepsis

Answer 21

a marked inflammatory response with vasodilation and influx of neutrophils.
Fibrin clots trap and protect bacteria.
leads to cartilage destruction and extends to subchondral bone

Question 22

how does normal synovial fluid look

Answer 22

pale yellow
high viscosity
WBC<1x10^9
total protein<20g/l
<10% neutrophils

Question 23

how does septic synovial fluid look like

Answer 23

serosanguinous, turbid, reduced viscosity
high WBC and protein content
>90% neutrophils

Question 24

how would you treat synovial sepsis

3 steps

Answer 24

1. treat underlying cause/agent
2. systemic and local antimicobials
3. removal of inflammatory mediators (joint lavage)