General

Question 1

What info can allow you to gain a subjective assessment of the current lameness?

Answer 1

Hx of trauma, duration, deterioration/ improvement, circumstances, effects of exercise, management changes

Question 2

What factors do you assess by distance examination?

Answer 2

Symmetry, posture, conformation

Question 3

What factors does an objective assessment of lameness include?

Answer 3

Distance exam, observation of gait, palpation and hoof testers, manipulation of joints

Question 4

What does manipulation of joints assess?

Answer 4

Determine ROM/ abnormal movement, pain related to movement, load/ unload specific structures in the limb

Question 5

What is a varus/ valgus deformity?

Answer 5

A deformity involving oblique displacement of part of a limb away from the midline.

Question 6

What is the safety factor?

Answer 6

Max stress a structure withstands until breakage divided by stress mostly to undergo in its lifetime

Question 7

How do you calculate stress?

Answer 7

Force/ CSA

Question 8

What are the different types of force and which structures undergo them?

Answer 8

Tension- tendons, bones
Compression- joints, bones
Bending- bones
Shear- joints

Question 9

What is the cause secondary nutritional hyperparathyroidism?

Answer 9

Low dietary Ca–>incr PTH–> incr Ca release from bone. Kidney releases vit D increases Ca release from bone and Ca absorption from intestine.

Question 10

What is secondary renal hyperparathyroidism?

Answer 10

CRF (normally adult). Decr activation of D. Lowered PO4 excretion (PO4 binds to Ca, serum Ca lowered)
Incr PTH drive and effects on bonees

Question 11

What is MBD of reptiles and chelonians?

Answer 11

Low diet Ca. Decr activation/ availability of vit D. Lethargy, lameness- joint/ limb swelling, muscular tone and atrophy.

Question 12

How is MBD of reptiles and chelonians diagnosed?

Answer 12

Radiography- joints, limbs and spine, egg binding, spontaneous fractures.
Blood sample- low Ca.
Confirmation- swollen bones, poor density, misshapen, pliant mandibles, lethargy, unable to lift body off ground, path fractures and low serum Ca (tail vein

Question 13

How is MBD of reptiles and chelonians treated?

Answer 13

Ca gluconate, dietary adjustment (2% Ca diet), UV light and or direct sunlight (not through glass), monitor blood Ca

Question 14

What are the components of hyaline cartilage and where is it found?

Answer 14

Provides interface between bones at a synovial joint.

Cartilage, PGs, water. To resist compressive forces. Chondrocytes responsible for turnover of matrix

Question 15

What is osteochondrosis?

Answer 15

Group of conditions of developing cartilage and its supporting bone. Initiated by a vascular problem in the epiphysis, failure of normal cartilage to bone succession.

Question 16

What is osteochondritis dissecans?

Answer 16

Detachment of a chondral or osteochondral fragment from the articular surface.

Question 17

What conditions occur in fast growing high performance patients?

Answer 17

Dogs- OCD, FCP (fragmented coronoid process), UAP (united anconeal process)
Horses- OCD, SBC (subchondral cystic lesions)
Pigs- OCD esp hip
Broiler chickens- OCD stifle

Question 18

What is the classical presentation of osteochondrosis?

Answer 18

Young, fast growing, large, pure bred. Joint effusion- inconsistent. Often bilateral. Lameness variable. Sub clinical dz possible.

Question 19

What is canine elbow dysplasia?

Answer 19

Osteochondrosis is 1ry dz in this syndrome. Incl- humeral osteochondritis dessecans (OCD), FCP, UAP, 2ry OA. Combo of some or all

Question 20

How does osteochondrosis cause osteoarthritis?

Answer 20

Direct irritation, direct cartilage damage, incongruency, mechanical incompetence. Cycle of reaction to these factors. The 2 are intimately linked together. Often temp stabilises in young adult as osteochondrosis gone away- left w/ degree of diability e.g. loss of ROM but not a great problem w/ OA.

Question 21

What is the most common medication for orthopaedic problems?

Answer 21

NSAIDS- inexpensive and efficient

Question 22

How do NSAIDs work and what are some common side effects of their use?

Answer 22

Inhibit COX therefore PG synthesis- this decreases synovitis, reduces cartilage degradation and prevents sensitisation of pain receptors
GI ulceration, nephritis, PLE, -ve influence on cartilage and bone metabolism

Question 23

What is the mechanism of corticosteroids?

Answer 23

Inhibit PG synthesis (block PL A and COX pathways). Inhibit synthesis of cartilage degrading cytokines (IL1 and TNF-a). Inhibit cartialge-degrading enzymes (matrix metallowproteinases, aggrecanase-1)

Question 24

What are the side effects of intra-articular steroids?

Answer 24

-ve effects on cartilage metabolism and healing. Incr risk of iatrogenic joint infections. Laminitis (although extremely rare)

Question 25

What are the functions of cartilage?

Answer 25

Template for bone growth, resists compression, resilience, support, flexibility, lubrication and movement at diarthrodial joints

Question 26

Where do you find hyaline cartilage (type II coll)?

Answer 26

Articular cartilage, nasal septum, trachea and bronchi, ventral end of ribs, embryonic skeleton, epiphyseal growth plate

Question 27

Where do you find fibrocartilage (type II and type I coll)?

Answer 27

IV disc, meniscus

Question 28

Where do you find elastic cartilage (type II coll w/ elastin and also some type I coll)?

Answer 28

Epiglottis | Ear

Question 29

What are the general characteristics of cartilage?

Answer 29

Chondrocytes- synthesis all the ECM Avascular- no new supply of cells, poor capacity to repair Aneural ECM- major component coll II and often type I present, PGs

Question 30

How does cartilage get its blood supply?

Answer 30

Via vascularised subchondral bone and the synovial surface

Question 31

What are the physical properties of the components of cartilage?

Answer 31

Aggrecan- resilience and compressive resistance | Collagen- tensile strength

Question 32

How does the thickness of cartilage differ between congruent and incongruent joints?

Answer 32

Congruent: thin cartilage deforms only a small amount, yet the area is sufficiently large to distribute low and maintain low stress Incongruent: deformation of the thick cartilage incr SA under compression sufficiently to decr the stress appropriately

Question 33

Which 3 components of collagen determine its mechanical behaviour?

Answer 33

Water Collagen- increases stiffness- disruption in OA decreases strength Proteoglycans

Question 34

What are the risk factors of osteoarthritis?

Answer 34

Age- thinning of cartilage Genetic factors incl M/F bias Environmental Mechanical Trauma

Question 35

Why is age a contributing risk factor for osteoarthritis?

Answer 35

Thinning of cartilage Junk accumulation- loss of PGs, accumulation of junk degraded products, altered activity of cells in response Reduce GF response

Question 36

How do cell alterations with age in cartilage contribute to risk factors of OA?

Answer 36

Cellularity decr w/ advanced age- fewer to maintain ECM, fewer stem cells Calcification of ECM incr Proliferation of chondrocytes reduced

Question 37

What are enthesocytes and osteophytes?

Answer 37

Enthesocytes- abnormal projections at attachment of tendons and ligaments Osteophytes- abnormal projections in joint spaces