Bone Pathologies in Horses

Question 1

What is periosteal new bone formation?

Answer 1

• Blunt trauma can lead to sub-periosteal haemorrhage
• Lifting of Periosteum away from the bone
• Stimulates production of periosteal new bone
• Initially less dense and irregular outline
• Becomes more radiopaque with a smooth outline

Question 2

What is sclerosis?

Answer 2

• Densification
• Localised formation of new bone within bone
• Stress
• Protection of a weakened area
• Walling off infection

Question 3

What is bone lysis?

Answer 3

Destrcution in an area of bone
(infection, Neoplasia, Keratoma)

Question 4

What is osteophyte formation?

Answer 4

• Spur of bone on a joint margin
• Joint instability
• Intra-articular disease (e.g OA)

Question 5

What is enthesophyte formation?

Answer 5

New bone formation at attachment of a tendon/ ligament/ joint capsule to bone

Question 6

What is aggressive bone disease?

Answer 6

1. Destrcution of the cortex
2. Character of the periosteal reaction
3. Lack of distinctness of boundary between the bone lesion and normal bone

Question 7

What is ultrasonography useful for?

Answer 7

Used to assess the surface of bone
Bone surface should appear smooth and have uniform thickness of a hyperechoic line

Question 8

How would you use nuclear scintigraphy?

Answer 8

Radioisotope (Technetium 99m) is injected intravenously
➢ Increased Radiopharmaceutical Uptake (IRU) in areas where there is increased osteoblastic activity
➢ High sensitivity but low specificity imaging modality

Question 9

What are the indications of nuclear scintigraphy?

Answer 9

Fracture suspected but no localising clinical signs and negative radiographs
* To assess animals with obscure lameness issues
* Unable to localise with diagnostic analgesia, episodic lameness
* Evaluate horses with poor performance
* Evaluate inaccessible areas e.g pelvic region in the horse

Question 10

What is valgus?

Answer 10

Lateral deviation of limb

Question 10

What is varus?

Answer 10

medial deviation of the limb

Question 11

What is the non-surgical way of treating angular limb deformities?

Answer 11

rest, splints and casts, bandages, hoof manipulation

Question 12

What is the surgical way of treating angular limb deformities?

Answer 12

• Periosteal stripping to stimulate growth
• Growth retardation by bridging the growth plate

Question 13

What is physitis?

Answer 13

Inflammation of the growth plate

Question 14

What is a sequestrum?

Answer 14

Piece of dead radiopaque bone

Question 15

What is involucrum?

Answer 15

Surrounded by an area of lucent granulation tissue

Question 16

What is the sinus?

Answer 16

Radiolucent tract between infected bone and skin

Question 17

How would you treat osteitis and osteomyelitis?

Answer 17

Systemic antimicrobial therapy
Analgesia
Wound care
Curattege
Implant removal

Question 18

What is the prognosis of osteitis and osteomyelitis?

Answer 18

Variable, depends on the severity and chronicity of infection

Question 19

What is the purpose of scintigraphy

Answer 19

• assess areas of increased bone turnover around the joint
• subchondral stress related bone injury
• early diagnosis of OA

Question 20

What is MRI used to assess?

Answer 20

used to assess concurrent soft tissue damage which may be resulting in joint instability

Question 21

What is a contrast study?

Answer 21

• Contrast agent injected into joint and radiographs are taken

Question 22

What is a pressure test?

Answer 22

Distend the joint with sterile saline
* Saline exits through the wound if joint and wound communicate

Question 23

What is the purpose of arthroscopy?

Answer 23

Allows direct visualisation of the joint
* Diagnostic and therapeutic

Question 24

What are the 4 aims of OA management?

Answer 24

• Provide analgesia
• Control articular inflammation
• Limit damage to articular tissues
• Promotes healing of damaged cartilage

Question 25

What is the physical therapy for osteoarthritis?

Answer 25

• Acute = rest, cold therapy
• Chronic= gentle exercise, hydrotherapy

Question 26

What is the anti-inflammatory/ analgesia treatment for osteoarthritis?

Answer 26

• Non-steroidal Anti-Inflammatory drugs
• Most commonly used treatments
• Toxicity concerns

Question 27

What are corticosteroids used for?

Answer 27

• Intra-articular
• Reduction in inflammation in the joint
• May cause laminitis so take care

Question 28

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What are the three adjunctive treatments?

Answer 28

• Hyaluronic acid
• Pentosan Polysulphate Sodium
• Biphosphates

Question 29

What is the pathogenesis of septic arthritis?

Answer 29

• Inflammatory response
• Fibrin clot then traps bacteria
• Cartilage destruction and extension to the subchondral bone
• Results in pain and swelling of the affected joint -> Ultimately leading to degenerative osteoarthritis