Axial Skeleton

Question 1

How many cervical vertebrae does a horse have?

Answer 1

7

Question 2

Which cervical vertebrae have no specific identifiable features?

Answer 2

3rd, 4th and 5th

Question 3

What is the name given to C1?

Answer 3

Atlas

Question 4

What is the name given to C2?

Answer 4

Axis

Question 5

Describe the features of C1

Answer 5

Develops in two lateral halves which gradually ossify

Question 6

Describe the features of C2

Answer 6

• Separate centres of ossification for the dens, head, body and caudal epiphysis.
• The dens fuses with the head at approx 7 months

Question 7

Compare the difference in size between C5, C6 and C7

Answer 7

C6 is shorter than C5
C7 is shorter than C6

Question 8

Which cervical vertebrae may have a small dorsal spinous process which may be fairly prominant?

Answer 8

C7

Question 9

How is T1 recognised?

Answer 9

Large dorsal spinous process

Question 10

What are the presenting clinical signs of neck pain

Answer 10

• Neck stiffness/pain/ ”locking”
• Acute trauma
• Poor performance/ problems performing specific manoeuvres
• Ataxia (usually low grade but can be severe)

Question 11

How can the neck be examined?

Answer 11

• Visualisation: position, head carriage, position of limbs/gait
• Palpation: symmetry, atrophy, pain, fasciculations/spasm
• Range of motion: lateral, dorso-ventral flexion
• Neurological exam
• Dynamic exam: walking, trot, lunge, ridden

Question 12

Which 4 issues to be ruled out when examining the neck?

Answer 12

• Lameness
• Back problems
• Tack issues
• Dentistry

Question 13

Name 3 common conditions of the neck

Answer 13

Developmental - Cervical Vertebral Malformation
Degenerative - Osteoarthritis
Trauma - fractures

Question 14

Name 3 rare conditions of the neck

Answer 14

Neoplasia
Congenital malformations
Infectious

Question 15

‘Wobblers’ is a name given to which condition?

Answer 15

Cervical vertebral malformation

Question 16

Which horses are predisposed to CVM?

Answer 16

Warmbloods, thoroughbreds

Question 17

How does CVM appear on radiography

Answer 17

Varying spectrums of malformation of bones
- Narrowed spinal canal
- Luxations between vertebrae
- Arthritis

Question 18

Describe the features of cervical osteoarthritis

Answer 18

• Aetiology: age, CVM, previous trauma
• Cartilage erosion and subchondral bone sclerosis
• Periarticular osteophytosis
• Synovial cysts/soft tissue hypertrophy

Question 19

How is cervical OA treated?

Answer 19

• NSAIDs
• IA medications: corticosteroids, hyaluranon
• Physiotherapy
• Exercise
• Often palliative Tx only

Question 20

What are the 3 negative prognostic indicators for cervical OA?

Answer 20

Severity of signs/radiographs
Young horse
Ataxia

Question 21

How do cervical fractures occur?

Answer 21

NH racehorses, event horses, point to point more at risk
Field injury/freak accident also possible
- Kicks from other horses
- Car accidents
- Horse running into objects because of fright

Question 22

What is the prognosis of a cervical fracture?

Answer 22

• Dependant on location, configuration, open vs closed, single or polyostotic
• Many are not treatable
• Conservative treatment is often only realistic chance
• Surgical repair – isolated reports in literature

Question 23

How many thoracic vertebrae are there in the horse?

Answer 23

18
13 in dog and cat

Question 24

How many lumbar vertebrae does a horse have?

Answer 24

6
7 in dog

Question 25

Which thoracic vertebrae is most identifiable? Why?

Answer 25

T15 - vertically inclined, the ones proximal of this are sloped caudally and the distal ones are sloped cranially

Question 26

What are the presenting signs of thoracolumbar spine conditions?

Answer 26

- Poor performance - Behavioural changes - Uncomfortable when ridden/ “doesn’t feel right” - Stiffness in the back - Back spasms - Difficulty in being tacked up - Bucking/rearing

Question 27

How would diseases of the thoracolumbar spine present on physical exam?

Answer 27

- Specific to the back - Obvious swellings: fractured withers/acute supraspinous desmitis/muscle haematoma/poor fitting saddle - Presence of white hairs: may represent poor saddle fit, esp behind withers

Question 28

How would diseases of the thoracolumbar spine present on palpation?

Answer 28

Abnormal reactions include: - Ears back/teeth grinding/biting/kicking/tail swishing - Muscle fasciculations - Guarding or splinting of back in anticipation - Bucking/rearing

Question 29

How can you flex a horses back?

Answer 29

Use blunt object Cranial to caudal then lateral - Thoracolumbar extension then thoracolumbar flexion - Lateral excursion away from stimulus (lateroflexion) - Note breed differences (TB versus Cob)

Question 30

Which part of a dynamic exam is most useful for back examination?

Answer 30

Lunge - Muscle fasciculations/spasms/guarding/splinting - Breaking into canter - Head held forward/neck extended - Lack of hindlimb impulsion

Question 31

How does fractures of the withers occur?

Answer 31

Trauma - falling over backwards

Question 32

How is fracture of the withers managed?

Answer 32

Rest = 2-3months box rest NSAIDs Fibrous union Long-term outcome fair/good

Question 33

How is saddle induced trauma treated?

Answer 33

Rest/ice Ultrasound therapy Low-powered laser for indolent wounds Correct inciting cause

Question 34

Which ligament can be damaged in the back?

Answer 34

Supraspinous

Question 35

What are the clinical signs of supraspinous ligament damage?

Answer 35

- Rigid gait/head elevated/reduced stride - Heat/pain/swelling (acute) - Thickening (chronic)

Question 36

How is supraspinous ligament damage diagnosed?

Answer 36

US

Question 37

How is supraspinous ligament damage treated? acute vs chronic?

Answer 37

Acute: Cold compress/NSAIDs/Rest Chronic: Physiotherapy (e.g. therapeutic ultrasound; Equissage; stretching/belly lifts); showckwave (?)

Question 38

How is impingement of the dorsal spinous processes diagnosed?

Answer 38

Common finding! Probable conformational as well as degenerative underlying aetiology Radiography: - Confirm significance - Intra-lesional LA - Exclude other causes of pain first

Question 39

How is impingement of the dorsal spinous processes treated?

Answer 39

1. Medical/Conservative e.g. PBZ, shockwave therapy, physiotherapy e.g. removal of dorsal spinous processe 2. Surgical = Remove all or part of the affected DSP’s

Question 40

Describe the anatomical features of the lumbar spine

Answer 40

- Wide transverse processes and wide dorsal spinous processes - A lot of fat and muscle in the area can make it hard to radiograph - 6 vertebrae