Large Animal MSK Exam 1

What are the causes of lameness?

pain, mechanical restriction, neurologic deficit

What are you looking for during large animal palpation?

sensitivity, heat, soft tissue swelling, effusion, asymmetry

If a horse is more lame on a hard surface, what does this indicate?

likely a bone issue

If a horse is lame on a soft surface, what does this indicate?

likely a soft tissue issue

When is a ridden exam helpful?

when lameness only occurs during a very specific movement

Which gait is not really used for evaluation in horses?

gallop

What is a grade 5 lameness?

non-weight bearing

What is a grade 4 lameness?

lame at the walk

What is a grade 3 lameness?

lame at the trot under all circumstances

What is a grade 2 lameness?

consistently lame at the trot under certain circumstances

What is a grade 1 lameness?

inconsistently lame at the trot under certain circumstances

What is the goal of performing flexions during lameness exam?

evaluate change in gait after stressing a particular joint

What are you looking for when assessing hind limb lameness?

increased gluteal exertion, hip drop/hike

What are some other signs of hindlimb lameness?

-shortened cranial stride

-axial placement of hindlimb

-slow to advance

-reduced stance duration

-incorrect lead

-head shaking/tail swishing

What are the purpose of hoof testers?

test for sensitivity and pain on wall, sole, frog, and heel bulbs

How to identify forelimb lameness in a horse?

-up=ow

-down on the sound

What is the purpose of nerve blocking?

-to identify the source of lameness

-pain management

What are the contradictions of nerve blocking?

-local inflammation

-cellulitis

-dermatitis

-fracture suspicion

-laminitis

What is the common local anesthetic used for nerve blocking?

carbocaine

T or F: you should place the nerve block proximally

False

When should you evaluate the horse after blocking?

5 minutes to prevent diffusion of block

T or F: The majority of forelimb lameness originates from the fetlock down

True

What does the palmar digital nerve block?

-digital cushion

-navicular bone and bursa

-digital aspect of deep digital flexor

-entire sole

-impar ligament

-palmar aspect of distal interphalangeal joint

What does the abaxial/basisesamoid nerve block?

-all included in PDN

-entire distal phalangeal joint

-entire proximal interphalangeal joint

-dorsal hoof wall

-superficial digital flexor

-deep digital flexor

-straight and oblique sesamoid ligaments

-collateral ligaments

-some of metacarpophalangeal

What is does the low 4 point block?

-all included in abaxial block

-entire metacarpophalangeal

-suspensory branches

Traits of a perineural block

-easy

-low risk

-less specific

-better at identifying distal limb causes

Traits of intrasynovial block

-difficult

-more risk

-more specific

-better at identifying proximal limb causes

What complications can occur during a perineural block?

-hematoma, specifically for low 4 point

-needle breakage

-cellulitis

-aseptic prep

What complications can occur with an intrasynovial block?

-needle breakage

-joint flare acute inflammation

-synovial infection

T or F: imaging is typically used before lameness is localized

False

Traits of radiographs

-inexpensive

-in field

-performed standing

-gives bone information

-low sensitivity

-minimal soft tissue information

-limited axial skeleton imaging

Traits of CT

-3D

-bone information

-expensive

-hospital procedure

-requires anesthesia

-limited soft tissue information

Traits of ultrasound

-inexpensive

-in field

-standing

-soft tissue and bone surface info

-reduced resolution

Traits of MRI

-3D

-gives soft tissue and bone detail

-expensive

-hospital

-anesthesia

-must have lameness localized

-cannot image axial skeleton

Traits of bone scan

-localizes well

-standing procedure

-hospital

-expensive

-tell where the problem is, not what

Traits of PET scan

-function tissue assessment

-standing

-can differentiate active vs inactive lesion

-hospital

-expensive

-helpful when combined with CT or MRI

-not available for axial skeleton