Equine foot and skeleton Flashcards
DDx for acute, severe unilateral lameness to foot
Subsolar abscess
Solar bruise
Pedal bone fracture
Aetiology of solar bruise
Blunt trauma to solar surface during locomotion causes haemorrhage into sensitive tissues –> get inflammation inside non-compliant keratinised hoof
So focal increase in pressure and extreme lameness
Risk factors for solar bruises
Uneven or highly concussive surfaces
Barefoot
hacking
Flat floor and low heel conformation e.g in racing TBs
What are corns
Focal bruising at seat of corm; affects shod horses
What is the most common cause of acute severe lameness
Subsolar abscess
Where do subsolar abscesses form
Between senstivie and non-sensitive tissue e.g at white line, seat of corn, frog
How to treat a subsolar abscess
Use paring knife to achieve drainage
Or if can’t do this, place foot poultice to soften sole to help achieve drainage later
How to initially manage acute unilateral lameness vs more mild or multi-limb lameness
Acute unilat: manage as subsolar abscess; bruises will just resolve quickly without pus draining
Mild/multi-limb: box rest and NSAIDs; if just burising will resolve quickly
What is the gold standard imaging method for looking at how FB in good sits within soft tissues
MRI
What is a ketaoma
Space occupying tumour that grows from the coronary band, down hoof wall and exits at white line
Painful as it causes abscesses
If we see recurrent abscesses at the same place in same foot, what should we be suspicious about
keratoma
How do pedal bone fractures present adn change
Presents intially like foot abscess; acute unilat lameness
But improvement is much slower than with abscess
How to diagnose navicular disease
= MRI diagnosis as are looking for inflammation
How to diagnose ossified collateral cartilages
Many sound horses have large ossification of side bones
So need MRI diagnosis to see inflammation here
How might soft tissue issues in the foot present (rather than classic acute severe lameness)
Bilateral insidious progressive lameness
What soft tissue ligament is often positive to distal limb flexion (NB: other aren’t)
Collateral ligaments
What bony changes might we see with collateral ligament disease
Ossified collateral cartilages
Enthesiopathy; bone remodelling at insertion site
How owuld we have to prepare the foot for transcuneal ultrasound
OVernight soaking
Whatis the most common soft tissue injury of the foot
DDFT pathology
Where do we tent to see DDFT pathology and why
Where it changes direction e.g at fetlock, around navicular bone
Because it is less elastic here due to need to resist compression
How can core lesions of tendons e.g DDFT progress
Can propagate proximally/distally over time
So we could do neurectomy to make horse comfortable but if it then propagated above this, would see sudden lameness again
How do sagittal splits of DDFT present, progress and where
Severe lameness but variable over time related to whether split pulled apart
Often at level of navicular
Propagate proximally/distally with time, especially after a neurectomy
Can lead to adhesion formation and burtisi because they involve the tendon surface
How does dorsal border fibrillation in DDFT present!
Cronic low grade degenerative lameness
Get fibrillation of fibres on the dorsal border where they are closely assocaited with the navicular bone
–> Often causes bursitis and adhesion formation
How can we treat DDFT and what structure do we made us of
Focus on navicular bursa to devilver treatment, accessed via tendon sheath
Intrabursal corticosteroids
Navicular bursoscopy for lesions that communication with bursa to break down adhesions and debride fibrillated tissues
Why is it good to debride away fibrillated tissues via navicular bursoscopy
These tissues are drivers of snyovitis
Which lesions is it especially indicated to do navicular busoscopy
Sagittal splits and dorsal fibrillation since these communicate with bursa
What happens if the heel is lower than it should be (we want 5* uphill angle)
Get stressing and increasing loading of the palmar soft tissues
What issues does poor latero-medial foot ballance cause
Increased loading of collateral ligaments, navicular suspensory ligament
What issues do dorsopalmar/plantar impanance cause
Increased loading of palmar/plantar soft tissues = SDFT, DDFT, SL, DSIL
How do bar shoes work
Heart bar provides heel and pedal bone support by transfering load from hoof wall to sole
+ restricts independent movement of heal bulbs
How do graduated pads and shoes work
They are much thicker at the heel than toe and so artifically corrects poor foot balance and reduces strain on DDFT via shortening distance and offloading tendon
Raised heel also alters breakover to happen earluer (this means occurs when itssues at lower stress so better)
Why do we not want to use graduated pads/shoes in longer term
Contributes to making poor foot conformation worse
Farriery for laminitis
pedal bone support via heart bar or pads and packing
Wait until stabilised to shoe
Farriery for navicular syndrome (palmar heel pain)
Use bar shoe to restrict independent heel movement
Farriery for pedal bone fracture
Bar shoe and packing to help immobilise fracture and speed healing
Farriery for horses prone to bruising
Pads and packing to reduce concussive forces
How do we cause lateral flexion to check for pain
Dig nails into one side
What is sternal lift (dynamic thoracolumbar exam)
Apply sustained pressure to sternum to encourage dorsiflexion of cranial thoracic spine
Should have a response which can be maintained
Those with back pain struggle
How to dynamically test to sarcoiliac region
Apply firm pressure to skin either side of tail base
Expect horse to drop hindquarters towards floor and dorsiflex lumbosarcal joint; should hold this for 5-10 secs
= abnormal if there is no respnse, pain signs or unable to maintain
What is different about lumbosacral anatomy in horses
All sacral vertebrae are fused in horse
SI joint is very small; mainly just soft tissue
What is radiculopathy
Neuropathic pain due to compression of spinal nerve root in caudal cervical region
Can cause forelimb lameness
Clinical signs with neck pathology
Neck pain; reduced range of motion in baited stretches
Forelimb lameness; due to cervical muscle dysfunction which are involved in limb protraction, radiculopathy of spinal nerve root feeding brachial plexus causing shooting pain down leg
Ataxia
Prognosis worse from neck pain < radiculopathy < spinal ataxia
When might we see ataxia with neck pathology
With cervical stenotic myelopathy
If we see poor quality canted but fine trot where might this suggest pathology is
In the thoracolumbar spine because there is spinal twist and roll at canter vs just some lateral flexion at trot
How to manage neck pathology
Intra-articular medication with corticosteroids is mainstay to alleviate pain and infammation
Clinical signs of thoracolumbar psine disease
Poor muscling
Pain on palpation
ABnormal dynamic responses (ventral flexion, lateral flextion, sternal lift)
Resenting ridden exercise
Poor quality canter
What is kissing spines
Impingement of the dorsal spinal processes
How to defintiively diagnose dorsal spinous process impingement
First latero-lateral radiography BUT can see this disease in horses without back pain so can’t just use this
- Gamma scintigraphy used to identify areas of remodelling
How does gamma scintigraphy work (diagonsing kissing spine)
INject bisphosphonate with radio-isotope on it which will localise to osteoclasts so highlgihts areas of remodelling
Management of dorsal spinous process impingement
Surgical cranial wedge ostectomy = very invasive procedure to remove chunks of cranial portion of dorsal spinous processes
- Very long, painful recovery but good outcomes
Interpsinous ligament desmotomy to gut interspinous lig and allow back to spread out; short rehab period but doesn’t change underlying anatomy so not really done much; maybe in young racehorses
Typical presentation of lumbosacral and sacroiliac disease
Buckling under saddle
Becoming disunited at canter
Poor hind limb engagement
May have overt lameness
What is a potential risk of blocking the SI joint
THat there is inadvertent blockage of the cranial gluteal nerve which will make horses recumbent for hours
–> Walk straight to stable in case they lie down
Why can we say we are actually medicating SI region rather than joint
Joint very small only 3ml fluid
Vs we inject 15ml on each side
Rehab programs for animals with axial pain
Strengthen core using sternal lifts, dorsiflexion, tail pulls
Water treadmill
Shart non-ridden in school + can use devices to encourage dorsiflexion
HIll work
Pole exercises
Why does fracture line become more radiographically visible after a couple of days
Due to phagocytosis along fracture lines and fragmen end resoprtion
What must we achieve to get primary repair of a fracture
Perfect natomical reduction
Rigid fixation
Sufficient blood supply
Get haversian remodlling to restore previous structural integrity quickly
Why do we want some stress on bone during secondary fracture repair
Otherwise rigid immobility can suppress callous formation
Why do we want a horse to be weight bearing on the lame leg using multi-modal analgesia ASAP
To prevent overloading of the sound leg and severe contralateral lamintiis developing
(happens esp on forelimbs)
What can we do to reduce risk of contralateral laminitis if expected to be non-weight bearing a whole
Soft boots
What fractures are commonly due to repetitive strain injury
Prox phalanx
Lateral condylar fracture
carpal fracture
What joints might we suspect to have microfractures on their way to failure
Joints that repeatedly need to be medicated
Predilection site for stress fracture in racehorses
Distal tibia; lameness that improves with work
Pelvis, vertebrae; more like poor performance
How can a pelvic fracture lead to a fatal bleed
Via displacement and cutting abdominal vessels
What is the safety factor of many structures in equine distal limb
Just 1.2
So easy to go abvoe this with single supraphysiological event
Why might a distal phalanx fracture still look radiographically broken but horse is sound
Because it had headed by fibrous malunion
What does quick infill of fibrous tissue in distal phalanx fracture mean for surgical prospects
Not such good surgical candidates
When do proximal sesamoid bone fractures commonly occur
During fast work
So see with racehorses commonly
What are common sites from fracture due to external trauma e.g kick
Dorsomedial radius as nothing between skin and bone to take force
Dorsomedial tibia
If a horse has had direct trauma and shows a wound but no fracture visible on X ray what do we do
Put in cross ties anyway; fracture may just not be visitble
Why do we put a splint on the carpus for an olecranon fractures
This allows it to be used as a crutch for enough movement to walk onto lorry for transport
How to do an ethmogram for ortho pain behaviour and how many signs must a horse have to be suggestive of orthopaedic pain focsu
Ride and walk/trot for 10-15 mins
If have >8/24 of the behaviours, suggestive of ortho pain
