Lecture 36 4/24/25 Flashcards
What are the characteristics of hoof radiographs?
-“podiatry” views assess overall hoof balance
-normal workup includes dorsopalmar and lateral views
-need to use a calibration device to ensure accurate measurements
-want to place barium dot on sole at point of frog and barium strip on dorsal hoof starting at hair line
Which additional views can be done to assess the hoof?
-navicular/sky line view
-DP65 view
What are the characteristics of medial-lateral balance?
-measure down from P3 to a known point on medial and lateral sides
-should be within 1 to 2 mm; can have some variability due to human error
What are the characteristics of dorsopalmar/plantar balance?
draw a vertical line down from approximate center of rotation of the distal interphalangeal/coffin joint
-measure distance of the weight bearing surface dorsal and caudal to this line
-should be approximately a 50/50 ratio
What are the characteristics of sole depth?
-measure solar surface of distal interphalangeal/coffin bone to the most superficial aspect of barium dot
-use the calibration device to combat magnification and calculate true measurement
-ideal thickness is 12 to 15 mm
What are the characteristics of hoof pastern axis?
-long axis of P1, P2, and P3 should be one straight line
-any deviation from straight is inappropriate
-bending towards the caudal aspect is “broken back”
-bending towards the cranial aspect is “broken forward”
What is “broken forward” associated with?
-hyperflexion of the DIP joint/club foot
-ventral rotation
What is “broken back” associated with?
flat (0 degree) or negative palmar/plantar angle
What are the characteristics of palmar/plantar angle?
-angle of solar margin of distal phalanx/coffin bone with the environment
-can use shoe or block as a line
-should be a positive 2 to 5 degrees
-depends on individual horse conformation
-goal is a straight hoof pastern axis
-if angle is at the back of the hoof, the heel is lower than the toe and the angle is negative
What are the characteristics of ventral rotation?
-dorsal P3 should be parallel to the dorsal hoof wall and the hoof-lamellar interface
-methods include angle difference or distance between P3 and HL zone/hoof wall at proximal and distal aspect
What are the characteristics of lamellar stretching/wedging?
when the lamina becomes wedge-shaped/stretches away from the hoof wall
What are the characteristics of ventral displacement/sinking?
-dorsal barium ALWAYS starts at hairline of coronary band
-can only definitively determine sinking with repeat rads
-measure the distance between the hairline of coronary band and the extensor process of P3
What are the characteristics of therapeutic shoeing?
-done to restore “ideal” alignment and balance
-helps to unload certain structures like the DDFT
-helps to protect thin soles
What is the shoeing strategy for thin soles?
provide protection with a leather or plastic pad
What is the shoeing strategy for dorso-palmar imbalance?
-set shoe back from the toe
-dress toe back
-reduce “break over” with rolled toe
What is the shoeing strategy for issues with hoof pastern axis/flat or negative palmar angle?
-frog support wedge pad
-rocker toe or full rocker shoe
What are the characteristics of subsolar abscesses?
-grade 4/5 lameness
-increased digital pulses
-positive to hoof tester pressure
-palmar digital or abaxial nerve blocks will relieve pain
-pocket of fluid +/- gas within hoof capsule that can break through the sole or coronary band
When are subsolar abscesses radiographically evident?
only if GAS is present
What is the treatment for subsolar abscesses?
-establish drainage
-open hole is sole
-possible poultice to soften foot and provide osmotic pull on abscess
-keep debris from packing in hole (hoof bandage)
-determine need for tx shoe once drainage stops
What is the prognosis for primary subsolar abscesses?
-excellent for life
-excellent for athletic career
What can cause secondary subsolar abscesses?
-laminitis
-pedal osteitis
-keratoma
-chronic foreign body/gravel
What is the further treatment for recurrent subsolar abscesses?
-radiographs
-possible CT
-referral
What is navicular degeneration?
inflammation and/or degeneration of the navicular bone and/or associated soft tissues
What is the typical exam in navicular degeneration?
-grade 3/5 lameness that may be shifting
-switching of lameness after palmar digital nerve block
-positive hoof tester response at heels
Which radiographs are used to assess navicular degeneration?
-podiatry MDB
-DP65
-navicular skyline
What are the 3 radiographic findings that definitively diagnose navicular degeneration?
-medullary sclerosis
-flexor cortex erosion
-intramedullary cyst
What are the characteristics of medullary sclerosis?
-loss of cortico-medullary distinction
-generalized “opaque” look to the bone
What are the characteristics of flexor cortex erosions?
-lysis or change in shape of flexor surface
-concurrent sclerosis on other side of erosions
What are the characteristics of intramedullary cyst?
-widening of vascular channels or 2 vascular channels coalescing
-vascular channels are normal but widening/coalescing is not
What findings can be associated with navicular degeneration?
-greater than 7 vascular channels
-distal border fragmentation
-suspensory ligament enthesiopathy (smiley face appearance)
What is the treatment for navicular generation?
-therapeutic shoeing to provide heel support, improve DP imbalance, and reduce load of DDFT
-intra-articular steroids
-systemic NSAIDs
-bisphosphonates
-palmar digital neurectomy
What is the prognosis for navicular degeneration?
-good for life/pasture soundness
-guarded to good for athletic career
-lower prognosis with flexor cortex lesions or concurrent DDFT lesions
-may have a longer career if dropped down in “class”
-will always progress; tx is focused on slowing progression
What are the characteristics of DDFT tendinopathy?
-fiber disruption in DDFT
-usually at the level of proximal recess of the navicular bursa
-can extend all the way to the insertion on P3
-similar presentation to navicular dz; can occur concurrently
-present with 3/5 lameness that resolves with PD or abaxial nerve blocks
-can be bilateral and cause shifting lameness
-often have a history of DIP joint injections that helped for a few weeks before return of lameness
What is the treatment for DDFT tendinopathy?
-therapeutic shoeing to improve balance and unload DDFT
-rest
-possible steroid injections
-possible shockwave
-possible surgical debridement
What is the prognosis for DDFT tendinopathy?
-guarded to guard for life/pasture soundness
-dependent on profession for athletic career
-fair to guarded for speed and jumping
-guarded to good for trails
What are the characteristics of DIP joint osteoarthritis?
-cartilage degeneration leads to joint inflammation, pain, and bony change
-grade 3/5 lameness
-occurs in forelimbs
-bilateral with shifting lameness
-resolves with PD or abaxial nerve blocks
-will see periarticular bone formation on radiographs
What is the treatment for DIP joint osteoarthritis?
-intra-articular anti-inflammatories
-IRAP if early/mild
-polyacrylamide gel if end stage
-systemic NSAIDs
-therapeutic shoeing
What are the characteristics of laminitis?
-inflammation of the lamina
-may result in detachment; rotation, sinking, and/or chronic abscesses
What can cause laminitits/
-systemic illness
-equine metabolic syndrome
-pars pituitary intermedia dysfunction/cushing’s
-mechanical
What is the treatment for laminitis?
-therapeutic shoeing
-pain control
-anti-inflammatories
-resolve underlying cause
What is the prognosis for laminitis?
-about a 50% success rate for any treatment
-prognosis depends on degree of radiographic change
-guarded to good for life w/o sinking or rotation
-fair to guarded for athletics w/o sinking or rotation
-guarded for life w/ sinking and rotation
-poor to fair for athletics with sinking and rotation
-neg. prognostic indicators include sinking, greater than 7 deg. rotation, and acute-on-chronic onset
