Large Animal Sx- Conditions of the equine foot (specific probs) 1

drraythe's version from 2016-04-29 16:03

P3 fxs, navi bone fx, hoof wall cracks, Hoof Wall Avulsions, Heel Bulb and Coronary Band Lacerations

Question Answer
Fractures of the Distal Phalanx--> etiology?Trauma! such as High speed impact- racing (Standardbreds). Paddock injury. Kick solid object. Penetrating wound
what are the two ways to classify fractures of the distal phalanx?"type 1-6" or "articular vs non-articular"
how might lameness from laminitis differ from a P3 fx in a really basic way?laminitis is usually in either both front feet or ALL feet, whereas a fracture is usually just in one
what are the clinical signs of a P3 fracture?Acute severe lameness, +/- Increased digital pulses, Pain on hoof testers, Articular fractures-->Effusion of coffin joint
which "Type" P3 fracture is most common?TYPE 2- ARTICULAR
Classification of P3 Fractures--> Type 1Non-articular (common)
Classification of P3 Fractures--> Type 2Articular (Most common P3 fracture)
Classification of P3 Fractures--> Type 3Articular, saggital, Uncommon
Classification of P3 Fractures--> Type 4Articular, Extensor process, Forelimbs. Common.
Classification of P3 Fractures--> Type 5Multifragment, severe lameness and POOR PROG
Classification of P3 Fractures--> Type 6Solar margin...Common + underdiagnosed
which "type" classification has the worst prognosis?type 5- multifragment leading to severe lameness
much of the prognosis of a P3 fracture depends on if...articular or not
**P3 fractures are often hard to see on rads, esp. if they arent displaced. Of course you should take mult. views, but what is something you can do if no matter what you can't seem to find the fracture but are pretty sure it's there?WAIT 10-14 days...for a bone to heal it must be remodeled via osteoclasts, which will first make the gap BIGGER before the osteoblasts come in to secrete new bone. When the gap is bigger, take your picture!
you take a radiograph and you see all these lines in the navicular bone- how concerned should you be? not at all. this is NORMAL-- radiating vascular channels
what kinda fx is this? Type 1 (non-articular)
what kinda fx is this? Type 5 (multifragment)
what kinda fx is this? Type 3 (articular, sagittal)
what kinda fx is this? Type 2 (articular)
what kinda fx is this? Type 4 (extensor process)
what kinda fx is this? Type 1 (non-articular)
Treatment of P3 Fractures--> NON-ARTICULAR fracturesPrevent expansion of hoof wall, Bar shoes with clips, Rim shoe, Fiberglass casting tape, Rest
Treatment of P3 Fractures--> Articular Fractures--> conservative tx?Prevent hoof wall expansion, rest
Treatment of P3 Fractures--> Articular Fractures--> internal fixation (how do you do this?)Lag screw, Sagittal or oblique. Can use to Reconstruct articular margin
when would you want to consider internal fixation?articular fractures (horses >3yrs)
Prognosis of P3 Fractures?Generally good, but Failure to reconstruct articular surface decreases prognosis
Failure to reconstruct articular surface of P3 fx...what condition can this lead to? how is healing time affected?Can lead to osteoarthritis, and also inc time for healing (6-12 months convalescence). May not heal radiographically!
Fractures of the Navicular Bone--> etiology?(1) trauma (2) Pathologic fracture (infection, Chronic navicular syndrome, setting the bone up to be easily fractured)
clinical signs of a navicular bone fracture?Acute severe lameness, Sensitive to hoof testers, Chronic lameness increases by exercise
Unfortunately the sulci of the hoof often overlie the navicular bone on radiograps. If the sulci are not packed well enough, it could LOOK like the nav bone is fx. how would you make sure that you have a fx and not an artifact?if the dark like STOPS at the border of the navi bone, prolly fracture, bc the sulci would extend their radiolucency past the navi bone onto the rest of the rad
You take a rad of a horse's hoof, and you see there is a giant crack through the navicular bone!! what do?don't freak- take rad of other foot first. Some horses have bipartite or even Tripartite navis....if the other foot has it too, prolly just a bipartate navi.
Treatment for navicular bone fx?Rest, Prevent expansion of hoof capsule, Bar shoe with clips (bar shoes are the complete circle shoes, and clips are little hedges that come up to make contact with the wall of the hoof-- both offer more support), Neurectomy for chronic lameness, Heel wedge- reduce DDFT pressure on navicular, Surgical fixation – lag screw
prog of a navi bone fx?poor (theyre uncommon tho)
Etiology of hoof wall cracks?Poor quality horn, Poor hoof trimming, Rotation of P3/ laminitis, Conformation, Adverse weather, Secondary to abscess, Chronic SE (Selenium) toxicity
how can Poor hoof trimming lead to hoof cracks? (specific probs the ferrier causes)Neglect, Low, under run heels, long toe, Flat soles
Rotation of P3/ laminitis leads to a hoof crack where?toe crack
can hoof wall cracks cause lameness?yes, but only if sensitive soft tissue (laminae) is involved. This is esp true for quarter and heel cracks
clinical signs of hoof wall cracks?Lameness - only if crack involves sensitive laminae (usually quarter or heel cracks, may or may not be bleeding), Instability of hoof wall, Variable sensitivity to hoof testers
best way to dx hoof wall cracks, aside from seeing them?hoof testers (could also use Perineural anesthesia and maybe rads if you wanted)
prog of hoof wall cracks?good to guarded, May recur if predisposing factors not addressed
how do you tx a hoof wall crack if it is minor?#1- Remove inciting cause!! provide Appropriate trimming (trim wall at ground surface) and consider a bar shoe
how do you tx a hoof wall crack if it is large or unstable?#1- Remove inciting cause!! First Debride unattached and necrotic horn. Then provide stabilization, then give Topical therapy, possibly supplement with Biotin and methionine
what are some things you can use to stabilize a large hoof wall crack?Bar shoe, Acrylic patch, Wire suture, Plate, Screws and wire
if there is infection/necrosis of the hoof wall crack, what must you do to tx?Debridement using sharp dissection or a motorized tool
what might result in a PERMANENT hoof crack?if it goes the way up to the coronary band and damages the soft tissue there, and that tissue scars, that part wont be able to produce any more horn and there will be a perm crack
Hoof Wall Avulsions, Heel Bulb and Coronary Band Lacerations--> complete vs incomplete?Complete=Tissue is totally removed. Incomplete=Border remains
how do Hoof Wall Avulsions usually occur?TRAUMA! Kicking a wall, door, etc, Trailer accidents, Foot caught in fence/ paneling
clinical signs of hoof wall avulsions?Variable lameness (often severe), Sensitivity to palpation, Hemorrhage (shock), instability
coronary band vs corium?coronary band-- location at junction of hair and hoof. corium is the tissue which produces the hoof.
how do you treat a hoof wall avulsion that is Incomplete with no coronary band involvement? Prog?Removal of detached horn, Debridement and lavage, Bar Shoe, Bandaging, +/- antibiotics, Tetanus prophylaxis. GOOD PROG!
how do you treat a hoof wall avulsion that is Incomplete Avulsion with coronary band involvement?Debridement, Closure, Immobilization... OR: Convert to Complete Avulsion. (Avulsion Coronary band defects may result in permanent defects in the hoof growth!)
what should you know about the coronary band if it is damaged from an avulsion? Coronary band defects may result in permanent defects in the hoof growth!
how do you treat a hoof wall avulsion that is Complete Avulsion? (note if stable or unstable defect)Stable: BANDAGE! Unstable/larger: Cast immobilization
If you have a hoof avulsion which has Involvement of synovial structures, how do you tx?Broad spectrum IV antibiotics, Regional perfusion, Lavage (Arthroscopic) (on top of stabalization, most likely cast)

Corns and Bruised Soles, thrush, canker, keratoma, Pedal Osteitis

Question Answer
what's a corn?Solar bruise at the angle of the bar and the wall (the quarter of the wall)
what is a bruise?rupture of blood vessels in the dermis under sole, frog, or hoof wall
Etiology of solar bruises?Trauma to the sole--> Rough/hard ground conditions, Pressure from improper shoeing, Poor confirmation (flat soles, under run heel with long toe)
Clinical Signs of solar bruises?Variable lameness (unilateral or bilateral), Focal areas of hemorrhage (Often obscured by pigmentation), Pain on palpation or hoof testers
how do you treat solar bruising?Remove source of trauma! Avoid hard surfaces, Appropriate trimming/ shoeing (Protect hoof from future trauma, Discourage excessive paring), NSAID's
what is Thrush? whats it look like?Pododermatitis of the frog- Degeneration of central and collateral sulci of frog, Necrotic, foul smelling debris
Etiology of thrush?Infection, Poor hygiene, Lack of hoof care and exercise, Conformation, sheared heels
what are the infections which can lead to thrush?(pododermatitis of the frog) Keratinolytic Bacteria: Fusobacterium necrophorum, Bacteroides spp.
Clinical Signs of thrush?Lameness is uncommon, Characteristic odor, Undermined frog
how do you treat thrush?Improve hygiene, Debridement
What is canker?Hypertrophic moist dermatitis of the frog and heel bulbs
etiology of canker?Idiopathic, Excessively wet conditions
treatment for canker?Debridement, Antiseptics
clinical signs of canker?Caseous, white exudate, Vegetative growth of frog corium, Sensitive tissues swollen and bleed easily, Variable lameness
prognosis for canker?poor, recurrent, progressive
what is a Keratoma?Tumor of keratin-producing cells
etiology of keratoma?idiopathic, chronic irritation
clinical signs of keratoma?Lameness is variable, Distortion of hoof capsule
what is the main problem a keratoma presents?it is a Space occupying lesion which causes Pressure necrosis of distal phalanx
prognosis of keratoma?Varies with size and location of lesion/ Pathologic fracture of P3
tx for keratoma?Surgical excision, Stabilize hoof wall
what is Pedal Osteitis? what does it lead to/cause?Inflammation of distal phalanx... Remodeling/ Lysis of solar margin
etiology of pedal osteitis?Chronic inflammation of laminae, Concussion, Sole bruising, Thin sole, Mild laminitis
clinical signs of pedal osteitis?Lameness variable: worse on hard surface. Pain on hoof testers
Pedal Osteitis diagnosis?Radiography shows Irregular solar margin and a Proliferative dorsal surface
how do you tx pedal osteitis?Eliminate primary problem, Rest, Protect sole from concussion, Work on softer surfaces, Appropriate shoeing (increase surface area)--> MAKE SURE shoe is balanced- stress on coffin bone (P3)