Equine Flash Notes - Lower Leg Lameness Flashcards
what are some other common names for dorsal metacarpal disease in horses?
bucked shins, shin splints,
what is the number one cause of lameness in 2-year-old race horses in their first training season?
bucked shins - dorsal metacarpal disease
too much too soon
what are the lesions seen with dorsal metacarpal disease?
periostitis & subperiosteal hematomas on dorsal metacarpal 3 - microfractures seen usually on dorsomedial aspect 2/3 of the way down the cannon bone
what are the causes of bucked shins?
concussion when the bone is not fully conditioned
stress on the dorsomedial surface which leads to an increase in thickness to compensate
is stress is faster than repairs, you get microfractures & subperiosteal hematoma formation
what is seen in horses with resolved cases of bucked shins?
new bone growth without pain
what is the classic case presentation of bucked shins?
acutely lame/pointing, short stride, increases with exercise, shuffling forelimb gait, & warm painful swelling on dorsomedial surface of MC3
what are the big differentials to consider for bucked shins?
fissure/saucer fractures of dorsal cannon
condylar fractures of MC3
soft tissue injury
what is the best view to diagnose bucked shins radiographically?
dorsomedial oblique - to highlight the dorsomedial surface
what is seen on rads that supports bucked shins?
acutely negative but with time will see subperiosteal lysis & subperiosteal callus formation
microfractures of the dorsomedial cortex of the bone
repeat rads in 7-10 days
how are bucked shins diagnosed?
clinical signs/age, palpation of dorsomedial aspect of MC3, acute pain/swelling, rads, & scintigraphy for bone scan
what treatment is used for all cases of bucked shins? what is used for mild cases? what about severe cases?
all cases - rest, controlled exercise program, & ice it if heat is felt
mild cases - 10-14 days of rest, controlled exercise program (hand walking, slow to moderate training), phenylbutazone, & topical DMSO painted on area SID/BID for 5-10 days to reduce inflammation
severe - convalescence for 1-3 months
what is the prognosis for bucked shins?
mild cases - good
severe cases - guarded, some may never get better, others take a year or more to become sound
how are bucked shins prevented?
deliberate controlled exercise programs!!!
90 days of galloping before speed work!!!
what are some predisposing factors to splints in horses?
excessive exercise when young, faulty conformation (bench knees where the medial splint bone is offset laterally & takes more weight or base narrow with the toe out which causes interference), improper nutrition (overweight)
what is the pathophysiology of splints in horses?
interosseous ligament can get torn due to stress
periosteal reaction occurs
medial splints due to stress & articulates with C2 & C3
what horses are often affected by splints?
young horses (~2 years old) in heavy training - affects the forelimbs, splint bones, on the medial side between MC2/MC3 where the interosseous ligament connects the splints to the cannon bone
what is the common acute presentation of splints? what about chronic?
acute - variable lameness that is most pronounced after work with swelling on the medial side of the metacarpus
chronic - blemish, more commonly seen!!! bony protuberance & lameness disappears
what are the sequela to splints in horses?
blind splint - swelling on the inside (axial) of the splint where you can’t see it
suspensory desmitis - encroachment on the suspensory ligament
how is acute splints diagnosed?
palpate pain/deep palpation & confirm with a local block or deep branch of the lateral palmar nerve
how is chronic splints diagnosed?
no pain palpated, bony swelling about 3 inches below the carpus
what is seen on radiology with chronic splints?
DLO view to look through interosseous space
osteolysis between MC2/MC3, osteoperostitis, dystrophic mineralization of the interosseous ligament
need to check in carpal joints are involved or if there is palmar extension to effect the suspensory ligament
what is the treatment for acute splints? what about chronic?
acute - complete rest for 7-10 days, bandaging to decrease swelling, cold hosing, NSAIDS, & no steroids!!!!!
chronic - if the bony prominence is impinging on the suspensory ligament or a cosmetic issue, can excise periosteum & bony growth with a pressure bandage 2 weeks after surgery & a light bandage another 2 weeks, & NSAIDS to reduce swelling and new bone formation but POSSIBLE RECURRENCE
what is the prognosis of splints?
good for athletes & cosmetic blemishes
guarded if it causes suspensory desmitis
what are some differentials for splints?
splint fractures
periostitis from interference
suspensory ligament strain
soft tissue trauma to metacarpus
what is the lay term for tendinitis?
bowed tendons
what is the number one site of tendon/ligament injury/strain in horses?
middle of the metacarpus
what are some predisposing factors to tendon/ligament injuries in horses?
racing (flat or steeple chase), fast, hard track»_space;> muddy track, inadequate training (highest incidence in 1st 3-4 racing starts), muscle fatigue, bad conformation with excessive pastern slop, & long toes
T/F: tendon/ligament strain/injury very commonly reoccurs in horses
true
how are tendon/ligament injuries in horses diagnosed?
history, clinical signs, & pain on palpation
ultrasound - necessary for treatment & prognosis
swelling/thickening of digital tendons
core lesion - anechoic area severe, black area
diffuse lesion
or localized to SDFT, DDFT, or suspensory ligament