Flexural Limb Deformities Flashcards
How are FLDs named?
Named for the joint involved, not the tendon inovlved
FLDs affect what tissue?
Soft tissues
What joints are primarily affected by congenital FLDs 0-1mo of age?
Carpus, metacarpophalangeal region
What joints are primarily affected by FLDs acquired at 1-6 mo of age?
Metacarpphalangeal region, prox interphalangeal region
What joints are most commonly affected by congenital FLD?
MCP and carpi
What age do congenital FLDs present?
1st month of age
What causes congenital FLDs?
In-utero malpositioning, disease of mare during pregnancy
What diseases of the mare during pregnancy can cause FLDs?
Goiters, sudan grass ingestion, influenza
What are congenital FLDs?
Digital hyperextension, ruptured CDET
Caused by flaccidity of flexor muscles
Digital hyperextension
What is the most common congenital FLD?
Digital hyperextension
Attempting to bear weight but unable to keep toes on the ground
Digital hyperextension
What are sequential risks assoc w/digital hyperextension?
Skin/heel bulb ulceration
How do you treat digital hyperextension?
Light bandage
What is contraindicated for treating digital hyperextension?
Splints and thick bandages
Why are splints and thick bandages contraindicated for digital hyperflexion?
Relaxes soft tissue by taking weight/work off of them
How do you treat digital hyperextension?
Controlled exercise, NSAIDs, Oxytetracycline
How can farriery help treat digital hyperextension?
Palmar/plantar hoof extensions
Swelling @ dorsal fetlock is associated w/which congenital FLD?
Ruptured CDE
How will a congenital FLD stand?
Wt-bearing w/o full carpal extension or cannot bear weight at all
How do you treat the side effects of chronic NSAID use?
Omeprazole
Why do you need to dilute the oxytetracycline to 3g/00mL saline?
Nephrotoxic in hypovolemic animals
When should oxytetracycline be administered to help treat FLDs?
1-2x in the first 2-4wk of life
Inhibits contraction of collagen matrix and decreases MMP1 expression
Oxytetracycline
Prevents myofibroblasts from remodeling the collagen matrix of the affected tendon
Oxytetracycline
When splinting/casting an FLD, which joints should be incorporated and which should not?
NO NORMAL JOINTS in the splint
How can farriery protect toe from extensive wear assoc. w/FLDs?
Toe extension
Other than toe protection, how does a toe extension help correct FLDs?
Stress applied on DDFT to stretch it
When surgery is required, it is most commonly performed on which joint?
Carpus
What ligaments do you transect to correct a congenital carpal FLD?
FCU and ulnaris lateralis
Knuckling over fetlocks; can be enough that the foal stands on dorsal aspect of pastern
Ruptured CDET
Swelling over dorsal aspect of carpus
Ruptured CDET
Is there a surgical remedy for a ruptured CDET?
No
How do you manage a ruptured CDET?
Stall confinement and splint to avoid stumbling
Which joints to acquired FLDs most often affect>
MCP and DIP joints
What is the pathogenesis of acquired FLDs?
Mismatch in bone and tendon/lig growth
At what age do acquired FLDs present?
Between 1-4 mo and then @ yearling age
What are factors that predispose to acquired FLDs?
Pain (most commonly) and nutrition
How does excessive energy intake result in FLDs?
Rapid growth causes growth mismatch
Most cells in the DDFT and ALDDFT are _____
Myofibroblasts
How does pain cause an FLD?
Lack of use –> lack of elongation
When are you most likely to see and FLD at the DIP?
Between 1-4 months of age
Is DIP FLD usually unilateral or bilateral?
Bilateral
What is the main clinical sign of a DIP FLD?
Boxy hoof
What are components of boxy hoof?
Increased vertical dorsal hoof wall angle, overgrown heels
What does boxy hoof predispose to?
Subsolar abscesses
How does a functional shortening of the DDFT unit cause DIP FLD?
Excessive tension on P3 rotates it palmarly
Dorsal hoof wall angle >60* but <90*
Stage 1
Dorsal hoof wall >90* but <115*
Stage 2
Dorsal hoof wall >115*
Stage 3
Dorsal hoof wall doesn’t cross the vertical plane
Stage 1
What non-surgical ways can you manage acquired FLD?
Controlled exercise, NSAIDs, casts/splints
What farriery techniques can you use to manage acquired FLD?
Toe extension
What surgical procedure can you do for a stage 1 DIP FLD?
ICLD
What surgical procedure can you do for a stage 2 DIP FLD?
ICLD or DDFT if ICLD doesn’t work
What surgical procedure can you do for a stage 3 DIP FLD?
DDFT
Which DIP FLD sx procedure preserves athletic career?
ICLD
What ligament do you cut for an ALDDFT desmotomy (ICLD)?
Inferior check ligament
What is the success rate of an ICLD for horses <1 year old? >1 year old?
<1 = 90% success >1 = 80% success
Which breed does not recover well from ICLD if more than 8 months old? What is the success rate in this breed?
Standardbred 60% success if >8mo old
What is the easier location to perform a DDFT tenotomy on a horse?
Mid-metacarpus
Which DDFT tenotomy approach accesses the DFTS?
Mid-pastern
When do FLDs at MCP/MTP usually present?
Between 6-18 mo old
Is an FLD in the MCP or MTP more common?
MCP
What causes FLD in the MCP/MTP?
Prolonged non-weight bearing (short SDFT)
What are clinical signs of MCP/MTP FLD?
Upright pastern, knuckling over at fetlock
MCP joint more straight but still <180*
Mild
MCP joint at 180* but corrected when horse walks
Moderate
MCP joint >180* and does not correct when horse walks
Severe
Taut extensor tendons that are prominent enough to be seen on the dorsal aspect of the foot indicate what disease?
MCP/MTP FLD
How do you treat MCP/MTP FLD non-surgically?
Controlled exercise, splints
How do you “exercise” and MCP/MTP FLD horse?
“Hopping” - lift contralateral limb and lead horse to walk
What farriery techniques can you use to treat MCP/MTP FLD?
Raise heels w/wedge pads, toe extension
What surgeries can you do to manage MCP/MTP FLD?
ALDDFT or ALSDFT desmotomy (or both)
Which surgical technique is used for more severe MCP/MTP FLD?
ALSDFT desmotomy
Superior check lig desmotomy that lengtherns the SDF unit and extends the fetlock
ALSDFT desmotomy
