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341 Cards in this Set
- Front
- Back
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what is the most common cause of lameness in the horse?
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subsolar abscess/"gravel"
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what causes the abscess in a subsolar abscess, and why does this cause lameness?
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- superficial infection of the sole corium
- lameness results from inflammation and pressure of a closed cavity infection |
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what is "gravel"?
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subsolar abscess
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what are three etiologies of subsolar abscesses/"gravel"
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1. migration of dirt/bacteria up the white line
2. superficial puncture wounds 3. horseshoe nails |
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what are five clinical signs of subsolar abscesses in the horse?
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1. mild-severe lameness
2. strong digital pulse in the affected limb 3. ± pain at coronary band or heels 4. ± swelling of the pastern region 5. ± drainage at coronary band or heels |
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what are two important ways (other than clinical signs) to diagnose a subsolar abscess?
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1. hoof testers to localize the area
2. careful exam of the white line and sole; if there are black tracts, that do not pare out, they will lead to the abscess |
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how is a sole abscess ("gravels") treated?
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- throughout, horse should be maintained in a clean, dry stall.
1. clean foot 2. open abscess without damaging corium (may find: dirt, watery black, or yellow pus) 3. soak in Epsom salts for 15-30 minutes, following by water-proof bandaging once per day for 3-5 days 4. bandage without soaking for 3-5 days 5. padded horseshoe with an antiseptic barrier dressing 6. TETANUS vaccine and phenylbutazone (judicious use) |
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what are four differentials for subsolar abscesses?
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1. sole bruise
2. coffin bone fracture 3. deep puncture wound 4. laminitis |
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how should you respond to a horse having a deep puncture wound?
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it is an emergency and prognosis depends on early diagnosis and aggressive treatment
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what eight structures could be involved in a deep puncture wound of the equine foot?
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- dermis (corium)
- distal phalanx - digital cushion - DDFT - navicular bursa - navicular bone - distal interphalangeal joint |
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what are six potential sequelae to a deep puncture wound of the equine foot?
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1. osteomyelitis
2. fracture 3. cellulitis 4. septic navicular bursitis 5. septic tenosynovitis 6. septic arthritis |
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what is an important clinical sign of a deep puncture wound?
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acute severe lameness
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if a foreign body is present in a deep puncture wound, what should you do before removing it?
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radiograph, at least 2 views
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if no foreign body is present, and you suspect a deep puncture wound of the foot, what should you do?
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- hoof testers to localize the area
- thoroughly pare the sole/frog to ID the puncture tract - use a blunt probe to determine the depth and direction of puncture and radiograph with probe in place - contrast fistulograms may also be helpful |
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if you don't have advanced facilities to treat a deep puncture wound of the foot, what should you do?
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referral
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after you have diagnosed a deep puncture wound in the horse and before you refer or continue to treat, what should you give to the horse?
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tetanus vaccine
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what are the three basic steps in treating a deep puncture wound of the foot?
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1. expose and debride affected tissues
2. samples for culture/sensitivity testing 3. long-term antimicrobial therapy |
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how do you treat a deep puncture wound of the foot that results in digital cushion cellulitis?
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1. sharp scalpel excision of the involved tissue
2. submit samples for culture/sensitivity 3. daily soaking/bandaging |
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how do you treat a deep puncture wound of the foot that results in osteomyelitis of the distal phalanx?
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1. remove abnormal bone by curettage
2. submit samples for culture/sensitivity 3. long-term antimicrobial therapy 4. bandaging |
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describe the process of treating a deep puncture wound of the foot that involves the DDFT/navicular bursa/navicular bone?
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1. remove central 2/3rd of the frog by sharp excision, extending through the digital cushion, to expose the DDFT
2. excise tendon areas of discoloration 3. remove, by curettage, any abnormal cartilage of the navicular bone 4. submit samples for culture/sensitivity 5. flush the navicular bursa thoroughly 6. sample fluid of coffin joint for c/s testing and determine of coffin joint leaks into navicular bursa by distending with saline 7. long term antimicrobial therapy 8. bandaging |
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where do horses with navicular disease experience pain?
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in the palmar aspect of the foot
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what type of structure is the navicular bursa?
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it is synovial
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what structures alone, or in combination may be involved in navicular disease?
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1. navicular bone
2. navicular bursa 3. apposing surface of the DDFT 4. navicular ligaments |
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what disease has a very similar pathogenesis to navicular disease?
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osteoarthritis of diarthrodial joints; this is because the navicular bursa is a synovial structure
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what two structures make up the wall of the navicular bursa?
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1. DDFT
2. navicular bone |
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what are two pathogeneses of navicular disease?
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1. distal conformation is normal, but ABNORMAL LOADS are applied to the navicular region
2. Applied loads are reasonable, but CONFORMATION IS INFERIOR, resulting in abnormal loading of the navicular region |
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what are four examples of abnormal loads that may predispose a horse to navicular disease?
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1. overuse
2. erratic use 3. work on hard ground 4. obesity |
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what are four examples of inferior conformation that may predispose a horse to navicular disease?
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1. upright pasterns
2. broken back hoof-pastern axes 3. under-run heels 4. small feet/body size |
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describe the most common form of lameness found in navicular disease
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almost exclusively forelimbs, usually bilateral, with a progressive onset
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describe the gait, during a lameness exam, of a horse with navicular disease
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- short, choppy gait
- lameness exacerbated by worn on hard ground and in tight circles |
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how is navicular disease diagnosed on a physical exam?
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1. HX/clinical signs
2. lameness exam 3. they resent hoof tester pressure over the navicular region 4. lameness improved by blocking the palmar digital nerves |
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what are three imaging techniques used to diagnose navicular disease?
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1. radiography
2. scintigraphy 3. MRI |
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comment on the "changes" seen in the navicular bone when using radiography to diagnose navicular disease
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1. "changes" seen in radiography may be clinically normal
2. absence of "changes" does not rule out the disease |
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when is scintigraphy most useful in diagnosing navicular disease?
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when radiographic changes are equivocal or not present
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what imaging technique provides the most specific diagnosis of navicular disease?
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MRI
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what factors affect the prognosis of treating navicular disease?
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- timing (stage of pathology)
- horse's conformation - expectations for the horse |
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what are the four main goals of treating navicular disease in the horse?
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1. allow damaged tissue to repair/heal
2. reduce stress/strain on navicular region 3. retard degenerative processes in the navicular bursa 4. improve navicular bone microcirculation |
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what are four ways to treat navicular disease
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1. trimming/shoeing to protect navicular region
2. rest/controlled exercise 3. medical Rx 4. neurectomy |
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failure of the connective tissue bond between the inner hoof wall and the coffin bone is called what?
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laminitis
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what is the definition of laminitis in the horse?
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failure of the connective tissue bond between the inner hoof wall
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what is required of the dermis for the growing hoof wall to precisely move past the stationary distal phalanx?
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regulation of matrix metalloproteinase activity by the laminar basal cells
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in laminitis, what exactly is inflamed?
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the lamellae
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describe the pathogenesis of laminitis in the horse
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- separation between the epidermal and dermal lamellae
- specifically, dyshesion between the epidermal basal cells and the basement membrane - compromised blood flow through the foot - severe pain that is uncontrollable |
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what are five common causes of laminitis in the horse?
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1. carb overload (pasture, grain)
2. GI disturbances (colic, diarrhea) 3. septic conditions (retained placenta, pleuropneumonia) 4. endocrine and metabolic abnormalities (Cushings, insulin resistance, obesity) 5. excessive unilateral weight bearing |
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what are the #1 and #2 causes of laminitis
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1. pasture (54%)
2. grain overload (8%) |
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what is an example of a mechanism of grain overload laminitis?
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1. excess carbs
2. bacterial overgrowth → low intraluminal pH 3. acidic environment kills other bacteria and damages intestinal mucosal barrier 4. "trigger factors" (e.g. endotoxins, exotoxins) enter the circulation and travel to the foot 5. the "trigger factors" disrupt normal MMP activity → laminitis |
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microanatomically, what determines the severity of clinical signs associated with laminitis?
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the amount of laminar damage
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what are four possible sequelae to laminitis?
- with no lameness or distal phalanx involvement - with lameness, but without distal phalanx involvement - with lameness and distal phalanx involvement (2) |
- with no lameness or distal phalanx involvement: hoof wall separation
- with lameness, but without distal phalanx involvement: hoof wall separation - with lameness and distal phalanx involvement: distal rotation or vertical displacement of the distal phalanx |
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what is the common name for laminitis?
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founder
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which feet are most severely affected by laminitis?
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front
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how should you respond to a horse having fulminant laminitis? Sub-clinical laminitis?
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both should be treated as an emergency and prognosis depends on early diagnosis and aggressive treatment
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what are the four goals in managing laminitis
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1. prevention
2. relieve the weight supporting demand on the inflamed lamellae 3. control of inflammation and pain 4. preserve blood flow through the laminar vasculature |
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fracture of forelimb P3 clinical signs
- grade of lameness? - other clinical signs? |
- Grade 3/5 lameness
- ↑ digital pulse, ± coffin joint effusion |
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how is a forelimb P3 fracture diagnosed?
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1. positive to hoof testers
2. radiographs |
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what complicates the radiographic diagnosis of a forelimb P3 fracture?
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fracture line may not show up for 10-14 days
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what are three methods to treat a forelimb P3 fracture that depend on the fracture location and type?
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1. immobilization/cast
2. lag screws 3. removal of bone fragment |
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what are two options to treat a fracture of the extensor process of forelimb P3 (a type 4 fracture)?
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1. if it is a large fracture, repair it
2. if it is a chip fracture, remove it |
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what are two big determinants of the prognosis of a forelimb P3 fracture?
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1. extent of articular involvement
2. presence of sepsis |
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if a horse is still lame after repair of a forelimb P3 fracture, what is a surgical option to correct the pain?
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palmar digital neurectomy
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what is the most common cause of a forelimb P2 fracture?
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sudden stops and turns on the supported leg
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what three ways is a forelimb P2 fracture diagnosed?
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1. Hx of sudden acute lameness
2. PE 3. radiographs |
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describe the first aid of a P2 forelimb fracture
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- bandage with a splint: straighten fetlock and keep it from moving
- walk on toe - Refer |
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what is the most common way that forelimb P2 fractures are treated?
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arthrodesis with PIP
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comment on the prognosis of a forelimb P2 fracture with:
- involvement of the DIP joint - with arthrodesis of the PIP joint - with conservative management |
- involvement if DIP joint: guarded
- with arthrodesis of PIP joint: good - conservative management: poor |
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what are the two most common presentations of a forelimb P2 fracture?
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1. biaxial palmar eminence
2. comminuted |
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what is the most common presentation of a forelimb P1 fracture?
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sagittal plane, initiated from the fetlock joint; can be complete, incomplete and/or comminuted
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describe the first aid of a P1 forelimb fracture
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- bandage with a splint: straighten fetlock and keep it from moving
- walk on toe - Refer |
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what is the major problem with a severely comminuted fracture of the forelimb P1? How is it treated.
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- there may be no intact strut of bone to bear weight
- need internal and external fixation - transfixation cast |
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what is the most common etiology of a forelimb P1 fracture?
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high speed injury
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what is the most common clinical sign of a forelimb P1 fracture?
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acute lameness
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comment on the clinical signs associated with a less severe, incomplete fracture of P1
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- lameness may be more subtle
- fetlock effusion |
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what is the prognosis, after surgery of the following fractures of the forelimb P1:
- No intact strut - Incomplete - Non-displaced - Pastern joint involvement - Complete fracture that exits lateral cortex - Non-comminuted |
- No intact strut: poor
- Incomplete: excellent - Non-displaced: excellent - Pastern joint involvement: fair/guarded - Complete fracture that exits lateral cortex: excellent - Non-comminuted: excellent |
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what is the most common location of a forelimb MC3 fracture? What are two others?
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- condylar fracture is most common
1. diaphyseal 2. Salter-Harris |
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what is the most common etiology of a condylar fracture of the forelimb MC3?
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high speed injury
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which condyle is most commonly fractured in the forelimb MC3?
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lateral
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how is a condylar fracture of the forelimb MC3 diagnosed?
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- acute severe lameness
- radiographs |
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what are four common types of fractures on the lateral condyle of the forelimb MC3?
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1. Sagittal plane
2. Incomplete 3. Complete/nondisplaced 4. Complete/Displaced |
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what are three common types of fractures on the medial condyle of the forelimb MC3?
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1. Short
2. Spiral 3. Y-fracture |
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fracture of which condyle of the forelimb MC3 is at risk of the most complications?
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medial
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describe the first aid of a condylar MC3 forelimb fracture
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- bandage with a splint: straighten fetlock and keep it from moving
- medial fracture: splint all the way up the leg - walk on toe - Refer |
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what is the most ideal way to treat a MC3 forelimb condylar fracture?
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internal fixation
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what types of MC3 forelimb condylar fractures can be treated with conservative management? What are two caveats?
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- incomplete or non-displaced lateral condylar fracture can be treated with conservative care
1. they have a good prognosis for pasture soundness, but not necessarily performance 2. delayed healing at the articular surface |
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comment on the prognosis of MC3 forelimb condylar fractures characterized by the following:
- medial condyle - lateral with internal fixation - with concurrent injury (e.g. sesamoid fracture or comminuted at joint surface) - lateral non-displaced fracture |
- medial condyle: fair
- lateral with internal fixation: good - with concurrent injury (e.g. sesamoid fracture or comminuted at joint surface): poor - lateral non-displaced fracture: good |
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what is required for a repair of a diaphyseal fracture of the forelimb MC3?
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internal fixation
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comment on first aid for a diaphyseal fracture of the forelimb MC3
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Full limb splint – stabilize joint above and below the fracture – sole can be on the ground
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what are two things that can complicate a diaphyseal fracture of the forelimb MC3?
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1. minimal soft tissue coverage (for closure)
2. comminution |
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what is the most common type of Salter-Harris fracture of the forelimb MC3 in foals? What parts of the joint are involved in this type of fracture?
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- Salter-Harris Type II
- fracture travels through growth plate and extends into metaphysis |
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how is a Salter-Harris fracture of the forelimb MC3 in foals treated? What is the prognosis?
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- internal fixation
- good prognosis |
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comment on the weight-bearing of the splint bones in the forelimb
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- the medial splint bone (MC2) bears the direct weight of C2
- the lateral splint bone (MC4) shares weight bearing of C4 with MC3 |
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where along the splint bones of the forelimb do most fractures happen?
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the distal 1/3rd
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how is a fracture of the distal 1/3rd of the splint bone of the forelimb treated? Why?
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- surgical removal
- May respond to conservative care – but highly mobile and may exacerbate desmitis causing continued lameness |
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what is a common sequela to a fracture of the distal 1/3rd of the splint bone of the forelimb?
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suspensory branch desmitis
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what determines the prognosis of a fracture to the distal 1/3rd of the splint bone of the forelimb?
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the amount of desmitis to the suspensory ligament and its branch
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comment on the first aid when you diagnose a fracture of the distal 1/3rd of a splint bone of the forelimb
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- heavy bandage
- usually need referral, but not an emergency - consider antibiotics based on etiology |
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when is removal of the entire splint bone of the forelimb indicated, when it has been fractured?
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in proximal fractures of MC4
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why don't you typically remove the medial splint bone of the forelimb in its entirety if it has been fractured?
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because it bears the full weight of the C2 bone
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what is the most common way to treat a proximal fracture of a forelimb splint bone?
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internal fixation
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which type of horses most commonly suffer from fractured proximal sesamoid bones of the forelimb?
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racehorses
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what is the most common fracture of the proximal sesamoid bones of the forelimb?
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apical
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what is the common sequela to a fracture of the proximal sesamoid bones of the forelimb?
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suspensory ligament desmitis
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when is a proximal sesamoid bone repaired by
- arthroscopic removal? - repair (internal fixation)? - arthrodesis? |
- removal: if fragment < 1/3rd of the bone
- repair if midbody - arthrodesis if bilateral |
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what are two treatments for arthritis of the forelimb, based on severity?
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1. conservative care usually suffices
2. if you cannot control pain, arthrodesis |
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what is the common name for coffin joint arthritis?
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low ring bone
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what is "low ring bone"?
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arthritis of the coffin joint
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comment on treatment of coffin joint arthritis (low ring bone)
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- once conservative management no longer works, arthrodesis is very difficult
- during treatment, good farriery is essential |
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what is the common name for pastern joint arthritis?
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high ring bone
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what is "high ring bone"?
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arthritis of the pastern joint
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comment on the prognosis of arthrodesis of pastern joint arthritis (high ring bone)
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since it is a low mobility joint, it is very good and the horse can be athletic
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what are "green osselets"?
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thickened periarticular structures – joint capsule, etc., associated with fetlock arthritis
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what is palmar metacarpal disease, who is affected by it, and what is the prognosis?
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it is an osteoarthritic stress remodeling of the trochleae in the fetlock joint, commonly seen in racehorses, which is career-ending
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what is the most common pathological lesion of OCD in the distal forelimb?
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osseous cyst-like lesions
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comment on the treatment and prognosis of osseous, cyst-like lesions in OCD of the distal forelimb
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- if OCD, needs treatment: debridement, steroids, other
- usually progresses to DJD |
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osteochondral chip fractures in the distal forelimb:
- recommended treatment - why is this treatment recommended? - etiology - most common location in the distal forelimb |
- Recommend surgical removal - arthroscopy
- When left in situ -- DJD will result - Usually a result of trauma - Rare in pastern joint |
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what is a common chip fracture of the distal forelimb in sport horses?
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dorsal P1 eminence fracture
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what is a common chip fracture of the distal forelimb in Standardbred horses?
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proximo-palmar P1 chip fracture
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what is a keratoma?
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a benign tumor of the horn of the hoof, which can be a space-occupying mass that causes pressure necrosis of P3, lameness, and recurrent abscess
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how is a keratoma treated?
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debridement of the hoof wall and necrotic tissue
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what is the common name for dorsal metacarpal disease?
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bucked shins
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what are "bucked shins"?
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dorsal metacarpal disease: in racehorses, swelling of the dorsal aspect of the forelimb MC3
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what are some clinical signs associated with dorsal metacarpal disease ("bucked shins")?
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- acute onset
- pain on palpation - choppy gait - usually bilateral |
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what is the pathogenesis of bucked shins?
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- stress-induced bone remodeling of dorsal MC3
- remodeling is maladaptive (not fast enough) - associated with young horses, early in training, when bone is growing |
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what are three ways to prevent bucked shins?
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1. decrease distance of runs
2. increasing frequency of short interval, high-speed work 3. soft surfaces (grass) as opposed to hard surfaces |
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what is osteostyxis?
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drilling holes in bone to expose cortex to medullary blood supply; speeds healing
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what can happen if bucked shins are not treated?
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can progress to a distal cortical stress fracture
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which splint bone is most likely to pop and why?
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MC2 because it is weight-bearing
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what is a bench knee? What is a common acquired injury that relates to this condition?
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a congenital defect where the knee (carpus) is not centered over the cannon bone. Can lead to popped splints.
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how are popped splints treated?
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- Rest
- Anti-inflammatories - Rarely surgery |
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what are the three joints of the carpus? How many carpal bones are there?
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1. radiocarpal joint
2. intercarpal joint (middle carpal) 3. carpometacarpal joint - 7 carpal bones |
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which carpal bone is most susceptible to chip fracture?
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distal radiocarpal bone
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in which horses are carpal bone fractures most common?
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racehorses
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which carpal joints communicate?
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intercarpal (middle carpal) and carpometacarpal joint
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what causes chip fractures in the carpus?
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they are secondary to stress-induced subchondral bone sclerosis
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how are carpal chip fractures treated?
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arthroscopic removal
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what is a common fracture of the carpus in racehorses that requires screw fixation and sometimes, joint reconstruction?
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C3 slab fracture
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what is the cause of a C3 slab fracture in the racehorse?
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stress remodeling that is maladaptive
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what is carpal canal syndrome?
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swelling of the carpal sheath
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what are some causes of carpal canal syndrome?
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- DDFT lesion
- distal radial exostosis (i.e. osteochondroma) |
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what can cause a subtle lameness of the shoulder, characterized by a clubby foot, resentment to shoulder flexion, that responds to an IA block of the glenohumeral joint?
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bone cyst
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comment on treatment of shoulder fractures
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- some have surgical options
- conservative care → DJD and usually severe lameness |
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name four musculoskeletal injuries/disorders that are commonly found in the equine shoulder
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1. bone cyst
2. shoulder fracture 3. bicipital bursitis 4. shoulder osteoarthritis |
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what is a sequela that is associated with a radial fracture in the horse?
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laminitis
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what is the most common reason for an ulnar fracture in the horse?
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trauma associated with halter breaking young animals
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what are two clinical signs of an ulnar fracture in the horse?
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1. acute non-weight-bearing lameness
2. unable to straighten the carpus |
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comment on the first aid for an ulnar fracture
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full limb bandage with a caudal splint
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comment on the prognosis of ulnar fractures
- with internal fixation - with conservative management - that are articular |
- most have good prognosis with internal fixation
- conservative management good for non-displaced, non articular fractures - articular fractures have a lower prognosis for soundness |
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comment on the prognosis of a humeral fracture in the horse
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poor
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what is a paratenon? What parts of the tendon lack it?
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- an exogenous source of BV and cells for a tendon to heal
- tendon sheathes do not have a paratenon (e.g. the DDFT sheath) |
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what are the three phases of a tendon's response to injury?
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1. Inflammatory phase - Vascular and cellular
2. Repair phase - Fibroblasts; Intrinsic & extrinsic repair 3. Remodeling phase |
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what two physical properties of a tendon are compromised after healing is complete?
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1. decreased tensile strength
2. decreased elasticity |
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what part of a tendon, if injured, will heal most slowly and why?
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Lesions within synovial sheaths are slower to heal than those outside a sheath. This is thought to be related to the lack of a paratenon within the sheath. The paratenon, and the endotenon, serves as a source of new blood vessels and cellular elements for repair.
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if you suspect a tendon injury, what are you looking for on palpation?
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Heat, pain, swelling, consistency
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how do you best palpate a tendon when you suspect injury?
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palpate the tendons when the horse is weight bearing on the limb, and when the limb is picked up
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when palpating a tendon for injury, why do you want to palpate it when the limb is picked up (in addition to when weight bearing)?
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Picking the limb up allows you to more easily separate the SDF and DDF tendons during palpation. It also makes palpation of the origin of the suspensory easier.
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what are two things that you must do when performing an ultrasound examination of an equine limb?
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1. must do both transverse and longitudinal views
2. must ultrasound the contralateral limb, as tendonitis is often bilateral |
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what is a Type 1 tendon lesion?
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slightly less echogenic than normal, with minimal disruption in fiber pattern
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what is a Type 2 tendon lesion?
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lesion is described as ½ normal and ½ anechoic, this represents fiber disruption with
some local inflammation |
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what is a Type 3 tendon lesion?
|
lesion is mostly anechoic and represents significant fiber tearing
|
|
|
what is a Type 4 tendon lesion?
|
lesion is completely anechoic, represents complete fiber disruption
|
|
|
slightly less echogenic than normal, with minimal disruption in fiber pattern is what Type of a tendon lesion?
|
Type 1
|
|
|
lesion is described as ½ normal and ½ anechoic, this represents fiber disruption with
some local inflammation is what Type of a tendon lesion? |
Type 2
|
|
|
lesion is mostly anechoic and represents significant fiber tearing is what Type of a tendon lesion?
|
Type 3
|
|
|
lesion is completely anechoic, represents complete fiber disruption is what Type of a tendon lesion?
|
Type 4
|
|
|
what are three reasons why tendonitis is problematic after resolution?
|
1. Tendon is slow to heal
2. Healed tendon lacks elasticity and strength 3. High incidence of recurrence |
|
|
what are three basic ways to control inflammation associated with tendonitis?
|
1. Anti-inflammatories
2. Support bandage 3. Cold therapy |
|
|
controlling inflammation associated with tendonitis using support bandages:
- how does it reduce inflammation? - what do you do in severe cases? |
- During the acute phase the application of compression bandages reduces edema and inflammation by increasing interstitial hydrostatic pressure.
- In more severe cases of injury the use of palmar/plantar splints or casts may be warranted. In the most severe cases where all support is lost, then full-limb casts may be necessary. |
|
|
controlling inflammation associated with tendonitis using cold therapy:
- how does it reduce inflammation? - comment on the use of ice packs - what is the maximum time it should be performed and why? |
- During the acute phase of inflammation, cold therapy has both an anti-inflammatory and an analgesic effect. This happens through vasoconstriction, a decrease in local enzymatic activity, a reduction in the formation of inflammatory mediators, and decreased nerve conduction rates.
- Cold hydrotherapy is known to be better than the use of ice packs because of an increase area of contact. - Cold therapy should not be performed for longer than 30 minutes at a time due to reflex vasodilation that will actually increase edema and inflammation. |
|
|
what is the purpose of prolonged, strict exercise protocols in the resolution of tendonitis?
|
reduce scar tissue formation, resolve residual inflammation, maintain gliding function of the tendon, promote optimal collagen production
|
|
|
what are the four components in tissue regeneration of tendonitis?
|
1. Scaffold
2. Cells 3. Cytokines 4. Growth Factors |
|
|
what are five fancy substances that you can inject into a tendon to promote healing?
|
1. urinary bladder matrix
2. autologous bone marrow 3. bone marrow derived stem cells 4. adipose derived stem cells 5. platelet rich plasma |
|
|
what are two benefits and 2 problems associated with injecting autologous bone marrow into a damaged tendon?
|
- benefits: multipotent stem cells → fibroblasts; very high levels of growth factors
- problems: low number of stem cells, so you need a large volume to get enough of them; contains high TGF-β1, which can promote excessive scar tissue |
|
|
what is an advantage to using bone marrow-derived stem cells to treat tendonitis? A disadvantage?
|
- advantage: pure stem cells → less volume to inject
- disadvantage: 2-4 week delay and $$$ |
|
|
what are four advantages of using adipose-derived stem cells over bone marrow or bone marrow derived stem cells?
|
1 – minimal morbidity associated with collection
2 – clinically relevant number of cells from a single collection without need for cell culture 3 – higher frequency of stem cells than in bone marrow (2% vs. 0.002%) 4 – higher cell proliferation rates (in vitro) |
|
|
what does platelet rich plasma contain that may help tendonitis?
|
- fibrin matrix
- growth factors |
|
|
comment on using shock wave therapy to treat tendonitis
|
Biological effect is dependent on the energy delivered and the number of shocks administered. Excessive energy damages tissues. Some more recent literature demonstrated that there was no long-term difference between ESWT patients versus controls.
|
|
|
what is a surgical approach to treating SDFT injury in the forelimb? How does it work?
|
- superior check ligament desmotomy
- Purpose is to lengthen the musculotendinous unit of the SDFT, however it actually increases the strain on the SDFT due to increased extension of fetlock joint. |
|
|
what is a complication of superior check ligament desmotomy in thoroughbred racehorses?
|
suspensory ligament injury
|
|
|
what is a procedure, formally used to relieve chronic tendon injuries, that is now only used to prevent compartment syndrome?
|
percutaneous tendon splitting
|
|
|
what are the four forms of tenosynovitis?
|
1. idiopathic
2. acute 3. "complex" (Chronic) 4. infectious |
|
|
what are the three most common causes of tenosynovitis in the horse?
|
1. accumulative low-grade microtrauma associated with normal exercise
2. direct trauma (overreach injuries) 3. abnormal forces outside the normal range of motion (hyperextension) |
|
|
what are the three ultrasonographic stages of tenosynovitis?
|
1 – symmetrical effusion without evidence of synovial proliferation
2 – more pronounced, often asymmetrical, effusion of the proximal pouch & is accompanied by synovial proliferation 3 – significant synovial proliferation, adhesion formation, and the presence of synovial masses |
|
|
what are four types of "complex" (Chronic) tenosynovitis in the horse?
|
1. Tenosynovial masses
2. Digital sheath fibrosis 3. Adhesions 4. Annular ligament constriction |
|
|
what is the common initial treatment for idiopathic or acute tenosynovitis? What is the initial treatment for "complex" (chronic) tenosynovitis?
|
- acute/idiopathic: intrathecal corticosteroids and systemic NSAIDs
- complex: hyaluronic acid and steroids |
|
|
why is septic tenosynovitis an emergency?
|
It is important to remember where the digital flexor tendon sheath is located. It begins approximately 2/3 of the way down the cannon bone, and ends at approximately mid-P2. Septic tenosynovitis can be the result of lacerations anywhere between these 2 points, but can also occur secondary to puncture wounds to the sole of the foot.
|
|
|
how do you treat septic tenosynovitis medically?
|
- Stall rest
- Bandage - NSAIDs - Antibiotics (Parenteral, regional) |
|
|
how do you treat septic tenosynovitis surgically?
|
- Lavage, debridement & drainage
- Wound repair - Annular ligament transection |
|
|
what will the foot look like when the SDFT is lacerated?
|
Fetlock dropped
|
|
|
what will the foot look like when the SDFT and DDFT are lacerated?
|
- Fetlock dropped
- Toe off ground |
|
|
what will the foot look like when the SDFT, DDFT, and the suspensory ligament are lacerated?
|
- Fetlock all the way on the ground
- Toe off ground |
|
|
comment on the prognosis of an extensor tendon laceration versus a flexor tendon laceration.
|
- extensors: > 75% sound
- flexors: 84% survival; 45-82% sound (worse) |
|
|
what type of collagen comprises a normal tendon? What type is made when it heals?
|
- normal: Type I
- healed: Type III |
|
|
how do you interpret a negative result on a c/s testing for septic tenosynovitis?
|
discard the data; it is negative 50% of the time. Only a positive result is significant.
|
|
|
what three enzymes do you look for in serum chemistry of the horse with muscle disease and where do they originate?
|
1. CK – found mainly in skeletal muscle, cardiac muscle, and brain tissue (not readily exchanged between CSF and plasma)
2. AST – found mainly in skeletal muscle, liver, and heart 3. LDH – found in most tissues including muscle, thus is not muscle specific, RBC’s contain large amounts of LDH, thus hemolyzed samples provide falsely elevated LDH |
|
|
what is an important cause of electrolyte loss that may lead to rhabdomyolysis in the horse?
|
sweating
|
|
|
what is nuclear scintigraphy?
|
Injection of a radioisotope (for muscle/tendon/bone: labeled phosphates), which seem to only be taken up in areas of ongoing damage, and not in areas of repair. Imaged with a gamma camera.
|
|
|
what is an Exercise-Response test?
|
Exercise Response Test - Measure serum CK levels before exercise (15 minutes of trotting – must be a hard trot since intensity is important) followed by serum CK levels at 4 to 6 hours. This submaximal exercise test will detect subclinical rhabdomyolysis. Normal = less than 3-4 fold increase in CK. Confounding factors include the fitness levels of the animal, as more fit patients may have no change in enzyme levels following exercise. Can also measure AST, but it has a slower rise, thus levels may remain normal following submaximal exercise.
|
|
|
what is electromyography?
|
Evaluates the entire motor unit (ventral motor horn cell, its axon, axon terminals,
neuromuscular junctions, and the muscle fibers innervated). |
|
|
with a suspected muscle disorder, what are three things to do on PE?
|
1. assess muscle symmetry
2. palpate muscles 3. observe the horse at walk, trot, ± under saddle |
|
|
what are five things to look for when you palpate a muscle?
|
1. heat
2. pain 3. swelling 4. atrophy 5. fibrosis |
|
|
what is the fancy name for "tying up"?
|
exertional rhabdomyolysis
|
|
|
what are the two basic classifications of exertional rhabdomyolysis
|
1. sporadic
2. chronic |
|
|
describe sporadic exertional rhabdomyolysis: how often does it occur? What is its occurrence associated with?
|
- singe or infrequent episodes
- in conjugation with exercise |
|
|
describe chronic exertional rhabdomyolysis: how often does it occur? What is its occurrence associated with?
|
- repeated episodes
- mild or no exertion - may be heritable (PSSM, RER) |
|
|
what is the main difference between sporadic and chronic exertional rhabdomyolysis?
|
CER has an underlying myopathy that causes the repeated episodes, while SER is truly due to an overexertion during exercise.
|
|
|
what are five causes of sporadic exertional rhabdomyolysis
|
1. Sudden increase in exercise
2. Exercise after 1 or more days of rest while on full feed 3. Training or management changes 4. Endurance horses (High body temp, Fluid losses and electrolyte imbalances, Depletion of muscle energy stores) 5. Associated with respiratory infection |
|
|
recurrent equine rhabdomyolysis:
- breeds affected - pathological mechanism - what triggers it? - signalment for the most severely affected horses |
- TB, SB, Arabians
- disorder of intracellular calcium regulation - triggered by excitement - nervous 2-year-old fillies in race training most severely affected |
|
|
that are two other forms of chronic exertional rhabdomyolysis other than the recurrent form that involves defective intracellular calcium regulation?
|
Two other “forms” of CER include PSSM in quarter horses (mainly) and EPSM in draft horses.
|
|
|
what are a crap-ton of clinical signs associated with exertional rhabdomyolysis?
|
- Anxious, sweating
- Stiff, stilted gait - Increased HR, RR - Most commonly hindquarters - Pain on deep palpation - Marked muscle definition, cramping - Painful, reluctant to move, recumbent - Movement may exacerbate signs - Myoglobinuria - Colic, renal damage |
|
|
describe the lab results for sporadic exertional rhabdomyolysis
|
muscles enzymes 10-1000X greater than normal, depletion in NA, K, Cl, dehydration,
metabolic alkalosis |
|
|
describe the lab results for chronic exertional rhabdomyolysis
|
can have subclinical disease where no clinical signs are seen, but CK can reach levels up to 10,000 U/L, CK will usually peak 4-6 hours after exercise, many lab results (electrolytes, hydration status, pH) may be normal as CER is NOT due to exertion during exercise
|
|
|
how is exertional rhabdomyolysis treated?
|
- STALL REST
- Analgesia (butorphanol) - NSAIDs - Hay diet/No grain - Restore fluid/electrolyte, acid/base balance - Acepromazine - IV DMSO |
|
|
comment on the fluid therapy in the treatment of exertional rhabdomyolysis
- route of administration - electrolytes - acid/base |
- Fluid therapy may be performed either with IV or enteral fluids.
- Remember these are usually hypokalemic so must supplement K until the horse is eating again. - Bicarb therapy is usually not needed as acid-base balance will usually self correct following rehydration. |
|
|
why must you be careful when administering NSAIDs to a horse with exertional rhabdomyolysis?
|
because they are dehydrated
|
|
|
what is an easy and effective procedure to help relieve the horse of some pain from exertional rhabdomyolysis
|
cold water or alcohol baths
|
|
|
what are four physical ways to prevent exertional rhabdomyolysis?
|
1. Standardized daily routine
2. Minimize stress in environment 3. Daily exercise 4. Long, slow warm-up period |
|
|
what are five nutritional ways to prevent exertional rhabdomyolysis?
|
1. high quality grass hay
2. minimize carbs (low starch, high fat) 3. Vitamin E 4. Electrolyte supplement 5. decrease grain intake on days when not being exercised |
|
|
in which cases of exertional rhabdomyolysis is electrolyte supplementation usually used?
|
sporadic (not chronic)
|
|
|
what are three pharmaceutical ways to prevent exertional rhabdomyolysis?
|
1. low dose acepromazine before exercise (calms the nerves)
2. dantrolene (decreases Ca release) 3. phenytoin (decrease Ca release) |
|
|
what is PSSM?
|
an inherited glycogen storage disorder characterized by the abnormal accumulation of glycogen, abnormal polysaccharides, and elevated levels of G6P.
|
|
|
what is the big difference between exertional rhabdomyolysis and PSSM/EPSM?
|
In comparison to equine rhabdomyolysis, PSSM/EPSM is a disease due to abnormal accumulation of polysaccharide, NOT a calcium disorder.
|
|
|
what are some clinical signs of PSSM?
|
- muscle stiffness
- Reluctance to exercise - Reluctance to move - exercise intolerance - Overt muscle - History of ER or poor performance - muscle atrophy, renal failure, severe Colic-like Pain |
|
|
what are three histopath findings of PSSM on muscle biopsy?
|
1. Subsarcolemmal vacuoles
2. Periodic acid-Schiff (PAS) positive 3. Resistance to amylase digestion |
|
|
what gene is mutated in horses with PSSM?
|
GYS1 (glycogen synthase 1)
|
|
|
how do you treat PSSM?
|
- Dietary changes: (High fat, Low starch, High fiber)
- High fat sources of calories (Introduce slowly, Corn oil, rice bran, Commercial feeds) - Daily exercise |
|
|
after surgery, when the horse appears awake enough to stand but continues to make unsuccessful attempts, what do might they have?
|
Post-Anesthetic myopathy
|
|
|
post-anesthetic myopathy:
- which muscle group is unilateral? - which muscle groups are bilateral? - besides the above, how else can it manifest? - what causes it? - when does it happen? - how is it treated? |
- unilateral: triceps
- bilateral: gluteals, longissimus - can be generalized - result of hyperperfusion - it can be immediate or delayed - treat as you would for exertional rhabdomyolysis |
|
|
what other disease that occurs in pigs is similar to, but not the same disease as post-anesthetic myopathy in horses?
|
malignant hyperthermia
|
|
|
how is post-anesthetic myopathy prevented?
|
Prevention – adequate padding, proper limb support and positioning, maintain adequate BP (MAP of 80mmHg is ideal), prophylactic use of dantrolene in horses with history of myopathies
|
|
|
what is the prognosis of post-anesthetic myopathy?
|
Prognosis – depends on extent of muscle damage, horses often completely recover, but can develop significant fibrosis and atrophy. If severe enough, then euthanasia may be warranted.
|
|
|
hyperkalemic periodic paralysis:
- breeds - Mendelian genetics - what is the defect? |
- quarter horses descended from "Impressive"
- Autosomal dominant, not sex-linked, homozygotes are more severely affected - defective voltage-gated Na channels (hyperexcitable cell membrane) |
|
|
hyperkalemic periodic paralysis:
- signalment - between episodes, how do animals appear? - when do episodes occur? - how long do they last? |
- Signs evident by 2-3 years of age, well muscled
- Appear normal between episodes - Onset of clinical signs are unpredictable - Episodes last 15-60 minutes with variable frequency of recurrence |
|
|
what are some things that can trigger an episode of hyperkalemic periodic paralysis?
|
- Ingestion of high K diets (Alfalfa hay, molasses, electrolyte supplements, kelp-based products)
- Sudden dietary changes - Fasting - Anesthesia - Heavy sedation - Trailer rides - Stress |
|
|
what are the clinical signs of hyperkalemic periodic paralysis?
|
- Brief period of myotonia
- Prolapse of the third eyelid - Sweating and muscle fasciculations - Recumbency, dog sitting - Alert but unable to respond - ± Tachycardia - Dyspnea - Death during an episode - Normal afterward |
|
|
what test for hyperkalemic periodic paralysis is
- the best? - no longer recommended because it can be fatal? |
- DNA analysis
- KCl challenge test |
|
|
what are three emergency treatments of hyperkalemic periodic paralysis?
|
1. IV calcium gluconate
2. IV dextrose 3. tracheostomy with severe respiratory obstruction |
|
|
what drugs are contraindicated in horses with hyperkalemic periodic paralysis? Why?
|
glucocorticoids, because these drugs have been shown to induce episodes in humans with similar conditions.
|
|
|
what is the most important dietary nutrient for patients with hyperkalemic periodic paralysis?
|
potassium - you want to keep it low
|
|
|
how do you treat mild episodes of hyperkalemic periodic paralysis?
|
- Stall rest
- Hand walking - Grain meal or corn syrup orally (Stimulate insulin-mediated movement of K across cell membranes) - IM epinephrine - Acetazolamide (a carbonic anhydrase inhibitor; promotes K excretion in renal tubules) - Observe for worsening of signs - Many recover spontaneously |
|
|
comment on dietary prevention of hyperkalemic periodic paralysis
|
- Decrease dietary potassium
- NO Alfalfa hay, brome/ orchard grass hay, canola oil, soybean meal or oil, molasses - Timothy/bermuda grass hay (later cuts) - Regular, multiple small feedings - Adequate exercise (pasture ideal) |
|
|
what are two drugs used to reduce potassium in the prevention of hyperkalemic periodic paralysis?
|
1. acetazolamide (carbonic anhydrase inhibitor; promotes K excretion in renal tubules)
2. hydrochlorothiazide (K wasting diuretic) |
|
|
what is the prognosis for
- exertional rhabdomyolysis? - PSSM? - Hyperkalemic periodic paralysis? |
- Rhabdomyolysis: Fair to guarded with management
- PSSM: Good with proper management - HYPP: Good in the majority of cases; Severe cases may be fatal (homozygous); DO NOT BREED affected animals; Advise Vet before sedation/anesthesia |
|
|
which two musculotendinous ruptures in the horse?
|
1. gastrocnemius
2. peroneus tertius |
|
|
what are some causes of a gastrocnemius musculotendinous rupture?
|
- overextension of hock
- after flipping over backwards - has been reported in foals following first attempt to rise - after dystocia |
|
|
what are causes a peroneus tertius musculotendinous rupture?
|
occurs due to overextension of the hock with concurrent flexion of the stifle
|
|
|
what does the leg look like with a gastrocnemius musculotendinous rupture?
|
hock will appear excessively flexed (loss of extensor influence)
|
|
|
how do you diagnose a peroneus tertius musculotendinous rupture?
|
diagnosis is based on ability to extend the hock while flexing the stifle (avulsion injuries are often severely lame initially), horse may bear weight normally but the limb becomes flaccid when backed
|
|
|
how do you treat a gastrocnemius musculotendinous rupture?
|
if can bear weight then place on stall rest, if cannot bear weight then use either a sleeve cast or splints to stabilize the limb
|
|
|
how do you treat a peroneus tertius musculotendinous rupture?
|
avulsions are best evaluated arthroscopically, midbody ruptures are treated with 3 months of stall rest
|
|
|
where on the muscle does musculotendinous rupture of the peroneus tertius occur?
|
origin in foals and distal 1/3 of body in adults
|
|
|
what disease is characterized by an exaggerated flexion of the hindlimb?
|
stringhalt
|
|
|
what are two causes of stringhalt?
|
1. neurogenic
2. dandelions (outbreaks in Australia) |
|
|
how is stringhalt treated surgically?
|
Lateral Digital Extensor Myotenectomy
|
|
|
what is fibrotic myopathy?
|
fibrosis of the semitendinosus muscle, resulting from trauma or stringhalt, characterized by a gait where the horse swings its hindlimb inward
|
|
|
how is fibrotic myopathy treated surgically?
|
Semitendinosus tenectomy - cut the PROXIMAL insertion
|
|
|
what is the key clinical sign for hyperkalemic periodic paralysis?
|
sitting like a dog
|
|
|
what is the most common cause of fibrotic myopathy?
|
trauma due to trailer accident
|
|
|
why does exertional rhabdomyolysis cause renal injury?
|
- myoglobin is toxic to the kidneys
- electrolyte imbalance |
|
|
why must you be sure to rehydrate the horse with exertional rhabdomyolysis before administering NSAIDs?
|
because electrolyte imbalance, myoglobin, and the NSAIDs can all contribute to renal damage
|
|
|
what is the risk of pulling the limb forward (during surgery) to reduce pressure on the radial nerve?
|
it can cause post-anesthetic myopathy of the triceps muscles
|
|
|
what are three goals of initial treatment of a fracture site?
|
- Prevent damage to vascular and neural structures
- Prevent conversion to an open fracture or Prevent further contamination of open fractures - Minimize further damage to bone ends and soft tissues |
|
|
what are three goals of initial treatment of the patient after it has undergone a fracture?
|
- Relieve anxiety associated with unstable limb
- Able to ambulate onto trailer - Survive transport to hospital |
|
|
if a fracture patient is in CV shock, what sedative should you avoid and why?
|
acepromazine, because it causes hypotension
|
|
|
which sedative causes the least ataxia?
|
romifidine
|
|
|
what are three things that cause fluid losses in the fracture patient?
|
1. hemorrhage (uncommon; associated with nasal, frontal, sinus fractures; large vessel laceration)
2. sweating 3. maldistribution |
|
|
what are four other derangements that may be present secondary to a traumatic fracture?
|
1. damaged nerves
2. other muscles and bones injured 3. infection 4. pain |
|
|
in the fracture patient, when is the most appropriate time to take radiographs?
|
AFTER stabilizing. Note: do not compromise the fracture for the sake of radiographs
|
|
|
comment on pros and cons of distal versus proximal fractures
|
- distal: easier to stabilize and fix
- proximal: more muscle mass support; more complicated fixation |
|
|
what "doubles the cost and halves the prognosis" of an equine fracture?
|
infection
|
|
|
what is a "break down" injury?
|
anything that disrupts the suspensory apparatus
|
|
|
comment on the adult versus foal fracture patient
|
ADULTS:
- Can be more fractious - Panic - lost stability - Physical restraint more challenging - Chemical restraint / Twitch FOALS: - Smaller mass - More manageable: Can lie down, Physical restraint, Easier transport - Calm the dam! - Improved prognosis |
|
|
what is the most important thing to do when communicating with a client regarding their horse's fracture?
|
step away from the horse so they pay attention to you instead of the horse
|
|
|
what type of tape should you use to secure a splint?
|
non-elastic tape such as duct tape
|
|
|
what are three common mistakes when stabilizing a fracture for transport?
|
- Splints too low
- Inadequate support (e.g. Broom handles) - Rushed job |
|
|
what is zone 1 of stabilization of fractures?
|
- Coronary band to distal MC/MT; Includes: P1, P2, sesamoids, distal MCIII, suspensory
|
|
|
what is zone 2 of stabilization for fractures in the forelimb and hindlimb?
|
- forelimb: distal MC to distal radius
- hindlimb: distal MT to tarsus |
|
|
what is zone 3 of stabilization for fractures in the forelimb and hindlimb?
|
- forelimb: distal radius to elbow
- hindlimb: tarsus to stifle |
|
|
what is zone 4 of stabilization for fractures in the forelimb and hindlimb?
|
- forelimb: elbow and proximally
- hindlimb: stifle and proximally |
|
|
what is a Kimzey splint?
|
splint that stabilizes the fetlock and encircles the hoof so that the horse walks on its toe.
|
|
|
how do you stabilize a forelimb zone 1 fracture?
|
- Align dorsal cortices
- Thin padding - dorsal splint - Toe up to proximal MC - Kimzey splint |
|
|
how do you stabilize a hindlimb zone 1 fracture?
|
- Reciprocal apparatus precludes aligning bones in straight line
- Plantar splint - Toe up to calcanean tuber |
|
|
how do you stabilize a forelimb zone 2 fracture?
|
- Thick Robert Jones bandage
- Splint caudal and lateral - Splint ground to elbow |
|
|
how do you stabilize a hindlimb zone 2 fracture?
|
- Thinner bandage than on front limb
- Mid MT to calcanean tuber - Caudal + LATERAL splint |
|
|
how do you stabilize a forelimb zone 3 fracture?
|
- Thin tissue medially
- Bandage up to the chest - Splint to withers |
|
|
how do you stabilize a hindlimb zone 3 fracture?
|
- Reciprocal apparatus-can’t immobilize stifle
- Immobilize hock - Bandage to inguinal area - Splint to hip |
|
|
how do you stabilize a forelimb zone 4 fracture?
|
- Lateral muscle support
- Axial body wall support - Lost triceps (fractured ulna, humerus, or scapula) - Goal: Fix carpus for dropped elbow |
|
|
how do you stabilize a hindlimb zone 4 fracture?
|
- Lots of muscular support
- Stabilization not possible - Adequate muscle insertions distal to the fracture to allow control of the limb (Generally cannot bear weight) |
|
|
comment on the proper way to load an injured horse onto a trailer and transport
|
- Stabilize before loading
- Bring trailer to the horse - Load with injured limb to back of trailer (Acceleration easier to control than stopping) - Accelerate and brake slowly - Do not tie head - they need the head to balance - Use partitions, butt ropes, chest supports to secure the body |
|
|
how do you properly unload an injured horse from a trailer?
|
- Unload onto sound limbs (turn horse around in trailer)
- Provide secure footing - Reduce step if possible - Don’t rush!!! |
|
|
what is unique about the rear lateral splint bone with regards to injury to the suspensory ligament?
|
hindlimb MT4 has a larger head than MT2; causes the suspensory ligament to be encased in 3 areas of bone in the hindlimb. Desmitis: can't swell as much
|
|
|
what do you do with a vestigial MC1/MC5?
|
amputate
|
|
|
define the Types I - IV condylar fractures
|
Type I - incomplete
Type II - complete non-displaced Type III - complete displaced (Type Most common) Type IV - diaphyseal |
|
|
how are condylar fractures of the hindlimb treated?
|
internal fixation with lag screws
|
|
|
comment on communication of the tarsal joint sacs
|
the distal tarsal-metatarsal can communicate with the distal intertarsal, but not the other way around; there is a one-way valve
|
|
|
DJD of the tarsus is called what?
|
bone spavin
|
|
|
what joints are involved in bone spavin?
|
- TMT & DIT
- Tibiotarsal & PIT NOT involved |
|
|
what are three etiologies of bone spavin?
|
1. “Wear & Tear” – repeated compression & rotation
2. Sickle hocks (excessive curvature to hocks) 3. Upright hocks |
|
|
what is a characteristic gait of bone spavin?
|
they bring their legs in medially so it looks like they are walking on a tight-rope
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where are radiographic changes usually seen in bone spavin?
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osteophytes on the dorsomedial side of the tarsus
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which blocks are used to diagnose bone spavin?
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1. IA - tarsus
2. Tibial and Peroneal nerve blocks |
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what is the main therapeutic goal of bone spavin?
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pain relief and soundness, not cartilage preservation
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why do you not try to salvage a tarsus with bone spavin?
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• Low motion joints
• Slow disease progression • Joint fusion desirable |
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what are some ways to treat bone spavin medically?
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• ± “Corrective shoeing / trimming”
• NSAIDs • IA corticosteroids • Hyaluronic acid • PSGAG • Nutriceuticals • Continued work |
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what is the easiest surgical technique used to treat bone spavin?
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arthrodesis by injection of 70% ethanol into the tarsal joint
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if ethanol injection is not desired or doesn't work, what is another way to arthrodese the hock to treat bone spavin?
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articular drilling: drill across joint space to destroy cartilage
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what is the lay term for hock effusion?
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bog spavin
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what are some causes of bog spavin?
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• Idiopathic
• Synovitis/capsulitis • Conformation • Osteochondrosis • Fracture • Desmitis • Septic arthritis • PIT DJD |
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**what is the normal TP and WBC count of synovial fluid?
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- TP = < 2.0 g/dL
- WBC < 5,000 cells/μL |
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what are five ways to treat bog spavin?
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• Nothing
• Rest • IA medications (IRAP serum; Corticosteroids) •Arthroscopic surgery •Antimicrobials & lavage |
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what are four common locations of osteochondrosis of the tarsus?
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- Distal intermediate ridge of tibia
- Lateral trochlear ridge - Medial trochlear ridge - Medial / lateral malleoli |
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how is osteochondrosis of the hindlimb treated?
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arthroscopic removal
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what are the three synovial compartments of the stifle? Which ones communicate?
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1. Femoropatellar
2. Lateral femorotibial 3. Medial femorotibial - #1 and #3 communicate |
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what type of drug is most effective in OA of the stifle?
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corticosteroids
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what are five etiologies of osteochondrosis?
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1. Failure of endochondral ossification
2. Nutrition 3. Rapid growth / genetics 4. Trauma (subchondral bone cysts) 5. Copper deficiency (Collagen cross linking in subchondral bone) |
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where do osteochondral flap lesions of the stifle occur?
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on the proximal aspects of the medial and lateral trochlear ridges
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where do osteochondral bone cysts occur in the stifle?
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- Medial condyle
- Lateral condyle – very rare |
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comment on treatment of osteochondral bone cysts
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- debridement is no longer indicated
- now, use guided injection with a corticosteroid - in the future: stem cell injection |
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what causes intermittent upward patellar fixation?
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- “Catching the patella”
- Tight circles and fatigue - Poor conditioning |
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what is the appearance of a persistent upward patellar fixation?
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- Limb locked in extension
- Limb held to rear |
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what are two ways to treat intermittent upward patellar fixation?
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1. Modify training to condition quadriceps
2. Injection of counter-irritants (Inflammatory response causes thickening of the medial patellar ligament) |
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what are three ways to treat persistent upward patellar fixation?
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1. manipulation under sedation
2. medial patellar ligament splitting technique 3. medial patellar ligament desmotomy |
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what is the surgical technique of choice for a persistent upward patellar fixation?
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medial patellar ligament splitting
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what are 7 common sites fo horse cranial skull fractures?
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1. Mandible
2. Frontal bone 3. Zygomatic Process 4. Nasal bone 5. Supraorbital process 6. Cranial vault 7. Maxilla |
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what is the most common reason for a cranial vault fracture?
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flipping over backwards
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which bone in the cranial vault is most commonly fractured from flipping over backwards?
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basisphenoid
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what are five things that you look at/for with cranial fractures on a PE?
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1. MENTATION
2. Cranial Nerve Exam 3. Cerebral damage 4. Fracture depression that may not be obvious 5. Epistaxis and/or bleeding from ear |
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what are the two most important reasons to treat a horse with a cranial fracture medically?
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1. reduction of cerebral edema
2. control seizures |
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what are four findings of a frontal/nasal bone fracture on physical examination?
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- Epistaxis
- Bony Depression - SQ Emphysema - Skin lacerations |
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what are four goals of repairing a nasal/frontal bone fracture?
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- Restore normal facial contour
- Restore/maintain upper airway integrity - Resolve sinusitis - Resolve/prevent sequestration |
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what are two potential complications of frontal/nasal bone fractures?
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1. hemorrhage into sinus cavities
2. airway obstruction |
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why do you need to lavage blood out of a sinus if it has hemorrhaged due to fracture?
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because empyema will result if you do not
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what are three things you look for on physical exam evaluation of a zygomatic bone fracture?
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1. asymmetry
2. EVALUATE THE EYE (swelling, exophthalmos, proptosis) 3. epistaxis |
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what are four ocular complications of a zygomatic bone fracture?
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- Corneal ulcerations
- Anterior Uveitis - Rupture of the globe - Blindness |
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what are three ways to repair a zygomatic bone fracture?
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1. pull it back into place and see if it stays put
2. cerclage wiring 3. reconstructive plates |
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what is the most common bone fractured in the head of the horse?
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mandible
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what is quidding?
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dropping feed (associated with mandibular fracture)
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what are the two basic goals of surgical repair of a mandibular fracture?
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1. restore masticatory function
2. cosmetic appearance |
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how do you place a cerclage wire for a fracture of the incisive aspect of the mandible?
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go one tooth beyond the fracture on both sides and notch the back side of the canine tooth so the wire does not fall off
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how do you fix a fracture of the interdental space of the mandible?
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- wire the incisors and canine to the premolars
- internal fixation with screws - apply a PMMA protective coating |
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how do you repair a horizontal fracture of the ramus of the mandible?
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- use a plate that is bent to conform to the jaw contour
- screws need to be placed in between the tooth roots using fluoroscopy |
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how do you fix a fracture of the vertical aspect of the ramus of the mandible?
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- need to dissect masseter muscle
- use internal fixation with a plate and screws |
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for a complete (interdental) fracture of the mandible, how is it repaired?
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U-bar fixation
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how are fractures of the caudal aspect (premolar/molar) of the mandible repaired?
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Type II external fixation
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