Lameness Flashcards

Question

What is the problem with flexion tests?

Answer 1

\* not specific \* hard to interpret \* many sound horses have positive flexion tests

Answer 2

Cons: time consuming, understand limitations \*\* Regional vs. intra articular-- complications uncommon but still severe-- painful, more invasive, also don't know what we are blocking

Answer 3

Bigger nerves take longer to block-- tibial and peroneal e.g.

Answer 4

Test whether they have worked.... e.g. hoof testers, most horses hate you squeezing suspensory apparatus, skin sensation not a great taste-- we aren't checking the skin

Answer 5

\* In practice most common cause of lameness in race horses is carpal lameness... so more efficient

Answer 6

Sagittal ridge \* flap and fragment formation tend to occurs at the margin of weight bearing and non weight bearing areas \* the sagittal ridge of MC/MT3

Answer 7

flap and fragment formation tend to occurs at the margin of weight bearing and non weight bearing areas

Answer 8

flap and fragment formation tend to occurs at the margin of weight bearing and non weight bearing areas

Answer 9

flap and fragment formation tend to occurs at the margin of weight bearing and non weight bearing areas

Answer 10

Fragmentation-- distal intermediate ridge of the tibia in the tarsocrural joint

Answer 11

fetlock joint where fragmentation of the proximal plantar P1 fragments

Answer 12

Subchondral cysts tend to occur in weight bearing areas such as the medial condyle of the femur in the stifle

Answer 13

Subchondral cysts (weight bearing areas)

Answer 14

Subchondral cysts (weight bearing areas)

Answer 15

Proximal interphalangeal joint Subchondral cysts (weight bearing areas)

Answer 16

Middle 1/3rd of the MC has no tendon sheath \* Digital tendon sheath on the bottom

Answer 17

Okay to lose one, but more than one--\> Lose extensor function and start knuckling Remove one extensor tendon for stringhalt

Answer 18

A really deep one can involve all 3 lose the DDFT- Toe up the in air lose the suspensory ligament- fetlock sinking

Answer 19

Suture- clean simple transection only Special suture patterns-- locking loop, tendon pulley suture \*\* in practice rare to get a nice clean simple transection of the tendon Support: - extensor tendons-- bandage, simple splint, toe extension shoe - flexor tendons-- support bandage, rescue splint, cast, heel extension shoe, raised heel shoe

Answer 20

\* depends on extent of wound \* Open tendon sheaths heal well \* Stringhalt (causing exaggerated bending of the hock) occasional complication in hind limbs

Answer 21

\*\* Flexor tendons: tendon lacerations involving the tendon sheath: poorer prognosis, heal poorly, adhesions between tendon and surrounding sheath which can affect performance (reduced mobility of the leg)

Answer 22

\* proper diagnosis as early management improves prognosis

Answer 23

Palmar aspect of the fetlock-- digital tendon sheath likely involved

Answer 24

coffin joint (pastern?)

Answer 25

Carpal joint- have a feel to see if you can palpate the articular cartilage-- if you can feel a tendon, may be in the tendon sheath depending on anatomy-- or inject sterile fluid on the other side and if it comes out then you know you are in the joint

Answer 26

affecting navicular bursa

Answer 27

Digital sheath-- synovial structure

Answer 28

\* Aggressive early treatment will improve prognosis (more aggressive than if the joint was not involved) \* Open well draining wounds better than small puncture wounds-- often the little ones you have to worry more about then the big ugly open wound \* Debridement, lavage, broad spectrum antibiotics (penicillin + gentimycin), monitor carefully \*\* Casting will assist healing

Answer 29

Septic synovitis | (haematogenous in foals)

Answer 30

Severe lameness and swelling

Answer 31

Tarsocrural joint

Answer 32

Septic synovitis Echogenic fluid (normal synovial fluid is anechoic- black)

Answer 33

\* Culture- positive only in 50% of cases (because lots of means of synovial fluid to stop bacterial growth) \* Fluid directly into blood culture \*\* NO bacteria does not mean it is not infected!!!

Answer 34

IV antibiotics of the leg with a tourniquette \* Intra-articular to get very high levels and easier (systemic antibiotics: penicillin + gentamycin)

Answer 35

Fetlock Prognosis guarded due to infection and often develop OA

Answer 36

\* nerve blocks \* Diagnosis based on clinical examination and radiographs

Answer 37

\*\* scintigraphy won't be positive for a week because not yet increased osteoblastic activity

Answer 38

\* Analgesics, sedation (low dose), stabilise the leg

Answer 39

Cannon bone fracture

Answer 40

Helps prevent anxiety as well

Answer 41

Cannot be stabilised

Answer 42

Avascular necrosis-- wire has cut off the blood supply therefore delayed sloughing of tissue distal to the injury \* early diagnosis is challenging because they all have cold limbs, all have some vasoconstriction \*\* usually just treat and warn the owners \* Flow phase scintigraphy can help but generally wait and see

Answer 43

Provide supplements of calcium and phosphorous as well as vitamins A & D to counteract the reduced uptake of available calcium from the feed \* shifting intermittent lameness, failure of young horses to grow to expected height... advanced: fractures of pelvic bones, ribs and splint bones, spinal column collapse and hind limb in-coordination \*\* Big head-- swollen forehead, nasal and jaw bones, loose teeth, inability to chew food, distortion of the nose and noisy breathing due to restricted nasal passages

Answer 44

\* Lucerne hay or molasses

Answer 45

High serum phosphate antagonises serum Ca2+--\> low Ca2+ stimulates PTH--\> Ca2+ resorbed from bone--\>nutritional secondary hyperparathyroidism--\> osteodystrophia fibrosa e.g. big head in a pony or shifting lameness

Answer 46

\* Urinary P excretion... compare urein: serum % of phosphorous and creatinine (baseline metabolite that the kidney doesn't reabsorb)

Answer 47

\* Enough energy, protein, Ca, sunlight, Cu \* Ca: P balance especially with cereal supplements

Answer 48

1. Flap and fragment formation 2. Fragmentation alone 3. Subchondral bone cysts

Answer 49

Retained cartilage

Answer 50

Flap and fragment formation in OC

Answer 51

Lumped under OC because young growing horses at particular predilection sites

Answer 52

\* Swelling (except not in shoulder joint because covered in muscle)

Answer 53

\* swelling less obvious: medial FT joint swelling

Answer 54

Proximal limb lameness

Answer 55

suspect shoulder OCD

Answer 56

\* Restrict exercise \* Restrict diet \* Monitor radiographically

Answer 57

\* Removal of osteochondral fragments \* Debridement of subchondral cystic lesions

Answer 58

Stifle osteochondrosis swelling in a yearling, very common presentation (occasionally an older horse) \*\* can ID lateral because the medial has the big prominence where the stay apparatus hooks

Answer 59

has to be the tarsal crural joint because of the amount of swelling tarsal sheath never swells cranially

Answer 60

fragmentation of the distal lateral trochlear ridge

Answer 61

Ununited plantar eminence P1- fetlock osteochondrosis

Answer 62

end up lame because swelling isn't obvious enough early on

Answer 63

If corticosteroids do not work (once or twice)--\> surgical debridement (intra-articular, extra-articular.... arthrodesis)

Answer 64

Arthrodesis, also known as artificial ankylosis or syndesis, is the artificial induction of joint ossification between two bones by surgery. This is done to relieve intractable pain in a joint which cannot be managed by pain medication, splints, or other normally indicated treatments.

Answer 65

"proud flesh"- exuberant granulation tissue

Answer 66

\* Suture- rarely successful without casting \* open wound \* Most substances placed on wounds delay healing-- as little as possible \* Initially: reduce bacteria numbers, stimulate granulation tissue--\> debride and lavage \* When wound has granulated-- inhibit granulation tissue with pressure from a cast (bandage only provides pressure for a very short while) and topical corticosteroids (rub in 2 x daily), remove excessive granulation tissue (excise= cut it off, topical caustic substances- copper sulphate, which affects epithelialisation however)

Answer 67

\* Level granulation tissue bed required \* easily traumatised

Answer 68

Punch grafting easiest - donor site = neck - biopsy punch - immobilise limb

Answer 69

\* Complications - subcutaneous emphysema - elbow joint sepsis (avoid with penicillin and gentamycin instead of just penicillin, if elbow is involved) \*\* uncommon as nice open wounds that drain well

Answer 70

DIP= distal interphalangeal joint \* Difficult to determine extent of wound without surgical exploration \* field: sedate the horse, abaxial nerve blocks, if finger goes in more than a few centimeters-- then recommend sending the horse off

Answer 71

\* Debridement: under GA, extensive debridement of collateral cartilage \* debride and ligate digital vessels \* sharp sectioning of nerve (blunt sectioning could result with a neuroma) \* Synovial structures involved-- then inject sterile fluid at remote site to see if it comes out of the wound to see if it is involved-- if it does then you need to flush the synovial structure to remove foreign material + bacteria

Answer 72

\* Careful apposition \* large mattress sutures through skin and subcutaneous tissue

Answer 73

\* restriction of exercise e.g. confined to a yard

Answer 74

Quittor- infection of the collateral cartilages

Answer 75

Problem because not as open, important to determine which structures involved-- serious injuries: navicular bursa, DIP joint, digital sheath

Answer 76

\* Determine which structures are involved \* Careful trimming of sole/frog \* Radiograph- plain, sterile probe and take a radiograph, contrast material \* You can also try and collect synovial fluid to see if a synovial structure is involved-- if we can't collect fluid-- can put saline in and see if it runs out the hole

Answer 77

Pedal bone-- debride, curette pedal bone (healthy pedal bone is hard to remove, whereas unhealthy is soft) - bandage initially - hospital plate (keeps it dry and clean) \*\* once it has filled in with hard horn you can stop bandaging it

Answer 78

\* Good prognosis but healing is long

Answer 79

\* street nail procedure-- problem defect in DDFT resulting in serious complications \* Arthroscopic debridement is the modern treatment-- instrument through wound \* Broad spectrum antibiotics-- locally intrathecal, intravenous perfusion \* Elevate heel \* hospital plate

Answer 80

Expensive with guarded prognosis

Answer 81

Interosseous ligament aka suspensory ligament

Answer 82

\* Shape and symmetry \* Shoeing \* Pulse over the sesamoid bones- struggling to feel is what we want \* Coronary band-- injuries or swelling \* hoof testers- looking for a painful response, keep going and come back to it-- to ensure they aren't just playing up that there was actually focal pain \* hoof knife- clean it up to see defects, bruising \* Swelling around the pastern, sometimes even the fetlock can be associated with the foot as the foot can't swell \* most foot problems are worse on a hard surface

Answer 83

Nerve blocks

Answer 84

Don't want to block the pastern joint, problem is the local diffuses \* sole, heel, hoof capsule, etc.

Answer 85

Joint also blocks the palmar digital nerve, but you don't block the heel as you're not getting the branch

Answer 86

\* Radiography, ultrasonography, scintigraphy, MRI, CT, arthroscopy (pack sulci with playdo)

Answer 87

\* Standing lateromedial - foot on block - beam centered on solar surface of pedal bone - parallel to bulbs of the heels (since horse may stand toe in for example) \* Standing dorsopalmar - assessment of lateromedial balance \* Upright pedal bone - pedal bone exposure - navicular bone exposure \* Obliques- important for fractures \* Skyline navicular bone - assess flexor surface - corticomedullarly junction

Answer 88

\* determine significance of radiographic changes \* detect bone pathology not observed on RGs

Answer 89

\* Better definition of bone changes \* Contrast allows visualisation of blood flow in the foot

Answer 90

\* Coffin bone, P3, pedal bone

Answer 91

\*History: sudden onset usually not associated with work, severe lameness, distal limb swelling \* Exam: increased digital pulse, pain on hoof testers \* Diagnosis: positive palmar digical, abaxial sesamoid nerve block; no changes on radiographs (pus similar density to hoof wall, can see air but not pus), purulent material localised \*\* DDX: Fracture, acute subsolar bruise, synovial sepsis, laminitis \* Treatment: drain abscess, NSAIDs (pain relief), if unable to drain: poultice (softens the foot easier to work with next time, common thought that it helps drain the abscess by soaking up moisture but unlikely), reexamine... failure to improve? P3 osteitis, keratoma, synovial structure \*\* if they are not getting better and keep recurring: abscesses generally don't form next to the pedal bone-- should not keep reforming-- might be in the bone due to laminitis-- sometimes have to remove part of the bone to actually resolve the problem

Answer 92

Chronic bruising growing out in the picture \* HIstory: acute: sudden onset with work, no localising signs (may not see it at all if it has black feet); chronic- insidious onset/ recurring lameness, no localising signs \* Exam: often poor conformation-- thin flat soles, collapsed heels.... increased digital pulse due to chronic or acute inflammation in the foot, +/- pain on application of hoof testers \*\* Increase the sole depth to protect the bottom of the foot \* Diagnosis: positive response to palmar digital nerve block, no changes on radiograph, scintigraphy-- increased uptake of radiopharmaceutical at pedal bone solar margin

Answer 93

If it becomes really chronic and causes changes

Answer 94

Don't assume obvious swelling is the site of lameness Foot abscesses can result in swelling passing up limb Always perform nerve blocks if in doubt about source of lameness If lameness blocks to the foot remove the shoe, dress the foot and inspect carefully Foot lameness worse on a hard surface (whereas tendon lameness would be similar grade on hard and soft)

Answer 95

\* Breakdown of bond between hoof wall and laminae- basement membrane \* Pedal bone sinking \* Pedal bone rotation \* Compromised blood supply from pressure of the pedal bone

Answer 96

\* in ponies associated with - systemic disease \*\* lush pasture \*\* equine metabolic syndrome \*\* PPID

Answer 97

\* Increased digital pulse \* Tachycardia \* pain on hoof testers \* Lameness: quadralateral, bilateral forelimb, bilateral hindlimb (less common)... reluctant to move, leaning back, short stepping \* Indentation of coronary band (if pedal bone sinks or rotates) \* Chronic hoof changes (dropped sole, non-parallel rings)

Answer 98

\* sinking-- bigger gap between hoof wall and pedal bone \* gas lines- lamina is weak and breaks down \* pedal bone modelling, lysis

Answer 99

\* Acute - treat cause - prevent mediators accessing laminae (cold therapy, only effective early) - pain relief (NSAIDs-- phenylbutazone) - minimize P3 movement (restrict exercise- box confinement, deep bedding, sand, sole support, cast, DDF tenotomy)

Answer 100

\* Wedge to reduce tension on DDFT (dental impression material, high density foam)

Answer 101

\* generally collapsed sole around the tip of the pedal bone-- the most painful area when they bear weight on it \* Only trim if pedal bone is stable (if unstable and you try this, the horse will become more uncomfortable, so you can try trimming just a little): trim the sole from the point of the frog back and remove excess toe-- don't want to remove any of the sole in front of the frog because you want to protect the tip of the pedal bone with as much sole as possible \* improve blood flow to coronary band \* Remove necrotic tissue: pedal bone (debride, large amount can be removed successfully), laminae \* Shoeing-- only when pedal bone stable, elevate painful areas of sole \*\* Diet: maintenance, good quality feed, do not starve

Answer 102

\* how quickly the pedal bone stabilizes -- even with a lot of rotation, pedal bone can still stabilize

Answer 103

\* Degenerative condition of the flexor surface of the navicular bone \* difficult diagnosis

Answer 104

\* History: variable-- classic: gradual onset of bilateral forelimb lameness \* Exam: variable, uni or bilateral, foot conformation variable... often worse on lunge, worse on hard surface, flexion test positive

Answer 105

\* navicular bursa block- most specific block you can do \* Radiograph changes only seen when disease is advanced-- flexor surface skyline view \* Ultrasound- may observe bursa effusion (not that useful) \* Scintigraphy- increased uptake of radiopharmaceutical in navicular bone, non specific \* MRI- DDF tendon lesions, more sensitive for bone lesions \* Bursoscopy-- not usually for diagnosis but if you want to consider a procedure-- assess fibrocartilage, surface injury to DDF tendon

Answer 106

\* Pain is part of the pathogenesis-- do all we can do to remove pain-- NSAID... best way intra-thecal corticosteroids (not a cure), neurectomy (not a cure, not permanent-- lasts 6 months- 2 years but can break the pain cycle) \* Improve foot balance- lateromedial balance, move centre of pressure palmarly (length of the lever arm around the joint affects the load on the navicular bone-- so shifting center of pressure BACK) e.g. egg balance shoes \* Antiarthritic drugs (not a lot of evidence)- pentosan, isoxuprine (older therapy, vasodilator, evidence poor), bisphosphonates (boney resorption going on in the pedal bone, so people think this might help, but poor evidence for efficacy)

Answer 107

An injury may be on the pastern because it could be affecting the digital sheath which runs the whole way

Answer 108

\* Distal interphalangeal joint - dorsal coronary band \* Proximal interphalangeal joint - synovial distension rarely recognized - firm periarticular swelling common \* Distal palmar soft tissue structures - injury to flexor tendons results in swelling of digital sheath - distal sesamoidean ligaments rarely recognized

Answer 109

\* Pain on flexion-- positive flexion test \* often worse on a hard surface

Answer 110

\* worse on the lunge and hard surfaces Palmar digital nerve-- try to do it low enough that you avoid blocking the proximal interphalangeal joint (will block DIP joint and it does block PIP joing a lot) \* Intra-articular nerve blocks another possibility-- DIP and PIP- not as specific \* Radiography-- lateromedial, dorsopalmar, flexed oblique \* Ultrasound-- useful for palmar soft tissue structures-- always indicated with digital sheath swelling, more difficult in metacarpal area.... collateral ligaments of both PIP and DIP \* Scintigraphy useful for stress fractures-- esp P1 or OA

Answer 111

collateral ligament injury of DIP joint \*\* collateral ligament attaches to P2 and P3 BUT two problems

Answer 112

PIP joint diagnosis: - local analgesia - radiographs-- unreliable unless condition is advanced, ID of fractures, cysts is helpful; scintigraphy \* TX: intra-articular medication, arthrodesis

Answer 113

Swelling palmar aspect, pain on deep palpation \* Ultrasound

Answer 114

High motion joint-- need analgesia, x-rays are not all that helpful even with advanced lesions. You do not always get swelling e.g. severe OA with no swelling

Answer 115

\* May be none \* Differentiate joint and digital sheath \* Suspensory branch desmitis (palpate to localise swelling and pain)

Answer 116

Pain on flexion, positive flexion test (not specific of course as could be pastern) \* Diagnosis-- Abaxial: may block sesamoids; low 4 point - intraarticular- via collateral ligament of sesamoid another option - Radiography: lateromedial, dorsopalmar elevate 10 degrees, obliques-- elevate 10 degrees forelimbs-- elevate 35 degrees hindlimbs, flexed lateromedial, highlight plantar aspect of condyle- elevated oblique, dorsopalmar with leg forward \*\*\* radiography can have no radiographic changes - Ultrasound- suspensory ligament branches -- synovium- dorsal synovial pad -- digital sheath- annular ligament, flexor tendons - Scintigraphy -- subchondral bone injury -- increased uptake in lateral condyle of hind fetlock normal in race horses

Answer 117

Subchondral bone injury

Answer 118

\* area of condyle that articulates with sesamoid \* subchondral bone modelling in response to training

Answer 119

subchondral bone injury under electron microscopy \* 1st one is normal horse \* 2nd is race horse \* 3 subchondral bone \* 4 resting for weeks turning over subchondral bone start off with subchondral bone cartilage--\> collapse of underlying subchondral bone--\> cartilage erosion--\> secondary degenerative changes

Answer 120

\* Local analgesia-- plantar metatarsal nerve block \*\* SCINTIGRAPHY BETTER THAN XRAY-- diagnostic in combination with nerve block (MRI is good for diagnosis shows lysis in white-- darker area is sclerosis)

Answer 121

\* Minimum of 3 months rest \* Most horses will race again but at a lower level of performance \* poor prognosis if recurs or if you can see changes on radiograph

Answer 122

\*Swelling - tarsocrural joint - tarsal sheath - calcaneal bursa - extra-synovial \* Pain on flexion - only severe inflammatory disease or injury \* Flexion test: not specific, fetlock and stifle problems often positive

Answer 123

\* Regional blocks - subtarsal block - tibial and peroneal \* Intra-articular blocks - Tarsometatarsal joint - Centrodistal joint - Tarsocrural joint (not usually necessary because obvious and swells a lot) \* Radiography-- minimum of 4 views (lateromedial, dorsopalmar, dorsolateral plantaromedial oblique, dorsomedial plantarolateral oblique)... special views-- skyline of calcaneus, flexed lateromedial \* Ultrasound-- assessment of tendons and ligaments, determining involvement of synovial structures, locating osteochondral fragments \* Scintigraphy- must combine with local analgesic techniques, OA of distal tarsal joints, subchondral bone injuries

Answer 124

\* tarsal sheath is overtly infected-- lots of swelling all over the place not just over the tarsal sheath ... kick broken the skin, damaged the bone, after 7 days enough lysis that we have a bony lesion under the sheath-- big problem.... debrided this... \* Multiple synovial structures \* Radiographs unreliable for distal joints

Answer 125

\* Examine for swelling: - femoropatellar joint - medial femortibial joint \* Palpate patellar ligaments \* Flexion test- may have pain on flexion

Answer 126

\* Intra-articular injection of all 3 compartments at once \* Radiography-- lateromedial, flexed lateromedial, caudaocranial, flexed skyline view of patellar \* U/S- patellar ligaments, abaxial aspects of menisci, femortibial joints for effusion \* Scintigraphy-- complex appearance, poor access to medial aspect \* Arthroscopy- articular cartilage, cruciate ligaments, menisci and meniscal ligaments

Answer 127

Stifle osteochondrosis

Answer 128

Stifle osteochondrosis

Answer 129

\* however if it has been going on for a long time you will get muscle atrophy... examine pelvic symmetry \* Rectal exam e.g. haematomas with acute fractures \* Diagnostic analgesia: Sacroiliac joint, sacroiliac ligaments \* Radiography-- need GA \* U/S- assessment of ligaments and muscles, bony surface of pelvis \* Scintigraphy- pelvic fractures, hip joints \*\* Bottom line: difficult to assess clinically... easily examined rectally and ultrasound... some acetabular fractures you need to go to x-ray

Answer 130

\* Does not necessarily fit foot abscess because it hasn't improved over 4 weeks \* You might also worry about stress fracture of the condylar, split P1 (vertical fracture common in race horses) \* Nerve block could be dangerous if it is a stress fracture but it is 4 weeks later so probably not \* Pedal bone fracture

Answer 131

Acidosis- SI is not able to digest all of the starch--\> getting through to the caecum--\> bacterial overgrowth producing lactic acid--\> osmotic effect producing watery diarrhoea \* acidity could wear away the mucosa and allow toxins into the blood stream \*\* bacteria can change a thousand fold in a few hours \*\* bacteria fermenting the starch in the hindgut and growing-- it is not those toxins that will cause the horse to be sick, it will be the endotoxic from the gram negative bacteria that will wear away the endothelial lining and allow the endotoxin into the blood stream

Answer 132

\* you can give them hay to keep things moving along \* if it just happened, you could try virginiamycin but unlikely to help because it would come behind the start

Answer 133

Classic laminitic stance

Answer 134

\*\* laminae are supporting the whole weight of the horse --\> severe laminitis pulling apart of the dermis from the epidermis and rotation of the pedal bone

Answer 135

Basement membrane is the glue that holds the epidermis to the dermis \*\* all about the epithelial cells and their attachment to the basement membrane and what causes them to pull apart \*caused by inflammation (gram negative endotoxins-- sepsis/ septicaemia type situation) and enzyme activation-- epithelial cells secrete enzymes normally but if they secrete excess it chews away the membrane

Answer 136

Acute laminitis

Answer 137

\*First Aim: STABILISE: Support the frog-- relieving loading on the toe (glue on shoes or styrofoam pads and duct tape, deep sand optimal surface) \* Icing the feet - effects on blood flow - prevents reperfusion injury - inhibition of enzymes \* Anti-inflammatories/ analgesics - e.g. phenylbutazone - Novel analgesics (gabapentin) \* Vasodilators - ACE promazine (out of favor these days) \* matrix metalloproteinase (MMP) inhibitors - none currently available

Answer 138

\*\* these cases tend not to over rotate \* can be managed

Answer 139

Equine Metabolic Syndrome \* High amounts of sugar \* fructan carbs are the storage type of carbs \* Stimulate insulin response-- it is actually insulin that causes laminitis in this situation \* Ponies; some horse breeds \* insulin dysregulation \* obesity \* Abnormal fat deposition- nuchal ligament \* Laminitis predisposition

Answer 140

\* bred to survive in harsh conditions... metabolically extremely efficient (storing fat well, etc.)

Answer 141

\* ponies and andalusians were getting a massive swing in insulin

Answer 142

Insulin \*\* high concentrations will trigger laminitis but mechanisms are unknown-- causes the epithelial cells to proliferate and letting go of the membrane

Answer 143

\* Weight loss: can soak hay to leach out water soluble carbohydrates... OR poor quality hay (but with mineral supplement then) & EXERCISE \* analgesics and NSAID's \* Will be okay in a few days... but it will be a recurring problem if the animal is on grass... a lot of work. \*\* grazing muzzle- can still get to grass but less \* OR restricted access to grazing (dirt yard) \* Low GI diet-- no grain

Answer 144

Hyperlipaemia--massive mobilization of fats that overwhelms the liver.... if they suddenly go into a negative energy balance 1.25- 1.5 % bwt (DM)/ day + exercise once laminitis is resolved

Answer 145

\* Correct orientation of hoof capsule in relation to distal phalanx (P3) \* Allow well bonded lamellae to grow down from coronary band region

Answer 146

Horse carpal valgus

Answer 147

Horses are inefficient coolers-- rely on evap from sweat Heat from contracting muscle conducted to the skin by the blood-- fluid evaps on the skin and removes heat from the body \*\* lose a lot of electrolytes in their sweat

Answer 148

\* nutritional- vitamin E and/or Se deficiencies \* Toxicities- ionophores, coffeeweed (Cassia occidentalis), white snakeroot \* Traumatic

Answer 149

\* usually in countries feeding hard feed to cattle \* antibiotics added to feed to change the microbial pop of the ruminant gut-- the way they act is they are ion transporters-- Sodium and potassiums backwards and forwards \* horses are really sensitive to ionophores \*\* small companies make horse feed after cattle feed, horse feed picks up traces of the ionophore from the cattle feed \*\* causes rhabdomyolysis and cardiomyopathy-- typically does not resolves-- many will die and the ones that survive have cardiac problems

Answer 150

\* Over exertion: common cause of ER in horses (and humans) - exercise that exceeds the underlying level of training - excessive intensity (speed) - excessive duration of moderate intensity exercise \* Excessive dietary soluble carbohydrates - animals on high grain diets are more likely to experience ER - effects on inuslin and glucose metabolism - psychogenic effects \* Temperment-- nervous animals are more likely to experience ER \* Concurrent illness - incidence of ER appears to increase with outbreaks of (viral) respiratory disease (EHV1, Equine Influenza virus A2) \* Electrolyte imbalances - insufficient sodium, potassium, magnesium, and calcium - inappropriate calcium: phosphorous ratios - poorly formulated rations - excessive sweat losses with prolonged exercise - incidence of ER has decreased when deficit corrected in some cases - usually difficult to diagnose with simple blood tests - measure urinary concentrations of electrolytes \* Hormone imbalances - incidence of ER is higher in females - episodes of rhabdomyolysis occurmost frequently during oestrus in some fillies/mares - some animals benefit from estrus suppression - a connection between disease and hormone concentrations has been difficult to prove \* Vitamin E and Selenium Deficiency - exercise associated with the production of free radicals - damage cell membranes and impair enzyme function--\> oxidative stress - vitamin E and selenium are components of the body's anti-oxidant mechanisms- free radical scavengers - little evidence of vitamin E or selenium deficiency in most cases of ER - benefits of supplementation are unproven - admin of vit E is very safe - excessive selenium admin causes severe toxicities --\> only supplement in areas of proven deficiency

Answer 151

\* Recurrent episodes of muscle stiffness, sweating and reluctance to move \* occurs most commonly in young THB, STB and arabian racing fillies as they begin race training \* Intrinsic muscle abnormality--\> defect in muscle contraction \* Speculated that calcium handling by muscle cell SR is abnormal

Answer 152

\* Glycogen accumulation is a result of increased production--\> rather than impaired glycogen breakdown \* Glycogen in affected animals is slightly different from that found in normal animals--\> less branched \* Mutation is GYS1 gene of QH--\> encodes glycogen synthase \* Functional analysis has revealed that GS activity is increased in horses with mutation - mutation causes gain of function of the GYS1 gene - enhanced activity and/or poor regulation of the mutant enzyme - cause of rhabdo in PSSM is unclear-- likely related to some defect in energy metabolism

Answer 153

\*\* CK of 5,000 is normal-- but 10,000s or 100,000s or more not normal!

Answer 154

They are not lame-- if they are it is very serious or something else is causing the lameness

Answer 155

Assessment of palmar soft tissue structures Assess each structure from proximal to distal Echogenicity and fibre alignment assessed - normal echogenicity - hypoechoic - anechoic \* cross sectional area - compare with contralateral limb - normal SDFT hourglass shape

Answer 156

Injuries of the suspensory ligament (interosseous muscle) are common in forelimbs and hindlimbs of horses. Lesions are typically classified as affecting the proximal, body, or branches of the suspensory ligament. \*\* proximal suspensory desmitis, Desmitis of the Body of the Suspensory Ligament, Desmitis of the Suspensory Ligament Branches

Answer 157

\* tendon repair - type I collagen replaced with type II - well aligned fibres replaced with poorly aligned fibres - increased tendon cross sectional area - recurrence generally occurs at junction of normal and repaired tendon

Answer 158

- swelling and pain on palpation - lameness mild or none

Answer 159

DDFT is always a bit brighter

Answer 160

\*\* also get a mottled appearance-- but increased cross sectional area Look at it longitudinally-- poor fibre alignment

Answer 161

\* Initial rest and anti-inflammatories \* controlled exercise program \*\* problem with superior check ligament desmotomy-- increases risk of suspensory ligament injury so it has gone out of favor

Answer 162

\* Body and branch lesions - predominantly TB and SB race horses - TBs forelimbs - SBs forelimb and hindlimb - pain and swelling - lameness variable

Answer 163

always check splint bone

Answer 164

\* 6- 12 months for most horses to come right

Answer 165

Prognosis of forelimb is good, hindlimb is poor \* shockwave therapy is hit or miss \* fasciotomy and neurectomy-- surrounded by splint bones

Answer 166

Rarely presented to vets most young horses get it and are spelled for 6 weeks occasionally recurrent occasionally stress fractures-- may progress to stress fractures (common in the states where they race on dirt a lot)

Answer 167

Proximal suspensory desmitis - no swelling - local analgesia \*\* improvements in multiple nerve blocks = either multiple problems or a problem that is spanning the whole region

Answer 168

\* Joint in extension throughout stance phase \* Modelling of subchondral bone in response to exercise-- sclerosis of third carpal bone; chip fracture; slab fracture \* Failure of subchondral bone to adapt to increased stress - subchondral bone necrosis - chip fracture - slab fracture

Answer 169

\* OR lateral swelling-- carpal sheath, antebrachiocarpal joint \* Flexion test- limited use; pain on flexion useful \* Lameness- often bilateral; mild lameness-- chip fracture OA; marked lameness-- significant pathology

Answer 170

flexed lateral view shown much better than a standing lateral-- separates radial carpal bone from intermediate carpal bone distal radial carpal bone proximal intermediate

Answer 171

Skyline of 3rd carpal bone

Answer 172

\* need to remove chip fractures-- therefore arthroscopy is common

Answer 173

\* Nerve blocks- pastern ring block- no response \* Low 4 point- no response \* midcarpal joint block-- changes to right front lame-- carpal problems are often bilateral problems \*\* subtle mottling of 3rd carpal bone-- if unsure CT but overkill \*\* Could arthroscope if money wasn't a problem-- but just time off

Answer 174

\* 3/5 is alarming-- severity \* Possible slab fracture or something else nasty \* 1-- radiograph because you don't want to block the horse if he has a decent fracture \*\* in a racehorse a skyline is mandatory \*\* will need to get our arthroscope in there and tidy up

Answer 175

\* Bicipital bursa and shoulder joint

Answer 176

\*\* could see-- hardly bring leg past the vertical

Answer 177

Bicipital bursa and shoulder joint-- good view of the femoral head and glenoid cavity

Answer 178

Dropped elbow appearance

Answer 179

\* Intra-articular

Answer 180

\* Limb deformities - angular limb deformities- lateral or medial deviation - flexural deformities- flexion of joint \* Septic arthritis/ osteomyelitis

Answer 181

Pastern flexural deformity

Answer 182

Pastern? flexural deformity

Answer 183

Congenital or acquired

Answer 184

OR acquired \* age, radiographs

Answer 185

Acquired - age - joint involved - radiographs - ID inciting cause

Answer 186

Angular deformity from growth plate - confinement, maintain foot balance, lateral/medial extension, surgery (growth acceleration-- periosteal strip OR growth retardation-- bridge growth plate) - foot extension- to side want limb to deviate to Osteochrondosis - angular deformity from growth plate - foot extension to side want limb to deviate

Answer 187

\* knee - 8-20 degrees- periosteal strip - \> 20 degrees- physeal bridge - prognosis guarded if angle greater than 25 degrees

Answer 188

\* Angular deformity from growth plate - fetlock 5-8 degrees- periosteal strip \>8 degrees- physeal bridge prognosis guarded if angle greater than 12 degrees

Answer 189

\* Tetracycline - 3 grams IV - large dose - warn owners potential for side effects

Answer 190

Crank on the leg and feel which tendon is tightest during surgery \* most commonly inferior check ligament desmotomy \*\* Check ligament desmotomy-- must combine with aggressive reshaping of foot

Answer 191

\* splinting \* Inferior check ligament desmotomy

Answer 192

DDX- owners may think mare stood on foal but rare-- tend to assume is septic joint

Answer 193

\* Radiography-- often starts with a subchondral infection-- subchondral often involved or physeal involvement-- important as you can't just flush the joint-- you would have to do something about the bone infection in order to win \* U/S- detect swelling in deeper joints, identify fibrin (shouldn't have a lot of fluid in the hip joint on U/S)-- fibrin means you have to flush the joint \* CT really useful because of bone involvement-- miss less than with radiography --- helps with surgical planning e.g. seeing obvious sequestrum therefore plan to currette it out

Answer 194

Prognosis- guarded if bone involved

Answer 195

\* Rule out fetlock sepsis-- synovial fluid \* Fibrin more concerned as you have to treat more aggressively-- more difficult to get it out of there \*\* after lameness got worse-- have to check for osteomyelitis lysis on axial boarder of the sesamoids-- likely communicating with digital sheath-- so we already knew we had sepsis in the fetlock joint, now it has spread to the digital sheath CT is when you could see it really well-- could see moth eaten lysis on axial side of sesamoids

Answer 196

\* problems of the axial skeleton \* Bilateral limb lameness \* Rhabdomyolysis

Answer 197

\* Muscle spasm - many treatments relieve muscle spasm - attracts quackery

Answer 198

\* Subtle clinical signs- objective measures of improvement unavailable \* Gets better on its own \* Responds to multiple treatments BUT DOESN'T ADDRESS UNDERLYING PROBLEM \*\* There is a placebo effect in animals where the owners perceive something is working but it hasn't especially if they've spent a lot of money

Answer 199

C- 7, T- 18, L-6

Answer 200

poor relationship between pathology and pain

Answer 201

\* Observe muscle mass, symmetry \*palpation- muscles, dorsal spinous processes, tuber sacrale (far from the sacroiliac joint, so pressure on it won't cause)-- if the horses flexes away especially the whole way, muscle spasm-- lots of potential causes \* Flexion and extension-- variable in horses-- good sign they have good mobility \* Examine limbs- could be due to lameness \*Gait- for lameness! Lunge at canter-- flexion and extension of spine... ridden

Answer 202

Only objective means of assessing back pain \* Local injection-- dorsal spinous processes, sacroiliac region \* Dorsal SI ligament- local infusion OR \* SI joint-- regional analgesia; Peri-articular

Answer 203

\* different exposures required-- facet joints (seen in RG here) \*\* Can't assess caudal lumbar spine or sacroiliac region

Answer 204

\* Spinal ligaments \* sacroiliac ligaments \*\* not easy to interpret

Answer 205

\* Increase muscle mass- unridden exercise \* Local injections-- anti inflammatories, counter irritants (iodine, stimulate acupuncture for longer-- no evidence) \* Manipulation \* Acupuncture \* Shockwave therapy

Answer 206

PM study of racetrack deaths-- 100% had SI degen. changes in SI joint

Answer 207

\* Dorsal sacroiliac ligaments and insertions \* Sacroiliac joints

Answer 208

\* Dorsal sacroiliac ligament injury OR \* Ilial stress fracture

Answer 209

\* Horse type-- older horses, larger horses, warm bloods \* Restricted hindlimb impusion, most obvious when ridden \* poor thoracolumbar muscle development \* Hind quarter asymmetry \* Straight hind limb flight (75%) \* Restricted thoracolumbar flexibility (35%) \* Pain on pressure over tuber sacrale (16%) \* reluctant to stand on one hindlimb for prolonged period (19%) \* Moved closely behind (18%) \* Tuber sacrale asymmetry-- very common, no association with sacroiliac pain, thought to be due to bending of ilium

Answer 210

\* Restricted hindlimb impulsion, most obvious when ridden

Answer 211

The only way to know for sure is blocking out-- block structures separately dorsal SI ligaments, SI articulation

Answer 212

\* RG: GA, overlying GIT-- so difficult \* U/S: dorsal SI ligaments \* Scintigraphy- able to image joint, attenuation of radiation by muscle, artefacts-- motion, positioning, bladder... views-- dorsal or oblique. 99% of horses with positive SI regional block had scintigraphic changes associated with SI joint

Answer 213

\* difficult to assesss treatments without accurate diagnosis \* Acute case-- rest, controlled exercise, anti-inflammatories \* Chronic-- periarticular injection of corticosteroids, phenylbutazone, unridden exercise, shockwave therapy

Answer 214

\* Common finding \* Significance can only be determined by nerve blocks \* Clinical findings-- poor performance, reduced muscle mass, reduced flexion and extension of spine, poor alignment of DSPs

Answer 215

\* HOrse ridden before and after local infusion to see if you can tell the difference

Answer 216

\* RG: over riding, sclerosis, focal lysis \* Scintigraphy: increased uptake, common finding-- may not be diagnostic or even source of pain

Answer 217

\* Rest, local corticosteroid injection, surgical resection, cutting interspinous ligament??

Answer 218

\* Nerve block starting at the bottom working way up and stop when blocking the lameness out-- start on which leg?? But horse isn't lame so how are you going to tell the nerve block worked? block one leg and look for it to go lame in the other leg \*\* bilaterally lame \*\* Radiograph the part that blocked (X-ray, fracture, bone cyst-- otherwise most things are equivocal) \* Alternatively-- X-ray the carpus because the horse isn't actually lame-- race horses often injure their carpus \*\* can't MRI or CT because you wouldn't know what to do \*\* Scintigraphy and nerve blocks could both help localize this lesion-- Scintigraphy of the forelimbs in this case \*\* under what circumstances are you going to stop doing and move onto something else MIN views-- two oblique, flexed lateromedial, skyline of the carpal-- see nothing? Might take more-- dorsopalmar, skyline of the middle row of carpal bones-- still see nothing? Another imaging modality or nerve blocks? General advice: Decisions you are going to make and why you are going to make them-- more interested in reasoning. Path you are going to take and why. Not always a right or wrong answer-- just has to be logical. \*\* MRI what part of the horse e.g. \* Radiographs-- what views you are going to take \*\* Clinical exam and flexion may be obvious you've already done so don't mention \* X-ray it, if I saw a fracture I have my diagnosis. If I see nothing then I need to go to ...

Answer 219

\* Vascular phase-- acquired immediately-- assesses blood flow \* Soft tissue phase-- 5-10 minutes after injection, increased uptake may be due to trauma, infection, rhabdomyolysis \* Bone phase- 2 hours post injection, increased uptake in areas of increased bone turnover

Answer 220

Rhabdomyolysis

Answer 221

Equine Condylar Fracture

Answer 222

Foal osteomyelitis

Answer 223

MRI Equine Foot

Answer 224

Low 4 point Not abaxial-- that just blocks the sesamoids-- will not block the fetlock

Answer 225

Pick which is worse and nerve block

Answer 226

Old horses in the paddock Not useful in racing horses effectively who are going to be swabbed

Lameness Flashcards

(423 cards)