Equine lameness Flashcards
(154 cards)
1
Q
What are the clinical signs of hoof lameness?
A
Increased or asymmetric digital pulses, increased heat in hoof capsule, pain on palpation of coronet, pain on hoof testers or hoof percussion
2
Q
What are the four main local anaesthesia distal limb blocks?
A
Palmar digital nerve block, distal interphalangeal joint block, abaxial sesamoid nerve block and navicular bursa block
3
Q
What does the palmer distal nerve block, block?
A
Caudal 1/3 of the hoof, N Bone, P3, variable amount of sole and the DIP
4
Q
What does the abaxial sesamoid nerve block, block?
A
Mid pastern and distal (entire foot)
5
Q
What must you avoid when you perform a distal interphalangeal joint block?
A
Minimizing trauma to the extensor process of P3
6
Q
What does a distal interphalangeal joint block, block?
A
DIP jt, sole and Nbone. Similar to PDNB but does not desensitize skin
7
Q
How should you prepare for hoof radiology?
A
Get rid of shoes, pack it, remove debri and dirt from the central, trim small amount of hoof and pack sulci, place the hoof on the position block so can get whole hoof
8
Q
What are the standard views of hoof radiology?
A
LM, DPr-PaD oblique, PaPr ? Pdi oblique and oblique views
9
Q
How thick is the sole usually?
A
6-9mm
10
Q
How thick is the dorsal wall normally?
A
11
Q
What is the distance from the extensor process to the coronet normally?
A
12
Q
What is a normal palmar P3 ? sole angle?
A
4-5 degrees
13
Q
What is the normal weight distribution between the toe and heel?
A
50/50
14
Q
How do you measure for ideal breakover?
A
6mm from cranial apex ? P3
15
Q
What are the two types of angle rotation of P3?
A
Capsular and phalangeal
16
Q
What causes seedy toe?
A
Inadequate hoof care, wet environment, separation of the wall from the white line leading to FB/material impaction
17
Q
What do you see radiologically with seedy toe?
A
Radiolucent area in the hoof wall
18
Q
How do you treat seedy toe?
A
Resection of diseased wall and laminae, bar shoe with clips
19
Q
What causes corns?
A
Ill-fitting shoe and a prolonged shoe interval
20
Q
How do you Tx corns?
A
Resection and wide web, deep seated out aluminium shoe - aluminium attenuates force better and is lighter. The deep seated out shoe takes the pressure off of the sole
21
Q
What causes Type 1 vertical hoof wall cracks?
A
Inadequate trimming, seedy toe, dermal/laminae cracks
22
Q
Tx for Type 1 vertical hoof wall cracks?
A
Resect to normal laminae, shoe with side clips
23
Q
What causes Type 2 vertical hoof wall cracks?
A
Coronary trauma, progress from solar surface
24
Q
Tx for Type 2 vertical hoof wall cracks?
A
Same as type one but may need complete hoof wall strip
25
What does thrush look like?
Thick, black, putrid discharge in frog sulci and heel bulbs usually
26
How do you Tx thrush?
Debridement, topical alcohol/iodine spray , dry environment
27
What are the differentials for 4-5/5 lameness score?
Subsolar abscess, penetrating sole injury/FB, septic synovitis, fracture, cellulitis
28
How do you Tx subsolar abscesses?
Drainage: look for white line 1st for black holes/tracts to follow. Sugar/iodine poultice. Tetanus prophylaxis and antibiotics/NSAIDs. . You need an adequate drainage hole
29
What are the clinical signs of septic osteitis of P3?
Persistent lameness and discharging tract, under-run sole, concurrent distal limb cellulitis, swelling around coronet.
30
How do you Tx septic pedal osteitis?
GA, tourniquet, abaxial sesamoid block. Curettage. Antibiotics, saline pack, hospital plate, 3 months rehab.
31
When would you consider using a hospital plate?
Septic pedal osteitis, keratoma resection, penetrating injuries to navicular bursa, laminitis with sole penetration
32
What is a canker?
Proliferative degeneration of the frog, solar corium and digital cushion. Caused by environment and specific bacteria and maybe BPV
33
How do you Tx canker?
Radical debridement under GA. Pack with metronidazole paste, change environment and improve hoof care
34
What causes sheared heels?
Uneven weight bearing, uneven heal growth, disrupted digital cushion and heels move independently
35
What can happen when uneven hoof loading?
Ossification of collateral cartilages ? often the lateral.
36
What are the presenting signs of P3 fracture?
Hx of racing or work, 4-5/lame acute onset, increased digital pulses, DIP effusion, variable hoof tester response
37
What is the most common type of P3 fracture?
2
38
What radiographs should you do to look at a P3 fracture?
Oblique radiographic views
39
How do you treat a P3 fracture?
Bar shoe + side/quarter clips, rim shoe, maintain shoe for at least 3-6 months. Repeat rads, maintain bar when returned to work.
40
What are the clinical signs of caudal heel pain? ? come back to do this part of lecture
Stiff gait, bilateral lameness, hoof tester pain over central 1/3rd of frog +/- heels, worse on mornings and hard ground but warm out of it
41
How many radiographs should you take with sole puncture wounds?
2
42
How should you treat solar puncture wounds?
Remove, clean up hoof and put in rap, radiograph with sterile probe in place for contrast, broad spectrum antibiotics
43
What synovial structures can be affected by penetrating FB into the sole?
N.Bursa, DIP joint and digital tendon sheath
44
How do you treat septic synovial structures?
Through and through needle lavage, athroscopy, athrotomy, street nail procedure
45
What is a keratoma?
Benign tumor originating from keritanized laminae
46
What do keratomas present like?
Chronic subsolar abscesses with hoof/sole wall defect
47
What is ?quitter??
Infection/necrosis of the collateral cartilage, secondary to trauma. Cartilaginous sequestrate, cartilage is avascular
48
How do you Tx quitter?
Surgical debridement, antimicrobials
49
What causes collateral ligament DIP desmitis?
Hoof imbalance
50
How do you Tx collateral ligament DIP desmitis?
Rest and corrective farriery
51
What may cause SDFT brand tendonitis?
Hoof LM imblanace
52
How do you Tx SDFT brand tendonitis?
Rest and corrective farriery
53
What is the hoof conformation of horses with navicular syndrome?
Small hoof, upright heels, tall heel, long toe, long heels
54
What is navicular syndrome?
A degenerative process that involves the NB and surrounding structures
55
What changes can you see on the NB radiologically with navicular syndrome?
Enlarged distal foraminae, loss of corticomedullary junction, remodeling of bone, cysts in medullary cavity, distal border fractures
56
How will you totally Tx treat caudal heel pain/navilcular syndrome?
IA medication in the DIP joint, raised heel alimunium shoe with rolled toe, intrathecal medication navicular bursa, PD neurectomy
57
How can you use corrective farriery for navicular syndrome?
Raised aluminum heel shoe, rolled toe aluminum shoe, egg bar aluminium shoe
58
What is laminitis?
Inflammatory disturbance to the laminae attachments between P3 and hoof wall resulting if structural failure of P3 hoof wall interface
59
What is the normal role of the basement membrane?
Attaches the basal cells of the lamellar epidermis on one side to connective tissue originating from the dorsal surface of P3 on the other side
60
What are some of the common clinical causes of laminitis?
Grain, colitis, enteritis, colic, endotoxaemia, nutritional, pleura-pneumonia, collateral limb overload etc.
61
What are some of the hypotheses for development of laminitis?
Nutritional, endocrinological, vascular, inflammatory, toxic, trauma, corticosteroids
62
Describe the inflammatory hypotheses
Interluekin 1 and 6 released from the BM cells and PMN, increased permeability, oedema, compartment syndrome
63
Outline the toxic mechanisms that may lead to laminitis
Endotoxin (-) LPS: potent stimulator of proinflammatory ? vasoconstriction, vessel lwakage, coagulation, hypotension, hypoperfusion. Exotoxin: Thermolysin and Strep. Exotoxin B ? collaginases. These two things can lead to basement membrane detachment and SEL characteristic histo-pathology of laminitis
64
How can corticosteroids cause laminitis?
Cause prolonged periods of hyperglycaemia, hyperinsulinaemia and hypertriglyceridaemia. Don?t exceed dose of 18-20mg
65
What are the stages of laminitis? What are some of the radiological signs of laminitis?
Developmental, acute, subacute ad chronic. P3 rotation (capsular of pharangeal), P3 sinking/distal displacement, decreased sole thickness, lucent lines/mummified laminae, modeling P3
66
Describe capsular rotation
The angle between lines drawn on the hoof wall and the dorsal aspect of P3.
67
Describe phalangeal rotation
The angle between the lines drawn along dorsal P3 or dorsal P1/P2
68
How do you tell if the P3 has sunk?
The distance between the coronet and the extensor process of P3
69
What are the two types of gas lines seen in laminitis?
Type 1: acute separation. Type 2: mummified laminae
70
What do you see with chronic laminitis?
?Ski-tipped? remodeling of dorsodistal P3
71
Outline the objective evaluation of laminitis
The angles are estimates ? determine if the rotation is mild, moderate or severe and if the laminitis is acute, subacute or chronic
72
What are the principles of Tx laminitis?
Treat the underlying cause, analgesia and hoof support
73
How do you treat laminitis with drugs?
Polymixin B (binds to LPS), NSAIDS etc.
74
Outline how you would provide digital support for a laminitic horse
Distribute weight evenly between sole and wall. Use a closed cell rubber for shoe or put in a sand yard (even weight distribution and unloads dorsal laminae).
75
Describe a deep digital flexor tenotomy
Mid MC3, standing sedation with a high 2 point block, 2 layer closure
76
What are some of the clinical findings of chronic laminitis?
Abnormal growth ringscloser towards the toe, excess heel and thick sole
77
How do you tell laminitis prognosis in the horse?
Degree of clinical improvement and rapid stabilization of P3 rotation
78
What are the key points to treating laminitis?
Ice hooves for developmental stage, Tx underlying cause, analgesia, hoof support, derotation once stable, wide webbed seated out raised heel aluminium shoe, deep digital flexor tenotomy for salvage and regular radiological assessment
79
What are the four radiographic views for fetlock radiographs?
LM, DP, 45d DLPM ob, 45d DMPL ob
80
Why is it important to do a flexed for fetlock LM?
So we can see the sagittal ridge the whole way around
81
What can DP of fore fetlocks show you?
To demonstrate the majority of subchondral bone defects
82
What are the clinical signs of fetlock disease?
Joint effusion, dorsal capsular thickening, + painful flexion, reduced range of motion on flexion, fetlock palmer pouch between SL and cannon bone
83
What will you find on lameness exam with fetlock disease?
+ fetlock pain on flexion tests, static fetlock flexion pain, blocking pattern: intra-articular and low 4 point
84
What are the common places for osteochondral fragments in fetlock disease?
Dorso-proximal P1 and proximo-palmar/plantar P1
85
How do you Tx osteochondral fragments?
Arthroscopic removal
86
What are the radiological signs of fetlock joint osteochondritis?
Supracondylar lysis, bone spur/osteophytes formation, modeling (P1/sesamoids), dorsal synovial pad enlargement, narrowing of joint space, palmar condylar flattening of MC3
87
Describe villonodular synositis
Proliferation of the dorsal synovial pad with lysis of the underlying bone. There is ossification of the pad and possibly OC fragments. Osteophytes may also be on the PSB (apex and base)
88
How do you measure supracondylar lysis?
On a LM radiograph measure up 10cm and measure the DP thickness of the cannon bone there with just above the condyles. If there is more than 4mm difference it is likely to be significant
89
Describe transverse ridge OA
Normally seen in TB/racing horses. MC3 or MT3 that causes bilateral lameness, variable response to flexions do flexed DO scintigraphy, I/A medication and a 2-3 month spell
90
Where are subchondral bone cysts normally on MC3?
Normally on the medial condyle of MC3
91
How do you Tx subchondral lucnecies on MC3?
Athroscopic debridement and evaluation with intralesion Tx
92
What are the 3 types of sagittal ridge osteochondrosis?
Type 1: lucency of the sagittal ridge with flattening, Type 2: non-displaced lucency, Type 3: displaced fragment
93
When do you commonly see condylar fractures?
Medial/lateral condyles of MC3,
94
What condyle does fractures normally propagate up from?
Medial
95
What do you need to remember when radiographing condylar fractures?
Always check palmar condyle for communication
96
How do you Tx lateral condylar fractures?
You can Tx conservatively or do a lag screw fixation
97
What radiographic view do you need to take if you want to look at the sesamoids?
Abaxial sesamoid skyline view
98
Describe the pathogenesis of sesamoiditis
The PSB under tension between SL and distal sesamoid ligaments. Exercise induced one remodeling response and widening of the vascular channels. If there is more than 2 vascular channels or one is wider than 2mm it is sesamoiditis. Tx is rest for 3-6 months and you have to make sure you evaluate the suspensory ligament to make sure it?s okay
99
What are the two best prognosis sesamoid fractures?
Apical and abaxial
100
How do you treat a sagittal P1 fracture?
Lag screw and distal limb cast
101
How do you Tx short incomplete sagittal fractures?
Conservative management/confinement/repeat radiograph
102
What is the most common site for enthesiophyte formation?
The palmar site of P1
103
What is the Tx for low ring bone?
If non-articular conservative Tx: rest and reasses
104
What are the most common changes seen with high ringbone?
Osteophytes and capsular enthesiophytes, cartilage thinning, subchondral bone lysis and collapse
105
How do you Tx high ringbone?
This is severe irreversible OA of the PIP joint thus perform surgical arthrodesis
106
How do you Tx proximal P2 avulsion fractures?
Acute especially = removal
107
How do you Tx P2 comminuted fractures?
Can Tx conservatively or perform internal fixation (Plate/lag screw/cast) BUT use careful case selection
108
Describe tendon sheath effusion
Around the SDF and the DDF, be worried about the tendon sheath in these patients. The plantar/palmar annular ligament is considered thickened if >2mm
109
What are the clinical signs of carpal disease?
Effusion, variable flexion test results, blocked soundness to intraarticular, bilateral disease, stiff gait, reduced carpal flexion during anterior phase of stride
110
What are some of the common sites of carpal injury?
Dorso-medial aspect of joint,
111
What are the sites of OC fragmentation on the carpus?
Distal RC, proximal C3, distal IC, distal lateral radius
112
What should you be thinking of you do a carpal joint nerve block and the horse take more than 30mins to go sound?
Be suspicious of proximal suspensory ligament desmitis
113
What are the standard radiographic views of the carpus?
LM flexed, DLPM ob and distal row skyline
114
What is the Tx for synovitis?
6-8 week spell, I/A medication, systemic PPs
115
Why do we do skyline of the distal row radiography?
To look for C3 disease ie lucency of sclerosis of radial facet
116
What are the signs of physitis?
Lysis, sclerosis and widening of physis
117
What carpal bone is prone to cysts?
Distal radius ? also ulna, radial carpal bones
118
What is the most common fracture of the carpus?
Distal radio-carpal osteochondral fracture
119
Describe C3 frontal slab fractures
On the radial-intermediate facet, incomplete ones ? remove (only has one articular surface involved), complete (involves both articular surfaces) ? lag screw fixation
120
Describe C3 sagittal slab flactures
Radial/intermediate slab, do a distal row skyline view. Lag screw fixation of arthsoscopic debridement or conservative Tx
121
What is the cause of accessory carpal bone fractures?
Avulsion of palmar attachements as loaded, crushed between carpal bones, trauma (kick)
122
How do you Tx accessory C bone F#?
Conservative 3-6 months confinement OR Sx fixation
123
Describe intercarpal ligaments injury
Medial intercarpal ligament that can tear to various degrees/grades
124
What are caudal radius osteochondromas important?
They impinge into the carpal sheath and DDFT ? carpal sheath effusion and haemorrhage ? surgical removal via direct or tenoscopy
125
What are splints?
Enlargements of the splint bones that may cause lameness
126
How do you treat a medial splint of MC2?
You can only remove the distal 2/3 without internal fixation of remaining proximal MC2
127
How do you Tx hind lateral bone splint?
You can remove the whole thing but be careful of joint infection
128
What causes shin soreness/bucked shins?
There is high strain cyclic fatigue and boney modeling. If the cyclic fatigue outdoes the modeling response ? lameness. Horses typically go shin sore after first gallop or trial.
129
How do you Tx shin soreness?
Spell for three months. Use modified program ? shorter faster runs twice a week. Reduce canter work and increase gallop work
130
Describe the pathogenesis of sin soreness
Microfracture in the middle/distal third of MC3. You can?t see the microfractures on radiograph but you may see the periosteal response ? callous formation on the dorsomedial cortex
131
Which MC/MT is very prone to sequestrum?
Dorsolateral cortex of MC3
132
How would you Tx lateral condylar F# of MC3?
Lag screw repair +/- distal limb cast
133
How should you radiograph for condylar F#?
Make sure you get the full cannon bone and take multiple views
134
How can you Tx condylar F# in general?
Internal fixation: single or double bone plate and selective lag screws
135
What are some common abnormalities of the tarsus?
OC, OA, fractures, developmental, cysts
136
What joints in the hock communicate?
The tibiotarsal and the proximal intertarsal always do. The proximal intertarsal and distal intertarsal joints rarely communicate
137
What are the common radiographic views of the tarsus?
LM, DP, obliques and flexed views
138
Which joint is the only joint of the tarsus where we can appreciate joint effusion?
Tarsocrural
139
What are the four main sites of osteochondrosis of the tarsus?
Distal intermediate ridge of the tibia (DIRT), lateral trochlear ridge of talus, medial trochlear ridge of talus and medial malleolus of tibia
140
What is the most common OCD location in the tarsus?
Distal intermediate ridge of the tibia (DIRT)
141
How do you treat DIRT lesions?
Remove early and decrease chance of persistent synovial effusion
142
What is the second most common OCD location in the tarsus?
Lateral trochlear ridge of the talus
143
How do you treat OCD in the lateral trochlear ridge of the talus?
Athroscopic removal ? fair prognosis
144
Describe tibial physitis
Enlargement of the distal end of the tibia due to, the metaphysic being broadend, asymmetrical and has irregular sclerosis
145
What is the most common cause of lameness in the hind limb of performance horses?
Osteoarthritis
146
What is some of the common history of horses with OA of the hock?
Straight hind limb breed, mostly adults, lumbar/back muscle pain, stiff coming out of stall, improves then lamer with work, sour during work, becomes better then gets worse again
147
How do you diagnose OA of the hock?
Signalment, history, clinical signs, boney swelling on the medial distal joints, flexion tests, radiography
148
Describe the radiographic changes of OA in the hock
Osteophytes, subchondral bone lysis, narrowing or loss of joint space
149
How do you try Tx OA of the hock?
Cortisone/HA injections +/- pentosan. Disease will always progress to a point where disruption of subchondral bone plate and fusion of joints is required ? surgical or chemical arthrodesis
150
Describe the post injection Tx for OA in the tarsus
Discharged 7-10 days on PBZ, exercise commence after 7-10 days, return to soundness by 12 months hopefully
151
What tarsal bones normally get slab fractures?
Central and 3rd tarsal bones
152
Describe malleous fractures
They are usually traumatic and involve collateral ligament. Small = athrotomy and large = lag screw
153
What can cause calconeal osteomyelitis?
Secondary to trauma, usually wound associated. May not become radiologically detectable for several weeks. Often 4/5 lame and need a surgical curette with a raised heel shoe
154
In what animals do we normally see collapsed tarsal bones?
Foals that have incomplete ossification
