Chapter 91 - Foot Flashcards
1
Q
Trush refers to
A
an infection that leads to tissue necrosis in the frog area
2
Q
which areas are most often affected by trush?
A
frog central and lateral sulci
3
Q
what are the characteristics of trush?
A
soft and slimy and emit a characteristic foul-smelling odor
4
Q
What are the predisposing factors of trush?
A
lack of conditions with manure and urine (poor stall hygiene)
contracted hoof and lack of exercise
poor horn quality
5
Q
What is the treatment of trush?
A
hoof care and good stall hygiene
All damaged horn is removed + desinfecting solution
protective bandage with povidone-iodine sponges
6
Q
what is the prognosis of trush?
A
depends on stall hygiene
7
Q
White line disease is
A
a deterioration of the white line of the hoof capsule resulting in the loss of the bond between the hoof wall and the sole
8
Q
cause of white line disease
A
poor quality of the horn which allows colonization of different bacteria and fungi
typical of warm and humid clime
9
Q
Where does the lameness come from in the case of white line disease?
A
When the hoof wall begins to separate from the sole, the hoof wall is exposed to increased tensional forces, which leads to the development of inflammatory processes in the sensitive laminae and results in lameness - hoof wall may become undermined and eventually form a hollow wall
10
Q
What is the treatment of white line disease?
A
debridement of affected tissues and hoof wall resection during the debridement
place nails higher than normal to prolong the duration
11
Q
Hoof wall separation what is the cause?
A
common in working horses in chronic cases results from accumulation of soil, bacteria and fungi that separate the laminae in the hoof wall - can be an extension of white line disease
12
Q
What is the therapy of the hollow wall separation
A
Successful therapy can be achieved only when all diseased and necrotic horn is removed
Replace the empty space with polimerized products that will be hornlike products and ca be reinforced by fiberglass webbing
13
Q
A
Figure 91-2. Photo showing the sole of a hoof in a mule with severe white line disease. Necrotic and desiccated horn has been removed from the white line area.
14
Q
A
Figure 91-3. Illustration showing hollow wall on the left side (dark area) of a hoof.
15
Q
Hoof wall crack what is it?
A
occurs as a longitudinal disruption of the hoof wall parallel to the horn tubules and lamellae.
16
Q
Hoof wall cracks can affect which areas of the hoof?
A
involve the entire length of the hoof wall,
only the proximal hoof wall near the coronary band,
or only the distal hoof wall
17
Q
you can classify cracks into 2 types name them
A
superficial - only superficial hoof wall
deep - contacts sensitive laminae causing inflammation and lameness
18
Q
Horizontally oriented hoof defects parallel to the coronary band are called
A
hoof crevices and are managed as cracks
19
Q
Causes of hoof crack
A
diverse
Poor horn quality or a horn wall that is too thin are predisposing factors.
Abnormal hoof angles can produce significant tension gradients within the hoof wall, which develop into cracks.
20
Q
what is the classification of the hoof wall cracks regarding the length?
A
proximal
distal
entire lenght
21
Q
Describe the cause of proximal hoof cracks
A
local trauma (Figure 91-8),
inflammation,
or scar tissue formation near the coronary band. Because of this damage, poor quality horn is produced, promoting the development of a hoof wall crack. These cracks slowly extend distad as the horn grows.
22
Q
A
Figure 91-5. (A) A hollow wall section limited to the proximal part of the hoof wall is removed with a Dremel tool. (B) The exposed desiccated laminae are shown.
23
Q
A
Figure 91-6. Different locations of hoof wall cracks. a, Dorsal crack extending over the entire length of the dorsal hoof wall; b, proximal lateral hoof wall crack; c, distal lateral hoof wall crack.
24
Q
A
Figure 91-8. Proximal medial hoof wall crack self-inflicted by the shoe of the contralateral foot.
25
describe the cause of distal hoof crack
Poor horn quality associated with excessive workload and poor hoof hygiene can lead to development of hoof cracks at the distal hoof wall (see Figure 91-6).
26
treatment of distal hoof crack
A horizontal groove may be cut at the most proximal aspect of the crack, and the foot should be trimmed very short to prevent proximal and deep extension of the crack. If these management practices do not stop the progression of the crack, more aggressive surgical techniques are required (see later).
27
Figure 91-7. Illustration of a hoof wall with a window inserted to show the depth to which cracks can penetrate. a, A deep or perforating hoof wall crack involving the sensitive laminae; b, superficial hoof wall crack
28
Figure 91-9. (A) Hoof with a crack attributable to a long and steep medial wall and uneven heels.
(B) Illustration of a contracted hoof with a distorted coronary band and a hoof crack.
29
Hoof cracks are more medial or lateral?
More lateral
30
What is the cause of entire lenght hoof crack?
Usually is trauma in the coronary band
31
Often this type of hoof crack is found in hooves with particularly ________ ______________(2w)
long sidewalls (Figure 91-9).
32
Predisposing factors of entire length hoof cracks
1. Uneven heels and displacement of the heel bulbs are predisposing factors.
2. Hoof wall cracks can also be caused by faulty shoeing practices, such as shoes that are too short, branches that are too narrow, side clips applied too far back, uneven hoof soles, and hoof nails inserted too far caudally.
33
Diagnosis of hoof crack
The diagnosis is usually made on close visual inspection of the hoof.
34
Difference of treatment between superficial and deep cracks
Deeper layers of the crack often are filled with dirt and manure. Lameness is a prominent feature of deep or perforating hoof wall cracks. Conversely, superficial horn cracks are not associated with lameness and many do not require treatment.
35
Figure 91-10. Illustrations: (A) and (B) The hoof horn surrounding the cracks is carefully removed and smooth transitions from the laminae to the horn are established before each crack is covered with artificial horn (C).
36
Treatment of hoof cracks
symmetry of the hoof - trimm the heels on affected side short --> reduce pressure
The old shoe is removed, and the hoof is properly trimmed.
shod with a bar shoe, and the sole is filled with silicone and covered with a metal plate. This reduces pressure in the heel region, which is especially beneficial when the crack is located in this area
Trimm the hoof wall short in the exact place of crack in coronary band to avoid movement
Fixation device is placed after debridement (Figure 91-11)
If you place exotermic components you should wait for a thin layer of horn before applying directly in the sensitive laminae
37
Figure 91-11. Illustration showing various devices applied to the hoof to repair cracks. a, Umbilical tape laced around small protruding screws in the hoof wall; b and c, clamps of various designs inserted into the hoof wall; d, a metal plate glued over the crack; e, a metal plate spanning the crack and fixed to the hoof wall with small screws.
38
what is the principle in the treatment of cracks?
The hoof wall must be covered with artificial horn material over almost its entire length to prevent recurrence of a crack (Figure 91-12). patient should have stall rest few month
39
Figure 91-12. Lateral hoof crack in which the involved hoof wall has been removed and the defect filled with artificial horn.
40
Prognosis of hoof cracks
Good to guarded
41
What is a keratoma?
keratoma is a thickening of the hoof horn that extends toward the inside of the hoof (Figure 91-14).
42
Figure 91-14. Illustration of a keratoma of the hoof capsule. (A) First manifestation close to the white line (arrow). (B) View from within the hoof capsule; note the extra horn tissue that has formed near the toe.
43
What is the cause of keratoma?
The most common cause is localized inflammation or trauma at the transition between new horn produced at the coronary band and the hoof wall. This results in the formation of scar tissue in that location, which gradually grows distad as new horn is produced.
44
What is the treatment of keratoma?
Partial thickness wall removal
45
how many types of keratoma exist?
3 types
1 - cylindrical - columnar shap - protrusion parallel to the horn tubules
2 - spherical - anywhere in the hoof
3 - epidermical cysts
46
where is common locations of keratoma?
dorsal, dorsolateral, or dorsomedial aspect of the wall.
47
The keratoma consists of poor quality horn (Figure 91-15), which decays early, allowing bacteria and fungi access to the inside of the hoof wall. - True or false?
True
48
how do you diagnose keratoma?
recognize the abnormal configuration of the white line. Typically, the lamellar horn of the white line is replaced by tubular horn and scar tissue (Figure 91-16, A).
recognize the abnormal configuration of the white line. Typically, the lamellar horn of the white line is replaced by tubular horn and scar tissue (Figure 91-16, A).
Radiograph (Fig 91-16 B)
CT and MRI to do minimal invasive intervention
49
diferential diagnosis of keratoma
calcified hematoma, fibroma, squamous cell carcinoma, and malignant melanoma
50
what is the radiographic description of keratoma?
In advanced cases, a circular lytic area in the distal phalanx can be recognized radiographically (see Figure 91-16, B). This area should not be mistaken for the naturally occurring toe crena at the dorsal aspect of the distal margin of the distal phalanx. Often, a sclerotic border delineates the lytic area (see Figure 91-16, B)
51
Figure 91-15. Photographic views of a transverse section of a hoof with a keratoma. (A) Solar view of the keratoma, (B) Transverse cut through the bone and the hoof capsule. a, Keratoma and surrounding bone; b, normal pedal bone.
52
Figure 91-16. (A) Photograph of the sole of a foot with a keratoma showing focal chronic infection near the toe. (B) Dorsoproximal-palmarodistal oblique radiographic view of the same hoof showing a lytic area in the distal phalanx extending proximally along the hoof wall (surrounded by arrows), which is characteristic of a keratoma.
53
Figure 91-17. Three-dimensional reconstruction of a computed tomography image of a distal phalanx affected by a keratoma. Note the large bone defect caused by the keratoma.
54
Figure 91-18. Partial hoof wall resection for keratoma removal. The portion of hoof wall left near the ground surface provides stability.
55
What are two surgical techniques for keratoma removal?
Complete hoof wall removal
Partial wall removal
56
What is the main goal of the surgery?
Remove: abnormal horn as well as the abnormal sensitive laminae
The hoof wall defect may be filled with artificial horn as soon as the sensitive laminae have healed.
A special shoe with large clips placed on either side of the defect should be applied to the foot
57
describe the surgical procedure
Tourniquet - the horn just above the origin of the keratoma is first removed in the standing horse with the help of a Dremel tool. The second stage of the procedure is best carried out under aseptic conditions with the horse under GA where the altered laminae and the keratoma are removed at their origins (Figure 91-18). This procedure may also be carried out in the standing horse if a ring block is carried out at the level of the metacarpophalangeal (MCP) joint.
Antiseptic pressure bandage is applied to the phalangeal region, and the tourniquet is removed.
58
In how many days of interval you should change the bandage of keratoma?
Every 3 - 4 days intervals
59
How much time should the horse be confed to a box stall in keratoma case?
The horse should be confined to a box stall for 4 to 6 weeks, during which time routine bandage changes are done
Hand walking for approximately 2 to 3 months, followed by light exercise under saddle
60
In keratoma case after 4 - 6 weeks when the horse develops horn what can you apply in the hoof wall?
If healing progresses normally, the defect may be filled with artificial horn - wall defect with an amikacin-impregnated polymethyl methacrylate (PMMA) plug
Hand walking for approximately 2 to 3 months, followed by light exercise under saddle
61
What is the prognosis for keratoma treatment?
Surgical treatment is associated with a significantly better prognosis than conservative treatment and a success rate of 83% compared with 43% for conservative management was reporte
62
Hoof abcess has predispostions?
No breed or age predispositions are known.
63
Hoof abcess causes
1 . Placement of a horseshoe nail too close to the sensitive laminae causing bacterial infection in close proximity to the sensitive laminae.
2. Insertion of a horseshoe nail directly into the sensitive laminae resulting in infection.
3. Small pointed rocks penetrating the sole horn.
4. A penetrating foreign object, for instance a street nail.28
5. A sole bruise, creating an optimum environment for bacteria that normally enter the horn tubules.
64
cardinal signs of hoof abcess
"fracture" type pain
warmth on the hoof
digitaal pulse
fever sometimes
swelling of the limb often misdiagnosed with septic tenosynovitis
65
diagnosis of hoof abcess
positive hoof tester
radiografy
regional nerve block
66
Treatment of hoof abcess
removal of the shoe
placement of povidine- iodine or creosote bandage to clean and debride the abcess in the next day
Debridement of the necrotic tissue
Lavage with iodine solution or H2O2 (max. 3%) and covered with a povidone-iodine–soaked gauze sponge and a hoof bandage
The bandage is changed every 2-3 days and when finally dry the horse should be shod
AINS
67
Figure 91-22. Septic arthritis of the DIP joint is a potential complication of a hoof abscess. The opening into the DIP joint is clearly visible (gray arrow). The diseased bone was curetted (black arrow). It was necessary to lance the abscess proximal to the coronary band to allow flushing (white arrow).
68
Figure 91-20. Some hoof abscesses drain from the coronary ban
69
What is the medication you should give in case of abcess?
Administration of nonsteroidal antiinflammatory drugs (NSAIDs; e.g., phenylbutazone) is advised. Antimicrobial therapy is only indicated when involvement of deeper structures is suspected.
70
what is the prognosis of hoof abcess?
Generally, a good prognosis can be given, even though advanced abscesses can take weeks to heal completely
71
If an abcess is not well managed where can it break through?
it can break through at the coronary band (Figure 91-20) or extend deeper into the foot.
72
In case of coronary band affection what should you do?
Lavage daily from coronary to distal wwith iodine povidone 3%
73
How can chronic abcess be missed?
especially if the horse has been treated with analgesics, which can mask clinical signs and prevent timely recognition + avoid maturing of the abcess
74
How do you diagnose a chronic hoof abcess?
During physical examination of the foot you can follow the tract with a probe
radiographic exam
75
What are the radiographic changes visible in chronic hoof abcess?
Lytic changes in the distal phalanx, also known as the pedal bone, can develop as a result of a chronic abscess as well as after aseptic local inflammation.
76
In chronic cases where can the hoof abcess can go?
the dorsal and lateral hoof wall in a proximal direction, eventually breaking out at the coronary band (see Figure 91-20) or invading the coffin joint (see Figure 91-22); the sole, potentially undermining it completely; and the distal phalanx, resulting in septic pedal osteitis
77
What is aseptic pododermatitis?
poor shoeing technique, excessive use of the horse under difficult conditions, such as hard, uneven ground, and frequent kicking against a stall wall
78
Figure 91-24. Marked reddening (surrounded by arrows) of the sole near the frog in a horse with aseptic pododermatitis (severe bruising).
79
How do you diagnose aseptic pododermatitis?
The signs are typical but not very specific, which occasionally leads to misdiagnosis of the problem (Figure 91-24). The hoof is slightly warmer than normal, pulsation of the palmar arteries is usually increased, and a positive pain reaction can be elicited with the hoof testers. In most cases, palmar digital nerve anesthesia relieves the lameness. Radiography helps to differentiate the problem from laminitis or a fracture in this region. Keratoma is part of the differential diagnosis in cases of chronic persistent pododermatitis.
80
How do you treat aseptic pododermattis?
1. shoe must be removed
2. Application of creosote bandages for 3 or more days followed by dry bandages for several weeks is very effective.
3. NSAIDs may be required if there is persistent pain.
4. Hand walking on soft ground for short periods is optional, and after 7 to 10 days the horse is reshod.
81
Nail prick refers to an injury caused by
an injury caused by inadvertent insertion of a nail through the sole and sensitive laminae during shoeing.
82
Street nail refers to puncture
to puncture of the solar surface of the hoof by nails or other sharp objects, such as screws
83
A hoof is nail bound when a
a horseshoe nail is driven too deep into the horn, causing excessive pressure on the corium.
84
All 3 conditons of street nail, hoof nail and nail prick result in 3 things, name them:
result in pain, inflammation, and infection.
85
which structures can be affected by the nail?
are often deep and can have disastrous effects when structures such as the distal phalanx, distal sesamoid bone, DIP joint, navicular bursa, deep digital flexor tendon (DDFT), or tendon sheath are penetrated (Figure 91-25).
86
Figure 91-25. Depending on the site of entry of a sharp foreign body into the foot, different anatomic structures may be affected. a, The distal phalanx at the toe; b, the insertion of the DDFT at the dorsal third of the frog; c, the DDFT, impar ligament, and possibly DIP joint at the middle of the frog; d, the DDFT, distal sesamoid bone, and navicular bursa at the palmar/plantar third of the frog; e, the hoof cushion, DDFT, and tendon sheath at the palmar/plantar aspect of the frog; f, the hoof cushion at the palmar/plantar-most part of the frog.
87
The penetrating object is often contaminated with soil, rust, or manure, which can lead to _____________ ____________ (2w)
serious infection
88
The superficial wound in the sole usually seals quickly, leaving no area for drainage, and the anaerobic environment created favors the growth of (name the organism)
Clostridium tetani, the cause of tetanus.
89
How do you diagnose street nail?
moderate to severe supporting-leg lameness - stand tip of toe
Fever
Hoof is warmer than normal
increased pulsation of the digital arteries
Severe pain. In horses with severe acute lameness, the hoof must be thoroughly cleaned and examined for a foreign body or puncture wound (see Figure 91-25).
Radiograph
90
How do you treat street nail
Note point of entry marked on the sole or recorded on paper, because it will rapidly become unapparent.
The point of entry is cleaned, and the entire hoof is bandaged.
If radiographic equipment is available, radiographic images are taken before the removal of the nail.
Based on the location, direction, and depth of the injury, the horse may be treated on site or referred to a clinic.
When there is suspicion of injury to deeper structures, such as the navicular bursa, DIP joint, or the digital flexor tendon sheath, the horse must be referred immediately for surgical treatment.
Broad-spectrum AB
Tetanus antitoxin
Clinical examination, the foot is desensitized by means of an abaxial sesamoid nerve block.
Remove shoe + entire hoof is trimmed.
The decision to pursue further treatment is based on the results of the clinical examination and radiography. The puncture tract is carefully cleaned and disinfected.
A sterile metal probe is inserted into the puncture tract, and the hoof is radiographed in two planes (Figure 91-26, A and B).
Contrast studies help in determining whether there is involvement of the DDFT and the adjacent synovial structures. Injection of contrast material into the navicular bursa, the DIP joint, and the digital flexor tendon sheath (DFTS) independently,
91
92
Describe the surgical tx of street nail
This procedure entails two parts:
1. initial débridement of the sole (horse is standing and sedated)
2. followed by aseptic treatment of the puncture wound and the involved deeper structures (under general anesthesia) (Figure 91-27).
With the horse sedated and standing, the hoof is cleaned and the horn around the puncture tract is carefully removed down to a thin layer of horn that can be cut with a scalpel blade.
The hair from the hoof to the fetlock joint is clipped.
The prepared area is cleaned with chlorhexidine scrub (Hibiscrub) and covered with a bandage.
The horse is subsequently positioned in LR GA + a tourniquet is applied. Occasionally, it is necessary to remove additional horn at this time. All affected tissues around the puncture tract are excised. The horn around the tract is removed in an area measuring approximately 3 × 3 cm. The corium and subcutis are then removed and the underlying structures are exposed. If the foreign body has penetrated the DDFT, a 1.5 × 1.5 cm area of the tendon
Curettage of FB has penetrated the P3 or the distal sesamoid bone (Figure 91-28). With perforation of the impar ligament and penetration of the DIP joint, the ligament must be resected and the joint as well as the navicular bursa must be lavaged. Involvement of the digital tendon sheath requires thorough lavage.
The affected synovial structures are lavaged with copious amounts (several liters) of lactated Ringer’s solution to which AB have been added. Endoscopic evaluation and flushing of the synovial structures is recommended. A pressure bandage is applied, followed by a hoof bandage and a wedge under the heel. Repeated regional intravenous perfusion with antimicrobials is recommended.
93
What is the size of horn around the tract you have to remove?
3 x 3 cm
94
If the foreigh body has penetrated the DDFT how much of tendon you have to remove?
1.5 x 1.5 vm are of tendon
95
Figure 91-27. Illustration of a street nail operation. (A) Localization of the entry point. (B) Subcutis and sensitive laminae are removed. (C) The DDFT is fenestrated. (D) Illustration of the puncture wound in a parasagittal plane.
96
Figure 91-28. (A) Photo showing the appearance of the surgical wound 10 days after removal of a foreign body (street nail operation) that penetrated the distal sesamoid bone. (B) Intraoperative view showing the site of penetration of a nail into the impar ligament
97
Figure 91-29. Navicular bursoscopy in the horse in lateral recumbency using the direct approach. (A) Illustration of the surgical portals. (B) Close-up view showing the anatomic structures involved. (C) Intraoperative view of the navicular bursa. AP, Arthroscopic probe; NB, navicular bone.
98
Figure 91-30. Medication-plate shoe used for postoperative protection of a foot after surgery. The wound can be dressed daily by removing the plate.
99
What is the % prognosis of puncture wound of the sole of synovial structures?
only 29% become sound after synovial treatment - prognosis guarded
100
What was the % of horses that with navicular bursotomy for treatment of contaminated/septic bursitis returned to their previous level of use?
75 - 84 % Navicular bursotomy for treatment of contaminated/septic bursitis, mostly arising from street nail puncture wounds, was performed in 19 horses, showed a better outcome. All horses in this study survived to discharge and 84% returned to their previous level of use.
Additionally, another case series of 16 horses with contaminated and septic bursae that were treated with bursoscopy reported a success rate of 75%.
101
Horses with septic bursae are reported to have better prognosis in the fore foot or hind foot injury?
Equids with a hind foot injury have a more favourable outcome than those with a forefoot injury. One suggested reason for this may be the fact that more weight is carried on the FL
102
Which condition may require neurectomy in case puncture of the sole?
Injury to the distal sesamoid bone can eventually result in adhesions between the bone and the DDFT, necessitating neurectomy.
103
Scalping injuries are
Coronary band and heel injuries occur at the transition between the skin and hoof capsule
104
Scalping injuries are caused by
They are usually caused by over-reaching, where one foot treads on the coronary band or heel of another foot. Heel calks on shoes can result in very deep injuries as well.
105
Figure 91-31. (A and B) Deep coronary band injury. (C and D) Primary wound closure was used for the skin.
106
Treatment of scalping injuries
damaged horn should be removed to allow drainage of wound secretions.
Heavy-duty scissors, rongeurs, or a hoof knife are ideal for this.
The wound is subsequently cleaned with a mild disinfectant solution.
The injury to the skin is best treated by primary closure, when possible, and the application of a foot cast is recommended (Figure 91-31).
107
Trauma to the corium result in a serious condition
This type of injury is particularly problematic when the coronary corium is involved; damage to the horn-producing cells results in the production of poor-quality horn.
108
How do you treat in case of laveration to the corium?
A pressure bandage is applied to injuries that are bleeding severely. The bandage is changed daily until a stable and healthy layer of horn is formed.
109
Define canker
represents abnormal horn proliferation that occurs most frequently in the frog region. It is rarely seen in other areas of the hoof (Figure 91-32). It is not a true neoplasm, but rather a chronic inflammatory reaction characterized by massive parakeratosis.45 The sensitive laminae hypertrophy and the superficial horn and corium degenerate.
110
What is the cause of canker?
The cause of canker is not known, although unsanitary stall conditions appear to be a predisposing factor.
Long-standing thrush is thought to result in canker formation because it initiates degeneration of the horn cells. Horses that are kept in moist and warm stalls with urine-soaked bedding often suffer from canker.
111
There is a breed predisposition?
Yes, it can affect all horses but draft horses are predisposed
112
Canker affects more commnly the forelimbs or the hindlimbs?
Hindlimbs
113
Was Treponema sp associated to canker?
In a recent study, Treponema sp. DNA was detected in the majority of hoof canker and control samples. However, sequences that were highly similar or identical to bovine digital dermatitis sequences tended to be detected only in canker lesions
114
which type of bovine papilloma virus have been associated to hoof canker?
Using a PCR-based technique, the same research group reported substantial evidence for an association between sarcoid-inducing bovine papilloma virus types 1 and 2 (BPV-1, BPV-2) and equine hoof canker
115
canker is associated with which type of bacteria?
gram-negative anaerobic bacteria
116
what is the typical aspect of hoof canker in terms of consistency?
Horn of rubber-like consistency that breaks easily on the surface is characteristic of canker. The horn produced by the epidermal cells affected by canker is soft, greasy, and friable. Cauliflower-like growths that are not cornified at the surface but covered with a greasy, greyish-white material are typica
117
Clinical signs of hoof canker
The area is painful to pressure and horses are usually lame. When traumatized, the area bleeds profusely. The poor horn quality can result in injury and infection of the underlying structures.
118
Diagnosis of hoof canker how do you proof?
Histology of the resected material confirms the diagnosis.
119
Figure 91-33. Illustration of a sagittal view of a hoof with canker. The dotted line represents the level of the surgical cut needed for removal of the frog.
120
Figure 91-35. Photograph taken 4 months after removal of the entire frog showing good healing.
121
Figure 91-34. Postoperativ
122
what is the surgical approach of hoof canker
Tourniquet midmetatarsal/metacarpal- local anesth - aseptic preparation - surgical débridement all necrotic and abnormal horn is removed standing or GA
All abnormal horn is removed so that the area can be thoroughly cleaned and cut with a scalpel blade (Figure 91-33).
The transition between abnormal and healthy horn is determined during paring with a hoof knife. A cut is made around the frog to define the surgical field. Then, beginning from the palmar or plantar surface, the entire frog is removed
AVOID apex of the frog
123
what should you avoid during hoof canker resection
apex of the frog
124
After surgical debriment of hoof canker what is the next step?
Placement of bandages taht requires a lot of time and patience
125
what is the mixture used in hoof canker, be specific with grams
The defect is covered daily with a mixture of 20 g iodoform iodine, 20 g zinc oxide, 20 g tannic acid, and 40 g metronidazole;
126
what is the local treatment? do you give systemic AB in case of canker?
The wound is subsequently bandaged or covered with gauze
Administration of local or systemic antibiotics may be necessary; chloramphenicol and metronidazole are particularly effective for topical treatment; alternatively, local and systemic treatment with doxycycline and oxytetracycline has been recommended.
127
when is doxycycline advised?
Systemic antibiotics should be administered when more than one hoof is affected.
128
beside antibiotics what other treatment is advised?
Long-term administration of systemic prednisolone has been proposed because an autoimmune reaction
129
what is the success rate in hoof canker?
75-86% with recurrence higher than 50%
130
Minrealization of collateral cartilages is common radiographic finding in.. (mention type of horse and FL or HL)
heavy horses - FL
131
predisposing factors of mineralization of the collateral cartilages
normal aging process, and factors such as heavy body weight, working on hard surfaces, repetitive concussion, poor conformation, improper shoeing or trimming, and other foot problems, including collateral ligament or distal phalangeal injuries
132
does mineralization of collateral cartilages has predisposition?
yes, in mares
133
what is more common mineralized? lateral or medial collateral cartilage?
lateral
134
What is the optimal radiografic views for diagnosis of mineralization of the collateral cartilages of the distal phalanx?
dorsopalmar
The additional use of dorsoproximal-palmarodistal oblique and flexed dorsolateral-palmaromedial oblique and flexed dorsomedial-palmarolateral oblique images (flexed oblique images) are very valuable for the complete evaluation
135
is it possible to confuse in case of ungular cartilage ossification with fracture?
yes. Because separate centers of ossification exist in these cartilages, these findings should not be confused with fractured side bones (Figure 91-37), although in some cases the side bone can fracture (Figure 91-38).
136
Fractures of ossified cartilages are more common where?
Fractures are most common in feet with cartilages with an ossification grade of 4 or 5 (scale 0–5)
137
What are the clinical signs
138
MRI studies showed that ossified ungular cartilages may lead to
MRI studies showed that ossified ungular cartilages may lead to fracture of the palmar process of the distal phalanx and injury of the ungular cartilage ligaments.
139
How can you diagnose?
Ossification of the collateral cartilages is most often an incidental finding.
- Lameness on hard surface
- Digital manipulation of the collateral cartilages can reveal loss of pliability and elicit a pain response
-pain on the ipsilateral aspect of the distal phalanx, injury of the chondrocoronal or chondrosesamoidean ligaments and desmopathy of the collateral ligaments of the DIP joint
- palamr digital nerve block on the side correspondent
140
what is the treatment of cartilage ossificiation
1. Rest in stall or small paddock 2 . 8-12weeks
3. NSAIDS
4. Foot imablances correction - breakover moved caudad
5. Neurectomy in refractory cases
6. Small fragments can be removed with 1-2cm incision parallel to the palmar or plantar aspect of the coronary band
140
should large fragments resultant from fracture of the collateral cartilages be removed?
No it should not be attempeted
141
Quittor is
infection and necrosis of the collateral cartilage (mixed bacterial infection with necrosis)
141
Figure 91-38. Oblique radiographic projection of the distal phalanx of an Arabian horse with a 6-month-old fracture of the medial side bone. Healing is progressing but the fracture line (arrow) is still visible.
141
142
what is the clinical sign of quitor
uncommon condition characterized by intermittent purulent discharge and sinus tract formation at or proximal to the coronary band in proximity to the collateral cartilage
These lesions are chronic and do not heal
143
can be quittor secondary to a penetrating wound of the sole?
yes. Quittor can develop secondary to a penetrating wound of the sole where infection has gained access to the collateral
cartilage.
144
What are the clinical signs of quittor?
C
linical signs of quittor include enlargement over the affected collateral cartilage with one or more chronic sinus tracts that continue to drain.
145
what is the differential diagnosis of quittor?
The most important differential diagnosis is chronic ascending infection of the white line that breaks and drains at or slightly proximal to the coronary band.
146
How do you diagnose quittor?
by observation of the chronic sinus and radiography can aid in case of foreign bodie - contrast medium can be applied
147
What is the treatment of quittor?
First clipp, hoof trimm and rap and rub with povidone iodine soaked bandage for 24 hores before surgical debridement
Local anesth
tourniquet
better to perform in maximal extension to avoid penetration into DIP by accident
A slightly curved incision beginning just dorsal to the coronary band over the diseased collateral cartilage is made (Figure 91-39). The flap is dissected distad to expose the collateral cartilage, and a probe is used to identify the draining tract. Alternatively, diluted methylene blue can be injected into the tract to identify it during dissection
Remove necrotic cartilage
After débridement, the defect is closed with 2-0 monofilament absorbable suture material in a simple interrupted pattern. Injection of 250–500 mg of amikacin into the joint prevents infection. If necrotic cartilage extends distad to or below the coronary band, a hole is drilled into the hoof wall over the ventral-most limits of the excised cartilage to provide drainage (see Figure 91-39)
148
Figure 91-39. Illustration showing the surgical treatment for quittor, also known as necrosis of the collateral cartilage. A hole must be drilled into the hoof wall for adequate drainage if infection and necrosis extend distally to the coronary band. (A) The dotted line represents the surgical incision line. (B) A slightly curved incision beginning just dorsal to the coronary band over the diseased collateral cartilage produces a skin flap that allows removal of the proximal part of the necrotic cartilage.
Change bandage daily followed by short limb cast 8-10 once infection is controlled
149
Prognosis for quittor - conservative management and surgical
Prognosis with conservative management is poor, but with effective surgical treatment including surgical removal of all infected and devitalized cartilage and regional perfusion of antimicrobials, a favorable outcome can be expected
150
fractures within hoof region are divided into 2 types, name them
fractures of distal phalanx
fractures of the distal sesamoid bone
151
what are the causes of distal phalanx fracture?
acute trauma
152
what is more commonly affected by fractures of the distal phalanx the FL or HL?
Fl are more commonly involved
153
How many types of fractures?
I. Abaxial/paramedian fractures without joint involvement
II. Abaxial/paramedian fractures with joint involvement
III. Axial and periaxial fractures with joint involvement
IV. Fractures of the extensor process
V. Multifragment (comminuted) fractures with joint involvement
VI. Solar margin fractures (AUER)
VII. Solar margin fractures in foals (Nixon)
154
Clinical signs of distal phalanx fracture
-severly lame/acute
- hoof warm to the touch
-increased pulse can be palpated
- positive hoof testers
-arthrocentesis of DIP joint results in a sample of blood-tinged synovial fluid
155
What is in the differential diagnosis of distal phalanx fracture
hoof abcess
156
How do you confirm diagnosis of distal phalanx fracture?
Radiography
157
What are the most difficult type of P3fractures to ID in radiographs ?
Abaxial nonarticular fractures are usually difficult to recognize because they are normally only minimally
displaced.
158
Name the radiographic projections
lateromedial,
dorsopalmar
dorso-65-degree proximal-palmarodistal oblique views,
- especially for type 1 or 2 fractures: dorso-45-degree proximal-45-degree lateral-palmarodistal oblique/
dorso-45-degree proximal-45-degree medial-palmarodistal oblique radiographic view, palmaro-45-degree proximal-45-
degree lateral-dorsodistal oblique/palmaro-45-degree proximal-45-degree medial-dorsodistal oblique radiographic view, and palmaroproximal-palmarodistal oblique radiographic view.
159
If fractures are not confirmed in radiographs how much time should be the horse confined to box stall?
7-10 days
160
Beside radiographs which other techniques can be used to diagnose distal phalanx fractures?
Scintigraphy, CT, and MRI are often successful in delineating an obscure fracture (see Chapters 70 to 72).68,81–
161
What is the prognosis of fractures
poor prognosis when the fracture is displaced and intrarticular
162
What are the treatment options for distal phalanx fractures?
Fragment removal
cast application
special shoeing
compression screw fixation
neurectomy
163
What is the surgical treatmetn for intra-articular fractures type II and type III?
Fixation using lag screw tx
164
Figure 91-40. Illustration showing the classification of distal phalangeal fractures: I, Abaxial nonarticular fracture; II, abaxial articular fracture; III, axial and periaxial articular fracture; IV, extensor process fracture; V, multifragment articular fracture; VI, solar margin fractu
165
Figure 91-41. Illustration showing a bar shoe with large side clips to limit hoof expansion laterally during weight bearing. This shoe is often used after hoof wall resection is carried out to access the interior of the hoof capsule, as well as for pedal bone fractures.
166
what is the conservative treatment in distal phalanx fracture?
shoeing or casting technqiues
foals are best treated with stall rest
167
describe the tx of type I fracture - ABAXIAL FRACTURES WITHOUT JOINT
INVOLVEMENT
Application of a fiberglass cast around the hoof capsule is used to provide support for 2 months. The sole must be filled with silicone or polyurethane or bar shoe with large side clips applied to the hoof (figure91-41)
Stall rest 2-4months
NSAIDS
168
How much after initial tx for fractures type I can the horse be riden?
after 4 months, the horse can be ridden at a walk on level ground using regular shoes. The workload is gradually increased according to comfort level
169
what is the prognosis for type I fractue?
has a reasonable prognosis for return to athletic function.84,87,88 It usually takes 4 to 6 months for the fracture to heal. However, radiographically the fracture line is visible for much longer. Initially a fibrous union develops, which ossifies at 6 to 12 months. In some cases, a delayed, malunion or nonunion develops (Figure 91-43).
170
Figure 91-43. Slightly oblique view of a slightly displaced abaxial fracture of the distal phalanx with joint involvement 6 weeks after fracture occurrence. Displacement of the fracture is easily recognized at the palmar articular edge (arrow).
171
Figure 91-42. (A) Palmaro-45-degree proximal-45-degree lateral-dorsodistal oblique radiographic view of a lateral Type I fracture of the pedal bone 2 days after fracture occurrence. (B) Palmaro-45-degree proximal-45-degree lateral-dorsodistal oblique radiographic view of a lateral Type I fracture of the pedal bone 2 months after fracture occurrence.
172
what is the 2 types of treatment of AXIAL, PERIAXIAL, AND ABAXIAL FRACTURES WITH JOINT INVOLVEMENT (TYPES II AND III)
Types II and III fractures may be managed conservatively or surgically, but there is ongoing debate as to whether surgical treatment is superior to conservative management
173
describe the conservative maanagement of types II and III
Conservative management is essentially the same as that described for type I fractures, but it is important to prolong the rest period: As a rule of thumb, the horse is restricted to a box stall for 4 months and initially a cast is applied and later replaced with an orthopedic bar shoe with additional and/or enlarged side clips. followed by 2 months of hand walking followed by 2 months of exercise under saddle at a walk.
174
describe surgical tx for IAL, PERIAXIAL, AND ABAXIAL FRACTURES WITH JOINT INVOLVEMENT (TYPES II AND III)
175
what is the prognosis of conservative tx of type II and type III distal phalanx fracture?
prognosis to return to athletic function is:
- guarded if older than 3 years
- good if less than2 years
176
Figure 91-44. (A) Radiograph of a Type II pedal bone fracture 4 days after fracture occurrence.
(B) Radiograph of a Type II pedal bone fracture 12 months after fracture occurrence; there is delayed union and malunion. Frequently, a delayed union, malunion or nonunion with chronic lameness can be observed after conservative therapy (Figure 91-44).
177
Describe surgical approach to type II and type III fractures
the location of the screws is crucial
use of advanced imaging techniques is required for this choice of treatment
screw must not penetrate the joint
screw must not compromise the solar canal or the insertion of the DDFT
screw size and screw positioning had an influence on stability:
5.5-mm cortex screws were more effective
178
In Type III fractures, it is recommended that screws be inserted from the lateral/medial__________(choose) side because this makes screw removal in the standing horse easier.
Type III fractures, it is recommended that screws be inserted from the lateral side because this makes screw removal in the standing horse easier.
179
describe surgical approach in type II distal phalanx fracture
In **Type II** fractures, the cortical screw is inserted dorsally. It is easier to drill from the large fragment—**dorsally**—toward the small fragment (i.e., i**n a dorsal-to-palmar/plantar direction**).
180
what is mandatory as preparation for surgery in type II and type III fracture?
On the day before surgery, the entire hoof is thoroughly cleaned, the sole trimmed, and all crevices removed. The entire hoof wall surface is rasped and the foot is wrapped in a bandage soaked with a povidone-iodine (Betadine) solution overnight.
181
For surgery of foot fracture the animal is anesthetized and positioned in LR with affected limb uppermost with exception of which type of fracture?
Type II fracture where a small fragment should be placed downward
182
Fractures in the foot have to be perfomed with indispensable prerequisite, what is it?
C-arm, CT machine and or computer assited techniques - authors prefer CT
183
Describe in detail the preparation of the leg in the table
The opposite leg must be tied back so that it does not interfere with the gantry when CT imaging is used. It is also important that the limb be positioned in a way that allows access of the instruments throughout the procedure. When using a C-arm or CT, the leg must be secured in an unequivocally stable position. It is therefore fixed far proximally on a leg support, and two holes are drilled in the hoof capsule so that it can be fixed with a wire to an x-ray block, which is secured to the surgery table with adhesive tape (Figure 91-45,A). Positioning and fixation of the leg in a straight and horizontal line is important and allows images to be taken regularly during the operation without having to move the C-arm. It is very important to recognize that most often the upper leg in lateral recumbency has an outward rotation. So, it is very useful to take several lateromedial and dorsopalmar/-plantar images before surgery to determine the degree of rotation of the leg on the surgery table.
184
In case of CT scan you don't use markers or cannulas or radiographic paste to mark the position on the hoof wall, you use _________ _____________(2w) instead
aiming device
184
You use the arthroscope in the DIP joint (dorsalpouch) for anatomical reduction of the type ____ and some Type fragments can be monitored
With the aid of an arthroscope positioned in the dorsal pouch of the DIP joint, anatomical reduction of the **Type III** and some** Type II **fragments can be monitored
185
What should be avoided in the case of fracture fixation in distal hoof? (3 things)
avoid the coffin joint
and semilunar canal
and placement of the screw too far dorsally.
186
Name the different layers of the hoof capsule to which the surgeon feels the difference as it drills
When an operation involves the hoof capsule, the transitions from horn to corium and from corium to bone usually are readily recognized by the surgeon during drilling as each tissue feels different as it is penetrated.
187
Describe in detail the placement of the screw in the cis and trans fragment of the distal phalanx
GA - LR - limb uppermost
**4.5-mm glide hole** is first drilled through the **horn capsule** and **rinsed** thoroughly (Figure 91-48, A).
The drill bit is then changed to **drill a 4.5-mm hole** into **the cis fragment** of the bone (see Figure 91-48, B), the **aiming device is removed**, the **drill guide** is inserted into the **glide hole,** and the **3.2-mm thread hole** is drilled into the **trans fragment** (see Figure 91-48, C). **Direct measurement of the hole length is not possible because the measuring device cannot be introduced through the glide hole into the horn capsule**, and therefore the screw length is based on CT measurements. The **thread hole is tapped by hand** (see Figure 91-48, D). The **diameter of the hole in the near hoof wall is enlarged to 8 mm** using a **5.5-, 6.0-, 7.0-, and finally 8.0-mm drill bit** in succession, being careful not to drill too deep (see Figure 91-48, E). The **countersink** is then introduced and **rotated 180 to 360 degrees **to create an **optimum seat for the screw head**. The **hole is rinsed** with copious amounts of saline solution; the screw is inserted and solidly tightened. The **correct screw length is confirmed using CT or radiography** (see Figure 91-48, F).
188
Figure 91-45. Preparation of the hoof for fixation of a pedal bone fracture. (A) The leg must be fixed in a stable horizontal position. (B) Illustration showing how the leg must be positioned. (C) Draping of the hoof for surgery.
189
Some authors use a different method for inserting the cortical screw in a lag fashion in the distal phalanx. First, an 8-mm hole is drilled in the hoof wall, and what comes next?
then using an **8- to 10-mm diameter drill bit, a hole is prepared through the hoof capsule** parallel to the sole surface and aligned with the bulbs of the heel. The hole is continued until the drill bit **reaches the distal phalanx**. A **pilot hole is drilled into the distal phalanx** with **a 2-mm drill bit** until it crosses the fracture.** This depth usually cannot be determined without the aid of fluoroscopy or intraoperative radiography**. When the desired location and direction of the drill bit are determined,** the glide hole is prepared**. Frequent fluoroscopic or CT views will help identify the moment when the drill bit crosses the fracture plane. The remaining steps are logical for the screw insertion and do not require further explanation.
190
Figure 91-46. Arthroscopic view of a displaced axial fracture of the distal phalanx via a dorsal approach. Anatomical reduction of the fragments can be directly observed and adjusted if necessary by repositioning of the pointed reduction clamps.
191
192
the hole of hoof capsule can be filled with
The hole in the hoof capsule can be filled with an antibiotic-soaked sponge placed under an aseptic pressure bandage or closed with antibiotic-impregnated PMMA.
193
antibiotic soaked sponge that is placed in the 8mm hole can stay in place for how long?
The bandage is changed after 2 weeks and the antibiotic-soaked sponge is replaced with another, which can be removed after 2 more
weeks.
194
What is the postoperative care of distal phalax fracture? name the months of rest
Postoperative care entails stall rest for 2 months followed by hand walking for another 2 months
195
fracture healing of the distal phalanx is expected in how much time?
Fracture healing can be expected 6 to 10 months postoperatively.
196
what is the prognosis for return to athletic use in distal phalanx fracture?
guarded to good
197
what are the 2 main complications in the postoperative moment of distal phalanx repair?
infection
abcess formation around the screw head
198
199
Figure 91-48 cont'd (G and H) Illustrations of the technique of an axial articular pedal bone fracture repair.
Figure
200
Figure 91-49. (A) Dorsal-65-degree proximal-palmarodistal oblique radiographic view of a parasagittal pedal bone fracture. (B) Location of the first screw. (C) Location of the second screw. (D) Dorsal-65-proximal-palmarodistal oblique radiographic view of the parasagittal bone fracture after surgery.
201
EXTENSOR PROCESS FRAGMENTS (TYPE IV) causea
hyperextension injury,
avulsion injury (fragment pulled away by the extensor tendon),
and a separate center of ossification (osteochondrosis, which may be bilateral)
202
EXTENSOR PROCESS FRAGMENTS (TYPE IV)
some no clinical signs
presence of a fragment of the extensor process is found incidentally.
make local and intraarticular anesthesia
radiographs
203
EXTENSOR PROCESS FRAGMENTS (TYPE IV) in case of being small what is the treatment? and why is important?
Small fragments (see Figure 91-50) should always be removed because they are mobile, cannot be fixed back into place, and have contact with the articular surfaces. Fragment removal is accomplished by routine arthroscopy (Figure 91-51).
204
What is the postoperative treatment? bandage time and horse rest?
bandaged for 3 weeks and the horse is rested for 6 to 8 weeks.
205
what is the short term prognosis?
resolution of lameness is good, but a more guarded prognosis for long-term soundness has been reported
206
E) Postmortem view of the surgically fixed pedal bone after removal of the hoof capsule and soft tissue. This horse was euthanized 6 weeks after the surgical fixation of the pedal bone fracture because of a femur fracture.
207
Figure 91-51. Arthroscopic view of a fractured extensor process (a). The arrow indicates the fragment.
208
Figure 91-50. (A) Preoperative lateromedial radiographic view of an extensor process fracture. (B) Postoperative lateromedial radiographic view of the same horse after removal of the fracture fragment
209
Type IV distal phalanx fractures should be stabilized how?
with aiad of 3.5-4.5 mm cortex screw in lag fashion (Fig 91-52)
210
is conservative tx an option in fractures type IV of distal phalanx?
no, because conservative treatment is often associated with complications such as dislocation of the fragment and nonunion (Figure 91-53).
211
Figure 91-52. (A) Lateromedial radiographic view of a fractured extensor process. (B) Fixation of the fracture with a 4.5-mm cortex screw applied in lag fashion.
212
Figure 91-53. (A) Lateromedial radiographic view of a fractured extensor process of the pedal bone.
(B) Conservative treatment of the fracture with a cast was unsuccessful and resulted in dislocation of the fragment.
Figure
213
Figure 91-54. Lateromedial radiographic view of a large fragment of the extensor process in a 3-year-old Friesian horse.
214
How can you remove the fragment in type IV fracture is too big?
reduce to small pieces using an osteotome and remove piece by piece
214
what is the posteoperative management of large fragments in type IV?
Postoperative a fiberglass cast should be applied to the surgical site
215
what is the long-term outcome?
good
216
Multifragment fractures type V radiographically are...
several fracture lines (Fig 91-55)
217
218
What is the treatment for multifragments type V?
1) Application of a fiberglass cast can be attempted, but these fractures have a poor prognosis for future soundness.
2) If the DIP joint can be surgically reconstructed and stabilized, surgery involving cortex screws in lag fashion should be attempted (see Figure 91-55).
3) Alternatively, a neurectomy can be carried out if euthanasia is not an option
218
Type VI fractures of the distal phalanx are
solar margin fractures
219
A high prevalence of type VI fracture was observed in (name the breed)
Thoroughbred foals associated with front hoof conformation
220
type VI solar margin fractures is associated to what?
1. front hoof conformation in foals
2. kicks a hard immobile object
3. frewwing that produces hard surfaces in the morning
4. chronic laminitis
221
are type VI distal phalanx fractures common in certain geographic regions?
yes, in some geographic regions, these fractures are at risk of occurring in the spring of the year when freezing and thawing produces hard uneven ground in the mornings.
222
what is the prognosis fo type VI?
Type VI
fractures that are traumatic in origin have a good to
excellent prognosis because they are small, nonarticular,
and heal well.
223
What is the treatment of type IV distal phalanx fracture?
Bar shoe and pad
224
can type VI fractures lead to sequestra and abcess?
Surgical removal of fragments has been described in individual cases, especially if infection
develops.
VetBooks
225
Fracture of the distal sesamoid are common or rare?
rare
226
Distal sesamoid fractures are more common in forelimbs or hindlimbs?
forelimbs
227
Distal sesamoid fractures can be dividide in how many types?
4:
1) avulsion fractures (distal, proximal, medial or lateral margins)
2) simple complete fractures of the body (sagital, transverse or frontal
3) comminuted fractures complete fractures
4) frontal fractures
228
avulsion fractures of the distal border of the sesamoid are common to be part of
osteoarhtritic syndrome and can be found in conjuction with navicular disease
50% are bilateral
++ common to be lateral
229
simple fractures of the distal sesamoid are usually what type
abaxial, in vertical slightly oblique direction (Fig91-56)
230
Multifragments of the navicular bone was is the diagnosis?
it is rare and has poor prognosis
231
Fractures of frontal plane of distal sesamoid bone are usual or unsual
highly unusual
232
what is the common cause of distal sesamoid fracture?
trauma and result from excessive or repetitive loading through the middle and distal phalanges and the DDFT
233
Figure 91-56. Oxspring view of a mildly displaced axial fracture of the distal sesamoid bone (simple).
234
Figure 15.1 Radiographs of a right front navicular bone lateral parasagittal fracture. (A) Dorsoproximal‐palmarodistal oblique and
(B) palmaroproximal‐palmarodistal skyline views confirm the fracture in two projections. The fracture is less than two weeks old. There is
minimal displacement and the fracture margins are relatively sharply delineated.
235
Figure 15.2 Dorsoproximal‐palmarodistal oblique view of the
right front foot of a three‐year‐old Quarter Horse with foot
lameness. There is a large, separate osseous fragment (arrows) at
the distolateral border of the navicular bone.
236
what is the prognoosis for conservative treatment of navicular fractures?
guarded to poor for return to athletic performance
237
Figure 15.5 Dorsoproximal‐palmarodistal oblique views of both
front feet of a five‐year‐old Warmblood. The horse passed a
prepurchase examination four weeks previously, but had become
slightly lame, especially on circles, as training was gradually
increased. There are parasagittal defects in both navicular bones
with evidence of chronic remodeling. This presentation is strongly
suggestive of multipartite navicular bones.
238
Figure 91-57. Lateromedial radiographic view of a frontal plane fracture (between the arrows) of the distal sesamoid bone.
239
Figure 91-58. Oxspring view of a pathologic fracture of the distal sesamoid bone. Note the large radiolucent area at the center of the fracture (arrow).
240
what are the clinical signs of dital sesamoid fractures?
acute moderate to seve WB lameness
intensive pain when turning
increased pulsation of palmar or plantar arteries
postive to hoof testers
Low palmar nerve block diagnostic
241
which radiographs should be taken for diagnosis of navicular fracture?
lateromedial
palmaroproximal-palmarodistal oblique (skyline)
dorsoproximal-palmaordistal oblique (oxspring)
242
what is the nonsurgical treatment of distal sesamoid fracture?
placement of a fiberglass cast in a extremly flexed position for 6 months (not all horses tolerate)
243
In case of surgery what is the best approach for distal sesamoid fracture?
Surgical fixation
Cortex screw in lag fashion
244
what is the prognosis for nonsurgical management of navicular fracture?
The prognosis for future athletic activity is unfavorable
245
how much time of healing requires the nonsurgical maangement of navicular fragment?
10-12 months
246
Comminuted fractures of navicular have what type of shape?
247
What are the challanges in the placement of cortex screw for navicular fixation?
1. The difficulty lies in correct placement of the screw,
2. avoiding penetration of the DIP joint and the navicular bursa.
248
Describe in detail the surgical approach for fracture fixation of navicular
GA - LA - limb uppermost - mark entry point with fluoroscopy or CT - hoof prepared day before
**4.5 mm cortex screw or 3.5 screw**
**8 mm drill** in the **hoof wall** and then** 8 to 10 mm diameter drill bit a hole is prepared in the hoof capsule **or **directly 4.5 mm hole **and ri**nse thoroughly** in the hoof wall with aiming device
Placement of **drill guide** into the **glide hole** **new 4.5 mm drill bit** into the* cis *fragment
Remove aiming device
Drill guide inserted in g**lide hole
3.2 mm thread hole** is drilled into the *trans* fragment
Direct measurement not possible (CT measurementes)
**Tap** the thread hole
Hoof wall enlarged using 5.5, 6.0, 7.0 and finally 8 mm drill bit in succesion (don't drill too deep).
Countersink introduced and rotated 180-360 degrees to create seat for the screw head
**Rinse copious amunts of saline
**
249
Figure 91-59. (A) Oxspring view of a fracture of the navicular bone. (B) There is complete nonunion of the fracture 6 months later.
250
Figure 91-60. (A) Skyline view of a navicular fracture. (B) Skyline view of navicular bone fracture fixation with a 3.5-mm cortex screw applied in lag fashion. (C) Oxspring view of a navicular bone fracture
fixation with a 3.5-mm cortex screw applied in lag fashion.
251
252
What are the disadvantages of screws 3.5 and 4.5 mm in the navicular bones?
4.5 mm the screw head is too large
3.5 mm cortex screws have been found broke in the cis fragment
253
How much time it take to heal a fracture of navicular?
6-12 months restricted stall rest and hand walking
254
What can happen to the DIP joint after screw fixation of the navicular?
OA of the DIP joint
255
What is the prognosis for navicular fracture fixation?
guarded for athletic use but favorable for pleasure riding
