Large Animal Surgery

1
Large Animal Surgery

• Female Urogenital Surgery
• Tendonitis
• OCD
• Arthroscopy

Amy Fayette October 2005
2
What is pneumovagina

• Aspiration of air into the vagina

3
What causes pneumovagina

• Poor conformation
• Injury

4
What sx is done to prevent pneumovagina

• Caslicks

5
Why do you want to performa caslicks

• Prevent vaginitis, cervicitis, metritis,
  infertility and noise production

6
How is a caslicks performed

• 3 mm of tissue is removed from each side of the
  vulva
• The two sides are sutured together with mattress
  sutures

7
What instrument is used

• Scissors

8
What is the most important aftercare instructions
with a caslicks

• Reopen before foaling

9
What are the indications for a perineal body
reconstruction

• Ineffective vulvar and vestibular seal
• Failed caslicks
• Rectovestibular injuries

10
What are the important aftercare instructions for
a perineal body reconstruction

• 4-6 weeks sexual rest
• Episiotomy at foaling

11
What is a perineal body transection used for

• Decrease a forward sloping vulva

12
What are the clinical signs of urovagina

• Vaginitis
• Cervicitis
• Endometritis
• Decreased conception rates

13
What are the causes of urovagina

• Pneumovagina
• Ectopic ureter (very rare)
• Excessive closure of caslicks

14
What surgery is done to prevent urovagina

• Caudal relocation of transverse fold
• Or caudal urethral extension

15
What types of injuries can occur from foaling

• Perineal lacerations
• Rectovestibular fistulae
• Vaginal contusions
• Vaginal rupture
• Cervical lacerations
• Uterine rupture
• Uterine hemorrhage
• Uterine prolapse
• Eversion/prolapse/rupture of the bladder
• GI injuries

16
What is a first degree perineal laceration

• Only mucosa of the vestibule/vulva

17
What is a second degree perineal laceration

• Mucosa and submucosa

18
What is a third degree perineal laceration

• Perineal body, anal sphincter, floor of the rectum

19
What can increase the chances of perineal
laceration

• Primiparous mares
• Fetal malposition
• Nose or foot catching the vulvovaginal fold

20
What is involved in repair of third degree
lacerations

• Local debridement
• Tetanus prophylaxis
• Repair in 4-6 weeks post partum
• Diet change (soft feces)

21
Why is a tracheostomy sometimes used to decrease
the chances of a laceration

• Cant close the epiglottis which decreases the
  pressure mares develop during parturition
• Can still foal normally

22
What are the two methods of rectovestibular repair

• Aanes method (2 stage)
• Goetze or Vaughan method (1 stage)

23
In the staged procedure how long is the period
between each stage

• 2-3 weeks

24
When can breeding occur post op

• 6 weeks

25
What is important to remember as aftercare
instructions

• Episiotomy at foaling

26
What is a rectovestibular fistula

• Laceration of dorsal vestibula into the rectum
  without disruption of the perineal body or anal
  sphincter

27
How should rectovestibular fistulae be repaired

• Small may close spontaneously
• Direct closure via rectum or vestibule

28
Tendons are made out of what type of collagen

• Type 1

29
Other than collagen what else is in tendons

• Glycoproteins (COMP)
• Growth factors

30
What type of growth factors are found in tendons

• BMP
• TGFb
• IGF

31
What are the two ways tendon injuries occur

• Athletic horses overload stress on tendinous
  structures
• Injury from external forces

32
What is the definition of tendonitis

• Disruption or stain of tendon fibers or
  musculocutaneous junction with subsequent
  inflammation

33
What is this called

• Overloading

34
What is the most common site for tendonitis

• SDF tendon at the mid metacarpus

35
What are some other common site for tendonitis

• Distal check ligament
• DDF tendon at the level of the fetlock

36
What are the clinical signs of tendonitis

• Swelling at injury site (acute)
• Pain on palpation
• Reluctance to move
• 3/5 lameness

37
What is the most efficient method to diagnose
tendonitis

• Ultrasound

38
What other techniques are used to diagnose
tendonitis

• Contrast Radiology
• Thermography
• Nuclear scintigraphy
• MRI

39
What are the zones for ultrasound evaluation
40
What is a type 1 lesion

• Diffuse loss of fiber density (hypoechoic)

41
What is a type 2 lesion

• Core lesion that is less than 50 of the cross
  section

42
What is a type 3 lesion

• Core lesion greater than 50 of the cross section

43
What is a type 4 lesion

• Core lesion of the entire cross section

44
What is a bowed tendon

• Tendinitis of the SDF

45
Is a bowed tendon an emergency

• YES

46
What are the most basic treatments for tendonitis

• Cold hydrotherapy
• NSAIDS
• Bandages, casts
• Corrective shoeing
• IV DMSO
• Rest

47
What are some more controversial treatments for
tendonitis

• Sodium hyaluronate
• b-aminopropionitrile
• Growth factors
• Firing
• Bone marrow transplantation

48
What is the most important treatment for
tendonitis

• REST

49
How does BAPN work

• Blocks enzyme lysyl oxidase

50
What is the purpose of tendon splitting

• Improves the extrinsic vascular influx which
  facilitates healing

51
How does a superior check ligament desmotomy aid
in healing from tendonitis

• Remove stress from the SDFT which allows the
  tendon to heal while reducing the stress

52
What is an inferior check ligament desmotomy used
for

• Tx of flexure deformity of the coffin joint

53
What is an annular ligament desmotomy used for

• Tendinitis at the level of the fetlock
• Annular ligament compression elicits pain
• After removing the compression pain is alleviated
  and circulation improves

54
What post op care should be performed for cases
of tendonitis

• Staged controlled exercise
• Repeat ultrasound evaluations
• Return to training after resolution of ultrasound
  lesions
• Tendons injured by overloading are prone to
  reinjury

55
What is the prognosis for extensor tendon
lacerations

• Good

56
What is the prognosis for flexor tendon
lacerations

• Decreased prognosis for return to soundness

57
What is tenosynovitis

• Inflammation of the synovial membrane of the
  tendon sheath

58
What are the clinical signs of tenosynovitis

• Distension of the tendon sheath due to synovial
  effusion
• Localized pain
• Lameness (sometimes non-weight bearing)
• Draining tract

59
Where does septic tenosynovitis most commonly
occur

• Digital flexor tendon

60
How does septic tenosynovitis usually occur

• Extension of local sepsis or direct inoculation
• Hematogenous translocation of bacteria is rare

61
How do you diagnose septic tenosynovitis

• PE
• Synovial fluid analysis
• Contrast rads
• ultrasound

62
What is the treatment for septic tenosynovitis

• Medical???
• Surgical debridement and lavage

63
What is the definition of Osteochondrosis

• Process of abnormal bone and cartilage formation

64
What is the definition of OCD

• Lesions that penetrate the joint surface creating
  inflammation and effusion

65
Bone and cartilage form via the process of
__________

• Endochondral ossification

66
How is bone formed

• Chondrocytes form calcified columns
• Programmed cell death
• Primary spongiosa is formed by osteoblast using
  the calcified columns

67
How does osteochondrosis develop

• Failure of blood vessels to penetrate the
  calcified cartilage and occlusion of canals
  causes epiphyseal necrosis

68
What other things can cause epiphyseal necrosis

• Mechanical shearing
• Stress concentration
• Blunt trauma
• Repeated damage

69
What happens as a result of the failure of blood
vessels to penetrate the calcified cartilage

• Persistence of cartilage
• Formation of cysts
• Formation of fissures and a flap

70
What are the two age groups in which cartilage
defects occur

• Birth- 5 months of age
• Greater than 1 year

71
What is the pathophysiology of osteochondrosis at
a young age

• Thickened cartilage
• Cyst like changes
• Degeneration of cartilage
• Uncalcified cartilage not vascularized
• Cracks in pathological catilage

72
What is the pathophysiology of osteochrondrosis
as an adult

• Subchondral fibrosis
• Fibrocartilage covers the defect
• Sclerosis of subchondral bone
• Osteophyte formation
• Leads to degenerative osteoarthritis

73
Hyaline cartilage is type __

• 2

74
Fibrocartilage is type __

• 1

75
What are the etiologies of osteochondrosis

• Genetics
• Nutrition
• Trauma
• Combination

76
What genetic factors may lead to osteochondrosis

• Heritable trait
• Rapid growth potential
• Twice as common in males vs females

77
What nutritional factors may lead to
osteochondrosis

• Low calcium, high phosphorus
• Trace minerals (excess zinc, copper deficit)
• Vitamin A and D deficiency
• High protein diet
• High caloric intake

78
How lame are horses with osteochondrosis

• Slightly lame

79
What other clinical signs are noted with
osteochondrosis

• Slight decrease in range of motion
• Slight pain on manipulation
• Synovial effusion

80
Is OCD unilateral or bilateral

• Bilateral

81
Why is OCD only slightly painful

• No nerves in cartilage

82
What is the onset of clinical signs

• Insidious to acute

83
How do you diagnose OCD

• Rads
• Also scintigraphy, arthroscopy or MRI

84
What are the most common regions affected with
equine OCD

• 1 Hock
• 2 Stifle

85
What other regions are affected with equine OCD

• Fetlock
• Cervical vertebrae
• Shoulder (rare)

86
What are the most common locations for OCD on the
hock

• Distal intermediate ridge of the talus
• Lateral trochlear ridge
• Medial trochlear ridge

87
What regions on the hock are affected with OCD
but only rarely

• Medial and lateral malleolus

88
Which regions on the stifle are affected with OCD

• Lateral trochlear ridge
• Medial trochlear ridge
• Cyst on the medial femoral condyle

89
What regions on the fetlock are affected with OCD

• Sagittal ridge of MC 3
• Caudal eminence of P1
• P1 or MC3 cyst

90
What is the treatment for OCD

• REST
• Intra-articular meds
• Joint supplements
• Chondroprotective agents
• Surgery (arthroscopy)

91
What are the goals of joint therapy for OCD

• Decreases joint inflammation
• Decreases cartilage degradation
• Decreases pain
• Maintain/improve athletic performance
• Promote longevity
• Improve quality of life

92
What chondroprotective agents can be used

• Glucosamine
• Chondroitin sulfate
• Hyaluronic acid
• Polysulfated glycosamineoglycans (PSGAG)
• Antiinflammatories (NSAIDS, corticosteroids)

93
What is a potential problem with the route of
administration of glucosamine and chondroitan
sulfate

• Give PO may be broken down in the GI and not in
  the joint

94
What are some advanced surgical options beyond
arthroscopy

• Ostochondral dowel grafts
• Autologous chondrocyte transplantation
• Gene therapy

95
What procedure is this

• Osteochondral dowel graft

96
What is autogenous chondrocyte transplantation

• Placement of in vitro cultivated chondrocytes
  under a periosteal flap to allow for
  proliferation of the cells

97
What length arthroscope is most commonly used for
equines

• 4mm

98
Why is one sharp and one blunt

• The sharp one is to go through the soft tissue
• Its replaced later by the blunt one to avoid
  damaging cartilage

99
What is this instrument

• Exploring probe

100
What is this instrument

• Ferris smith rongeurs

101
What is this instrumentwhat is its function

• Eggress cannula
• Flush out debris

102
What should be done in preparation for arthroscopy

• Scrubbing and draping
• Must be done under sterile conditions

103
What can you use to distend the joint with

• LRS, CO2 or glycine

104
Why might you need to make the skin incision
before joint distention

• To properly see the landmarks

105
How big is the average skin incision for
arthroscopy

• lt1 cm long

106
What technique is used to decrease the chances of
missing an area when performing arthroscopy

• Triangulation technique

107
What is wrong with this synovial capsule and what
does it indicate

• Hyperemia
• Indicates inflammation

108
What is wrong with this synovial capsule and what
does it indicate

• Thickened villi
• Chronic disease process

109
What is wrong with this synovial capsule

• Petechiation

What is this instrument?
Eggress cannula
110
What is wrong with this cartilage

• Fibrillation

111
What is wrong with this cartilage

• Erosions/ wear lines

112
What is wrong with this cartilage

• Full thickness defect

113
What is the most common chip fracture of the
carpus

• Distal radial carpal bone

114
What other chip fractures commonly occur in the
carpus

• Proximal intermediate carpal bone
• Distal lateral radius

115
How can third carpal bone fractures be repaired

• Fix with lag screws