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wires are prone to migration toward the narrower
region. A small diameter transfixing k-wire can be placed adjacent to the cerclage wire on the narrower side, but this k-wire may encroach upon the IM pin in doing so. Alternatively, a triangular file can be used to etch a very subtle notch in the bone into which the cerclage wire can be tightened; this notch does not need to pass around the entire circumference of the bone and should not be deep into the cortex as this could increase the risk of fracture at this site; instead, the subtle notch need only accept a small portion (~ 5-10%) of the cerclage wire’s thickness at 1 or 2 sites around the bone’s circumference.
Control of Bending with Cerclage Wire Fixation
Cerclage wire is able to contribute to the control of disruptive bending forces assuming perfect anatomic reconstruction of a long oblique or spiral fracture with properly placed wires. Cerclage wire should never
be used without supplemental fixation because its application is, by definition, restricted to the region the of the fracture rather than distributed along the entire length of the bone.
Control of Rotation with Cerclage Wire Fixation
Properly placed cerclage wires provide good rotational stability, at least in the short term. When a long bone
is subjected to repeated cycles of complex loading forces that include concurrent rotation, bending, and compression, the wires will tend to loosen especially when supplementing an IM pin (remember, IM pins really only contribute to bending stability so the cerclage wire is heavily challenged in IM pin + cerclage scenarios). Thus, IM pin + cerclage wire fixation is typically reserved for cases in which rapid bone healing is anticipated (young patients, good soft tissue health, good systemic patient health, etc), the number of cycles of load can be controlled (good patient / pet owner compliance) and the magnitude of the load cycles are not extreme (smaller patients, good compliance, 3 other healthy limbs, etc).
Control of Axial Compression (Axial Collapse) with Cerclage Wire Fixation
Properly placed cerclage wires provide good resistance to axial collapse, at least in the short term. Once again, cerclage wires tend to loosen somewhat rapidly if subjected to repeated cycles of complex loading, especially if they are of larger magnitude (ie, running, jumping, playing, stairs, falling, etc). This tendency to loosen is particularly profound when cerclage wires are used in combination with IM pin fixation because IM pins have no ability resist rotation and compression; thus, the cerclage wires are heavily relied upon with IM pin + wire fixations. Thus, it only makes sense to restrict IM pin + wire fixation to rapidly healing scenarios with a controlled number and magnitude of cyclical loads as described in the paragraph above.
WSV18-0210
SVA FELINE
STATE-OF-THE-ART LECTURE PECULIARITIES OF FELINE HYPERADRENOCORTICISM
R.V. Barrs1
1Sydney School of Veterinary Science, The University of Sydney, NSW 2006
Introduction
Hyperadrenocorticism (HAC) is an important differential diagnosis for cats with diabetes mellitus. While there are similarities to canine HAC there are also key differences. In addition to pituitary dependent (PDH) and adrenal dependent hyperadrenorticism (ADH), sex-steroid producing adrenal tumours cause HAC and are more common in cats than dogs.
Most, but not all cats with HAC have concurrent diabetes mellitus. Up to a third of cats with HAC have extreme skin fragility. Infections of the skin and nail-beds, urinary, respiratory and gastrointestinal tract secondary to cortisol-induced immune-suppression are also common.
Cats also respond differently to dogs to adrenal function tests including ACTH-stimulation and dexamethasone suppression tests.
Approximately 80% of feline HAC cases are due to PDH. Adenomas cause 90% of PDH cases and 50-60% of ADH cases, the rest are carcinomas.
Clinical presentation
HAC occurs in older cats (mean age ~10 years.) There
is no breed predisposition and males are slightly over- represented (54%). Diabetes mellitus occurs concurrently in 80% of cases.
Table 1. Clinical findings from reported cases of feline HAC
Your Singapore, the Tropical Garden City
    Clinical sign
  % cats with this sign
  Polydipsia and polyuria
  81
  Abdominal enlargement (“pot-belly”)
    61
  Polyphagia
  60
  Skin atrophy
   59
  Muscle wasting
    47
  Weight loss
  47
  Lethargy
    41
  Alopecia
  37
  Skin fragility (skin tears)
   32
  Unkempt hair coat
    30
  Weakness/plantigrade stance
  18
  Hepatomegaly
    13
  Weight gain
   12
 About 50% of cats with diabetes mellitus and HAC have insulin resistance, but it is less severe than in cats with hypersomatotropism (acromegaly). Cats
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