Hip Dysplasia Flashcards
what are the goals of disease-modifying surgeries (JPS, TPO, DPO) that modify biomechanics and development of growing dogs?
- stop subluxation tendency
- restore hip congruity
- save joint from OA development
when should JPS, TPO, and DPO surgeries be performed?
BEFORE OA progression (which occurs at around 7 months in hips with laxity)
so early diagnosis is key.
when should juvenile pubic symphysiodesis (JPS) surgery be performed?
3-5 months of age
as soon as the diagnosis is reasonable which is 3.5-4 months of age, unless giant breed then 4.5-5 months of age.
what is the goal of the JPS surgery in 3-5 month old dogs?
Induces premature closure of the pubic symphysis by thermal (electrocoagulation) necrosis. When pubic symphyseal growth is arrested, acetabular rotation occurs in such a way that femoral head coverage is improved.
Acetabular angle increases and distraction index decreases. Major goals are to improve joint congruity, decrease hip laxity, and reverse/prevent progression of OA in the hip.
What does PENN Hip assess?
3 radiographs:
1. extended view which assess hip conformation
2. “before” assessing laxity with the distraction index tool
3. “after” assessing laxity with the distraction index tool
scores will be compared to others within the same breed (above/below average or average)
DI can determine risk of developing OA in the future and improve breeding choices (moreso than OFA alone).
What is the interpretation of a positive ortolani sign?
hip laxity is present.
what are the various criteria for JPS indication?
- age – 3.5-4.5 months
- positive ortolani sign
- angle of reduction = 15-40
- angle of subluxation = 0-10
- dorsal acetabular rim angle up to 12
- no dorsal acetabular rim erosion
- distraction index 0.4-0.7
- no clinical signs
where is the incision for JPS made?
just caudal to spay incision
what portion of the pubis are you cauterizing in a JPS?
cranial part (corresponding to the pubic rami)
what are the 5 radiographic changes seen after JPS?
- pubic symphysis fused
- broad and short pubic rami
- widened obturator foramina
- irregular pubic profile
- detectable acetabular fossae
what is the prognosis/outcome of JPS?
JPS is effective in dogs with light-to-moderate early clinical imaging signs of CHD susceptibility
It is ineffective in dogs with more severe clinical and radiographic early signs.
Early diagnosis is required, if clinical signs are present, it is too late.
It is a minimally invasive procedure with low morbidity and few complications.
Owner compliance is mandatory for post-op care (environmental influence).
why is there ethical concern regarding JPS?
Technically you are doing a prophylactic procedure on a currently healthy dog. And, it raises the question whether these dogs should be excluded from breeding.
What is the purpose of the TPO and DPO?
arrest the development of hip dysplasia in early stages of disease.
what is the difference between TPO and DPO?
TPO - osteotomy of ilial body, pubic osteotomy, and ischial osteotomy
DPO - osteotomy of ilial body, pubic osteotomy, NO ischial osteotomy.
why is TPO no longer popular?
- high morbidity for patient
- high incidence of complications (high stress on fixation of ischium and implant loosening)
- pelvic narrowing and excessive head coverage
- increases progress and reliability of total hip replacement