Amputations Flashcards
what are the 2 MAJOR general indications for amputation?
- pain relief
- avoid self-trauma
what are more specific indications for amputation?
- neoplasia (osteosarc, chrondrosarc, soft tissue sarc, etc.)
- severe trauma
- peripheral nerve problems leading to non-functional limb
- compromised vascular supply
- intractable infection
- severe disability
What is involved in the “pre-operative” evaluation prior to an amputation?
- is an amputation appropriate (communicate with o the reason for amputating, prognosis, etc.)
- is the animal a suitable candidate (pre-op CBC/Chem/UA/Blood Type; xrays of the lesion; diagnosis of the lesion; stage if neoplasia; and work-up any comorbidities)
What are radiographic signs of an aggressive bony lesions?
- osteolysis (cortical, trabecular)
- periosteal reaction (long transition zone)
- soft tissue swelling (ext. of osteogenesis into soft tissue = OSA)
- pathological fractures
how much cortical bone loss needs to be present to see lysis on a radiograph?
40%
what is the best way to get a definitive diagnosis of a bony lesion?
bone biopsy
you can try FNA + cytology first, but biopsy is 80-90% accurate.
Where should you take a bone biopsy from in regard to the bony lesion?
MIDDLE of the lesion!!!!
what is the MOST common primary bone tumor in dogs?
osteosarcoma
esp in older, large/giant breeds
its rare in cats, but is still the most common primary brain tumor for them.
T/F: osteosarcomas are highly malignant in dogs and can be located at any bone site
true!
distal radius and proximal humerus are most common.
what is the most common age for osteosarcoma to appear in dogs?
8-9 years old.
what is MST for osteosarcoma in DOGS with amputation alone versus with amputation + chemo?
amp alone = 3-5 months
amp + chemo = 8-14 months
what is MST for osteosarcoma in CATS with amputation alone versus with amputation + chemo?
amp alone = 1.5-5 yr
chemo is up for debate.
what are the 5 general principles of amputation?
- remove the entire limb (Excess bone length creates extra weight and can cause pressure sores)
- gentle tissue handling
- adequate hemostasis
- analgesia
- thorough wound closure (tension free and eliminated dead space)
T/F: you should only transect the intrinsic muscles during an amputation
false – only extrinsic
if you transect the intrinsic muscles, it prolongs surgery time and increases morbidity.
what is the origin and insertion of the triceps?
origin: caudodistal scapula and medial/lat/caud proximal humerus
insertion: olecranon
Which of the following statements is FALSE about intraoperative technique for an amputation?
A. ligate the artery and the vein separately.
B. double ligate the major vessels
C. always ligate artery first
D. ligate with silk or long lasting absorbable (PDS, Maxon)
C. always ligate artery first
doesnt matter if you ligate artery or vein first.
artery 1st –> prevents loss/pooling of blood in limb
vein 1st –> limit metastatic spread
the femoral artery is the main supply to the hindlimb, what is the femoral artery a continuation of?
external iliac artery
The axillary artery is the main supply of the forelimb, what is the axillary artery a continuation of?
the subclavian artery which is a huge branch directly off of the aorta
what is the difference between electrosurgery and electrocautery?
electrosurgery is an electric current from an instrument moving through tissues. this causes heat, protein denaturation, and tissue dehydration
(good hemostasis, quicker, and decreased pain; buuut increases inflammation and decreases wound healing)
electrocautery does NOT pass a current through the tissues; it transfers energy in the form of heat.