Amputations Flashcards
According to Billas 2022 in Vet Surg, what were 3 factors associated with an increased risk of infection following canine limb amputation?
Use of a bipolar vessel sealing device for muscle transection, procedure classified as other than clean, and amputation performed for infection or traumatic injury.
According to Marconato 2021 in JAVMA, what period between amputation and initiation of chemotherapy for osteosarcoma was associated with improved median survival times?
<5 days (445 days, compared to 239 days for >5 days).
What are contraindications to performing an amputation?
Severe orthopedic or neurologic disease affecting the other limbs, or extreme obesity.
Why is full limb amputation preferred over partial limb amputation?
Leaving excessive length to the limb without use of a prosthesis can lead to pressure sores and result in unnecessary mass that the animal must carry.
What is the benefit of neuromuscular blockade during amputation?
Prevents muscle fasiculations during transection of muscle bellies with electrosurgery.
What are the advantages/disadvantages of complete scapulectomy v. disarticulation of the limb at the shoulder joint for thoracic limb amputation?
Removal of the scapula is faster and easier.
It has been postulated that maintaining the scapula may aid in protection of the thoracic wall, but there is no evidence to support this.
Following partial removal of the thoracic limb the scapula muscles will also atrophy which may predispose to pressure sores over the acromium.
When performing scapulectomy for forequarter amputation, what vessel is located between the latissimus dorsi muscle and deep pectoral muscles?
Lateral thoracic.
The thoracodorsal artery is located on the medial aspect of the muscle.
When performing scapulectomy for forequarter amputation, what vessel is located at the level of the cleidobrachialis muscle?
Cephalic (deep) and omobrachial (superficial) veins.
What lymph nodes should be collected during forequarter amputation for neoplasia?
Axillary and superficial cervical.
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What are the three pelvic limb amputation techniques?
- Disarticulation of the limb at the hip joint.
- Osteotomy of the femur mid-diaphysis.
- Amputation en bloc with acetabulectomy.
What are the advantages/disadvantages of available pelvic limb amputation techniques?
Mid-femoral amputation has been postulated to protect the male genitalia, however function may be slightly worse than disarticulation techniques (due to increased weight of the stump).
Pressure sores can also develop over stumps in some cases.
When is acetabulectomy indicated with pelvic limb amputation?
Osteosarcoma of the femoral head or neck (has been known to cross the hip joint via that ligament of the head of the femur).
At what level is mid-femoral amputation performed?
The junction of the middle and proximal thirds.
What are the anatomic boundaries of the femoral triangle?
Vessels are caudal to the caudal sartorius and cranial to the pectineus. The artery is cranial to the vein.
The femoral artery and vein should ideally be ligated proximal to which major branches during coxofemoral disarticulation?
The superficial circumflex iliac artery and vein and the lateral circumflex femoral artery and vein.
The medial circumflex femoral artery and vein will likely need to be ligated separately as they branch off more proximal.
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What are the differences in post-operative outcome following thoracic and pelvic limb amputation?
Thoracic limb: biomechanical changes to the vertebral column, carpus, and ipsilateral hip and stifle joints. May have more difficulty that pelvic limb amputation patients in initially maintaining balance.
Pelvic limb: increased range of motion in the tarsal joint, cervicothoracic and thoracolumbar vertebral regions, and extension of the lumbosacral vertebral region. May have more difficulty gaining velocity than thoracic limb amputees.
Obesity may effect mobility and stamina post-operative, although the effect of weight on outcome is varied.
What are some complications associated with thoracic or pelvic limb amputation?
Hemorrhage, seroma formation, dehiscence, infection (13% dogs, 4% cats). Seroma might be the most common complication.
Other less common complications include; neuroma formation, cervical disc herniation, phantom pain.
When might partial limb rather than full-limb amputation be appropriate?
Severe orthopedic or neurologic disease, or obesity. Requires use of a prosthesis.
What are the two types of prostheses that can be used following partial limb amputation?
Socket or intraosseous (ITAP).
What are the requirements for socket prostheses in terms of level of amputation?
Can only be used if the amputation is performed distal to the elbow or stifle joint.
Ideally 30% of the radius/ulna or tibia/fibula should be remaining.
What are reported complications associated with use of intraosseous prostheses?
Aseptic loosening, fracture of the prosthesis.
What is partial foot amputation?
Amputation of two adjacent digits en bloc with or without the corresponding metacarpal or metatarsal bones.
If amputation involves the bones of the carpus or tarsus then a full or partial limb amputation is preferred.
What vessels require transection during partial foot amputation?
Dorsal and palmar/plantar common digital arteries and veins.
Dorsal and palmar/plantar metacarpal/metatarsal arteries.
What tendons are transected during partial foot amputation?
Thoracic limb: common and lateral digital extensors dorsally, and tendons of the superficial and deep digital flexors at the palmar aspect.
Pelvic limb: long and lateral digital extensor muscles dorsally, and tendons of the superficial and deep digital flexors at the plantar aspect.
What is the function following partial foot amputation?
Good, even when both weight bearing digits (3 and 4) have been amputated.
What are some indications for tail amputation?
Trauma, paralysis, neoplasia, tail fold pyoderma.
What is the location of ‘high’ tail amputation?
Between the 2nd or 3rd caudal vertebrae.
Care must be taken to preserve which structure during cranial tail amputation?
The rectum. The levator ani and coccygeus muscles require transection from the caudal vertebrae to allow separation of the rectum from the vertebrae.
How many arteries are present in amputation of the cranial 1/3 of the tail?
7 longitudinal arterial trunks. Only the two lateral caudal arteries and the median caudal artery extend to the tip of the tail.
