Kapitel 72 - Musculoskeletal neoplasia and limb sparing surgery Flashcards
In what area of the bone is osteosarcoma usually located?
Metaphyseal region of long bone
Where are the two most common sites of osteosarcoma in dogs?
The distal metaphysis of the radius and the proximal metaphysis of the humerus
Osteosarcoma of what location have a more favorable prognosis?
Distal Radius
What is the general survival time of osteosarcoma with aggressive local and systemic treatment?
10-12 month
What are the common radiological signs of osteosarcoma?
- cortical lysis
- periosteal reaction
- extension of osteogenesis into adjacent soft tissue
- loss of the fine trabecular pattern of the metaphysis
- areas of fine punctuate lysis, and
- lack of a distinct border between normal and abnormal bone
Which is the most common type of osteosarcoma?
Endosteal (arises from the medullary canal)
What is Jamshidi needle and Michele trephine examples of?
Bone biopsy instruments
Where is the most common site of metastasis of osteosarcomas?
Lungs and other appendicular bone
What is the incidence of metastasis to lymph nodes?
4,4%
Which are the regional lymph nodes of the thoracic and the pelvic limb?
Thoracic: axillary and pre-scapular
Pelvic: popliteal and inguinal
- When does fracture-associated osteosarcoma usually occur?
Usually after 5 years or longer post fracture surgery
(Most frequently in dogs that have had a comminuted fracture with a history of complicated healing, implant loosening, and/or infection)
At what location does fracture-associated osteosarcoma usually occur?
Usually diaphyseal, most frequently, femur, humerus, or tibia
(of large-breed dogs that are older than 7 years)
Where should a bone biopsy be taken from?
The middle of the lesion
Which are good candidates for scapulectomies?
Those in which the proximal part of the scapula is affected, the neoplasm has not extended into surrounding soft tissues and the scapula can be removed with a 2- to 3-cm margin distal to the neoplasm, and the shoulder joint is preserved.
In which cases can a limb-sparing surgery be considered?
a. It can be considered in patient that will not ambulate well with amputation of the limb due to concurrent orthopedic or neurologic disease, the dog’s size in the case of giant breeds, or previous amputation of another limb
b. Best candidates are those with a distal radial neoplasia without a large amount of soft tissue involvement or evidence of pathologic fracture and the neoplasm should involve less than 50% of the length of the radius.
