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.
List the bone-sparing techniques described
a. Cortical Allograft
b. Endoprosthesis
c. Pasteurized Autograft
d. Bone Transport Osteogenesis
e. Irradiated Autograft
f. Stereotactic Radiosurgery
What are the disadvantages of the cortical allograft limb sparing technique?
high infection rate (approximately 50%) and the fact that the allograft is large and is not incorporated into the host bone within the patient’s remaining life span = large bone sequestrum
(this technique is not really used anymore)
When can chemotherapy be started after a limb sparing procedure?
At the time of suture removal if the surgical incision has healed and no signs of infection.
What are the three major complications after limb sparing surgery?
a. Infection
b. Local recurrence
c. Implant failure
What is the local recurrent rate of limb sparing procedures?
Up to 25%
What is the reported rate of construct failure during limb sparing procedures?
40%
What is the reported survival time of dogs treated with amputation in conjunction with chemotherapy?
Median survival time of 235-320 days
Name some palliative alternatives for management of osteosarcoma
a. Palliative radiation (best option according to author)
b. Chemotherapy, usually with carboplatin or doxorubicin (can be used together with radiations)
c. Biphosphonate (Pamidronate, osteoclast inhibitors), 1-2 mg/kg IV once a month
d. Pain management!!!
Which are the two most common sites for chondrosarcoma in dogs?
Tibia and femur
Chondrosarcoma can be graded 1-3. What is the rate of pulmonary metastasis and median survival time in the different grades?
Grade 1: 0% and 6 years
Grade 2: 31% and 2,7 years
Grade 3: 50% and 0,9 years
What is the metastatic rate for cats with osteosarcoma at the time of presentation?
10% (dvs. Much lower compared to dogs)
What is the recommended treatment for cats with appendicular osteosarcoma?
Amputation without adjunctive chemotherapy.
List possible neoplasia of the joints
a. Synovial cell sarcoma
b. Histocytic sarcoma
c. Synovial myxoma
d. Other sarcomas
What are diagnostic for synovial cell sarcoma?
A histological apperence consistent with synovial cell sarcoma and positive immunohistochemistry staining for cytokeratin.
(although absence of cytokeratin staining does not rule out synovial cell carcinoma)
What breeds are overrepresented for histocytic sarcoma, synovial cell sarcoma and synovial myxoma?
Histocytic sarcoma: Rottweiler and Bernese mountain dogs
Synovial cell sarcoma: Golden retrievers (with elbow and stifle being the most common site)
Synovial myxoma: Doberman Pincher
What are the three types of adipose neoplasia?
Lipoma, infiltrative lipoma and liposarcoma
What is the recurrence rate of infiltrative lipoma even after radical resection?
36%
How can liposarcomas be differentiated from lipomas on CT?
They tend to have a more heterogenous soft tissue opacity rather than fat opacity.
What is the two most common type of neoplasia of the digits in dogs?
Squamous cell carcinoma and malignant melanoma.
(squamous cell carcinoma has a low metastatic rate compared with malignant melanoma)
