Ch 72 MSK neoplasia and limb-spare Flashcards

Question

What are the characteristics of a good candidate for a partial scapulectomy?

Answer 1

Proximal scapula effected Has not extended into surrounding soft tissues Can be removed with a 2-3cm distal margin with preservation of the shoulder joint

Answer 2

**partial**: preservation of the acromion process, the acromial head of the deltoideus muscle, and the distal portion of the infraspinatus and supraspinatus muscles > greater stability of the shoulder compared to subtotal **subtotal**: most of the scapula (as far distal as the scapular notch) while preserving the glenoid and the shoulder joint > loss of muscular support result in a greater dorsoventral excursion during weight bearing. scapulectomy, holes can be drilled in the remaining scapula, and muscles can be sutured to their approximate origins or insertions

Answer 3

DFI 210 days MST 246 days suggesting that the biologic behavior of scapular osteosarcoma is similar to that in other appendicular sites

Answer 4

- compartmental resection of the neoplasm with either 2- to 3-cm soft tissue and/or bone margins from the neoplasm, or a compartment of bone or fascia surrounding the neoplasm should be planned for a curative-intent resection. - preoperative preparation for possible blood transfusion is recommended - ensure ID urethra and rectum Sx - medial dissection: preserve sartorius, enicular and superficial circumflex artery, adductor magnus et brevis, gracilis, and pectineus muscles + abdomial muscles, ventral iliac wing exposed, external iliac artery and vein - lateral: skin is elevated proximally to expose the lumbar fascia above the hip joint, between the semitendinosus and ischiocavernosus muscles, staying medial to the sacrotuberous ligament. The muscles of the pelvic diaphragm (levator ani and coccygeus muscles) can remain undisturbed, superfiical gluteal cut - amputation: The limb is removed by an osteotomy of the ilium cranial to the acetabulum or disarticulation of the sacroiliac joint and by pubic osteotomy, medial muscle attachments are incised, lumbosacral plexus - aggressive perioperative pain management is an essential part of this procedure. | tacking the omentum to the incision

Answer 5

- Total hemipelvectomy (from the pubic symphysis to the sacroiliac joint) - Mid to caudal hemipelvectomy (from the pubic symphysis to the ilium just cranial to the acetabulum) - Mid to cranial hemipelvectomy (from the sacroiliac joint to just caudal to the acetabulum) - Caudal hemipelvectomy (pubic symphysis to just caudal to the acetabulum and allows for limb preservation) | total vs subtotal

Answer 6

infrequent complications, usually minor, hemorrhage main intra-op complication, abdominal wall herniation 1 dog - MST: HSA 179 days, chondrosarcoma 1232d, OSA 533d, STS 373d - MDFI for local recurrence overall 257 days - cats → 75% 1-year survival – higher than dogs

Answer 7

The sartorius muscle Synthetic mesh Medial thigh musculature (gracilus, adductor)

Answer 8

- Oblak and Boston - removal of the ischium with limb preservation. - ventraL: adductor, gracilis, and pectineus muscles) are dissected to be later reattached - Lateral: biceps femoris muscle is tagged with suture for later reattachment. The sciatic nerve preserved. The semimembranosus and semitendinosus muscles are incised distal to their origin. sacrotuberous ligament is incised.

Answer 9

- Cortical allograft (out of favour) - Endoprosthesis - Pasteurised Autograft (65C for 40min) - Vascularised Ulnar Transposition - Bone transport osteogenesis (Distraction osteogenesis) - Irradiated Autograft (not recommended) - Stereotactic Radiosurgery (high risk of fracture 63%)

Answer 10

- patient will not ambulate well with amputation of the limb (concurrent orthopedic or neurologic disease, the dog's size) - ideal candidate: distal radius, do not have a large amount of soft tissue involvement or evidence of pathologic fracture (to reduce recurrence) - neoplasm should involve **less than 50% of the length of the radius** to reduce failure rate

Answer 11

- 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.

Answer 12

- VOI: coated with hydroxyapatite to encourage bone ingrowth, and the screws are locking - BioMedtrix (tantulum) trabecular metal. It is highly fatigue resistant - Fitzpatrick Referrals - failure involving the proximal screws | Charles Kuntz developed the original endoprosthesis

Answer 13

radial segment is removed and cleared of surrounding soft tissues. Neoplastic cells are killed by pasteurization in sterile saline at 65°C for 40 minute - orticocancellous bone graft - similar complications to allograft: local recurrence, infection, and implant failure. - risk for implant failure may be slightly greater because of preexisting lysis of diseased bone - autograft will eventually heal to the osteotomy site

Answer 14

- ipsilateral distal ulna as a vascular rollover graft to replace the defect - no neoplastic involvement of the ulna in utilizing this technique - caudal interosseous artery and vein are preserved - graft heals to the radius and intermedioradial carpal bone - vascularized graft, it is much more resistant to infection. - mild limb shortenting - ulnar transposition is biomechanically weaker than a cortical allograft.

Answer 15

Lateral manus translation

Answer 16

regeneration in which new bone is formed between bony surfaces that are gradually pulled apart. The process relies on progressive, gradual, and prolonged distraction. The new bone, termed regenerate bone, remodels into lamellar bone in a process similar to intramembranous ossification - additional transport segment is osteotomized from the radius proximal - five-ring circular external skeletal fixator - begins 3 to 7 days postoperatively. The transport segment is distracted at a rate of 1 mm total per day - Radiographs of regenerate bone are taken every 10 to 14 days to ensure that the regenerate bone is progressing well - Once the transport segment is within 5 mm of the intermedioradial carpal bone, a cancellous bone graft is inserted - time until docking was 123 days. The mean time until external skeletal fixator removal was 205 days. - regenerate bone is highly resistant to infection - labor intensive for both the owner

Answer 17

- implant failure, local recurrence of an anaplastic sarcoma, and infection. - complication unique to this technique was collapse of the articular cartilage and the subchondral bone of the distal radius - 69%) with deep infection, fracture of the irradiated bone, - Because stereotactic radiosurgery has now become available > no longer recommended

Answer 18

- single dose of radiation accurately delivered to the bone neoplasm, with minimal radiation delivered to surrounding tissues - creating a frame around the limb using pins, inserted into the bone at a site distant to the neoplasm, that fix the fiducial array near the target. This fixation ensured accurate positioning during the planning CT and the delivery of radiation. - linear accelerator, 30 Gy - most useful for small neoplasms with limited bone destruction. - fracture 29 of 46 dogs (63%), recurrence - amp recommended as revision rather than plating (very high fai/infection rate)

Answer 19

- No attempt is made to maintain the function of the extensor muscles and tendons, and soft tissues that are involved in the neoplasm capsule are resected en bloc with the neoplasm, with a minimum 2- to 3-cm margin - An osteotomy of the radius is performed a minimum of 3 cm from the proximal extent of the neoplasm (or endoprosthesis length) - Antebrachiocarpal joint flexion will facilitate disarticulation. - preservation of the blood supply as much as possible. The distal part of the radius is examined for evidence of fracture or neoplasm breakthrough. - The medial cortex of the ulna is removed with the radius. - emove the articular cartilage from the proximal surface of the intermedioradial carpal and ulnar carpal bones - specimen radiograph should be taken and viewed intraoperatively to assess the proximal margin - long (18 to 24 hole) 3.5 mm broad dynamic compression plate, or locking plate,

Answer 20

cadaver limbs, demonstrated that there is no biomechanical advantage to preserving the ulna when an allograft or an endoprosthesis is used for limb-sparing surgery

Answer 21

- Because of potential vascular compromise, large implants, dead space, and high rate of postoperative infection, perioperative antibiotic use is recommended for limb-sparing procedure - multimodal pain relief approach (plexus block, fentanyl, nsaid - An increased risk for implant failure with repetitive percussive activity (contruct strength loss with endoprosthesis and allograft) - Chemotherapy administration can start at the time of suture removal - radiographic monitoring (q 3mths for limb and chest mets)

Answer 22

- infection (difficult to manage because of the relative lack of blood supply and implant, life-long abs or antibiotic-impregnated beads) - recurrence (capsule of the neoplasm is disrupted intraoperatively, OPLA-Pt sustained release of cisplatin may help) - implant failure (endoprosthess proximal) - 20% of the dogs in one study having a subsequent amputation | managed with amputation

Answer 23

Overall complications are very high - post-op infection 40-75% - risk of recurrence (25%) - implant failure (40%)

Answer 24

- diaphyseal location - cortical allograft, pasteurized autograft, extracorporeal intraoperative radiation autograft - overall complication rate was 31.3%, and implant failure (25%)

Answer 25

- reconstruction of the lateral collateral ligament may be necessary - if gross instability is found at the time of surgery, plate stabilization should be performed (pancarpal arthodesis)

Answer 26

- Intraosseous endoprosthesis after partial amputation - case study: structure of the pores of the tantalum allowed for bone and skin ingrowth into the implant - ITAP: intraosseous transcutaneous amputation prosthesis, and the exoprosthesis (study 4 dogs)

Answer 27

Doxorubicin cisplatin/carboplatin combo (alternating) - MST with amputation alone 4-5mths compared to 10-12m with chemo - single-agent carboplatin → longer DFI (425d) and MST (479d) according to one prospective study - best protocol unknown: four to six doses every 3 weeks carbo | cisplatin - renal toxicosis

Answer 28

palliative: - two to four doses of 8 Gy of coarse, fractionated radiation - goal: to improve QOL and reduce pain - if mets present - risk for pathologic fracture - response rate: 50-90% - short MST Full-course, fractionated, curative-intent radiation not recommended because of the side effects, the duration of course, the lack of survival benefit

Answer 29

stereotactic body radiation therapy - effect: 84% lameness improvement max at median 3w for median 6m - >80% tumour necrosis in 50% of limbs assessed - outcome: 41% subsequent fracture, 21% subsequent amputation - MST 233d - mets did not affect survival - salvage amputation – longer MST (346d vs 202)

Answer 30

Osteoclast inhibitors (therefore decrease the rate of osteolysis) - Pamidronate - Zoledronate - alleviation of pain >4m in 50% of OSA | IV monthly

Answer 31

n=11 dogs with once monthly zoledronate for Stage III OSA - median Stage III specific survival 92d with adverse events in 4/11 - median progression-free survival 28d - limited efficacy as single agent for Stage III OSA

Answer 32

1. amputation alone: MST 103-175d 2. single agent adjunct chemo: mDFI 73-257d, 1y 33-65%, 2y 16-28% 3. dual agent adjunct chemo: mDFI 104-413d 4. palliative RT: 50-93% response, MST 122-313d 5. SRT – pathologic fracture 41% 6. metastatectomy: MST 232d vs 49d 7. metronomic chemo to carboplatin → no benefit 8. immunotherapy may improve survival: Mason 2016

Answer 33

- much lower metastatic rate, with the potential for much longer survival time and possibly even cure with amputation alone - Site distribution was slightly different than that associated with osteosarcoma - 25 dogs with amputation: MST 979 days - pulmonary metastatic rate was 28%, depenedent on tumor grade (50% with grade III) - not known whether chemotherapy is beneficial (can be consdiered if metastatic rate >50%) - chanegling to dx before sx: Chondroblastic osteosarcoma can be diagnosed as chondrosarcoma on incisional biopsy

Answer 34

**Sweet 2019** – n=8 treated with stereotactic radiation - no metastasis at time of SRT - late radiation toxicity 3/8 - local progression 3/8, pulmonary metastasis 2/8 - MST 329d - SRT protocol well-tolerated but short duration of response **Holmes 2019** – n=3 craniectomy + adjuvant definitive radiation therapy - MST 387, 422 and 730 days from surgery, 359, 397 and 677 days from RT

Answer 35

rapid progression to metastasis - reported in appendicular skeleton, mandible and extraskeletal - MST <346d

Answer 36

10% Recommend amputation without chemotherapy as prolonged survival can be expected is wide or radical excision is achieved

Answer 37

- 62% skeletal (50:50 axial vs appendicular) - 38% extraskeletal - Axial carries a worse prognosis > difficulty associated with achieving clean margin - amputation without adjunctive chemotherapy. Staging with thoracic radiographs should be performed before surgery - metastatic rate is much lower compared with canine osteosarcoma, and prolonged survival can be expected

Answer 38

overall metastatic rate 30% - 2y survival 55% - no treatment: 1y survival 25%, - younger age associated with higher risk of local progression

Answer 39

- overall distant metastasis 46.3%, 41.9% after amputation - LN metastasis 3.0%, - local recurrence 9.0% - MST 527 days – not associated with age or tumour location osteosarcoma of the humerus has a particularly high incidence of distant metastasis

Answer 40

Cytokeratin CD18

Answer 41

Histiocytic sarcoma - Rottweilers, Bernese Mt Dog Synovial myxoma - Doberman Pinschers

Answer 42

- large-breed, older dogs - incisional biopsy of affected bone and surrounding soft tissues for histopathology and immunohistochemistry - histologic grade was found to be a significant prognostic indicator - elbow and stifle joints were common sites - Dogs with histiocytic sarcoma had significantly shorter mean survival time (5.3 months) compared synovial cell sarcoma and synovial myxoma. - metastatic rate for histiocytic sarcoma high, 10 of 11 dogs (thus full staging b4 sx) - Synovial myxoma mean survival of these dogs was 30.7 months. - amputation is the recommended treatment for this disease if staging is negative

Answer 43

- Rhabdomyosarcoma - Hemangiosarcoma (highly malignant > subcutaneous and intramuscular)

Answer 44

benign lipoma, infiltrative lipoma, liposarcoma

Answer 45

- benign lipoma with a proclivity for caudal thigh, - between the semimembranosus and semitendinosus muscles. - firm, progressively enlarged thigh - CT scan is useful for both diagnostic and surgical plannin - sciatic nerve must be identified and protected during dissection - excellent prognosis, with complete resolution - no recurrence at a mean follow-up of 17 months. | seroma formation

Answer 46

- locally aggressive and invades adjacent muscle - do not metastasize, - cytologically, indistinguishable from benign lipomas. - histopathology: identify infiltration into the muscle. - CT has been shown to be an excellent modality (fat density) EXCEPT when lipoma is contiguous with the patient's normal adipose tissue - wide or radical excision to achieve local control - recurrence rate is 36%, even with aggressive resection - cytoreductive surgery + adjunctive radiation therapy > MST 40mths

Answer 47

- misdiagnosed as lipomas on cytology - CT: heterogeneous soft tissue opacity, rather than a fat - locally aggressive, with a low incidence of metastasis - median survival time was 694 days - wide exision = longer survival

Answer 48

Subungual (1yr survival of 95% vs 60%)

Answer 49

- 53.5% - 61% malignant - 15.7% - 20% benign, - 19% - 25.5% inflammatory - RADS: Squamous cell carcinoma is more likely than malignant melanoma to cause bone lysis - Staging should be performed (chest and local lymph) - excisional biopsy with whole digit amputation (wide excision) most appropriate approach for malignant - Partial foot amputation (amputation of two consecutive digits, +/- part of metabones) may be required for some - Partial foot amputation is an excellent alternative to full limb amputation - some functional disturbance is expected - Free skin grafting may be necessary in some instances SCS - black-coated dogs, and Labrador Retrievers and Standard Poodles - digital: 22.4% of dogs developed at another site, usually within 1 month - lower mets rate than MM > pulmonary metastasis 8% to 29% MM - MST 1 year - pulomonary mets 50% to 58% - ~ 50% draining lymph node mets at Dx - no mets live longer

Answer 50

- squamous cell carcinoma - malignant melenoma | ddx OSA, mast cell tumor, and various soft tissue sarcomas

Answer 51

- 70.5% malignant - 3.5% benign - 26% inflammatory - squamous cell carcinoma (23.8%), fibrosarcoma (22%), adenocarcinoma osteosarcoma , and hemangiosarcoma - **“lung-digit” syndrome**: metastasis of primary pulmonary neoplasia to the digits (adenocarcinoma), multiple digits were involved, MST 67 days

Answer 52

retrospective. 194 dogs. - qualifying for pulmonary metastasectomy on the basis of < 3 pulmonary nodules visible on thoracic radiographs and a DFI > 275 days (n = 21), a survival advantage was also identified for those that actually received pulmonary metastasectomy MST – metastatectomy: 232d, no metastatectomy 49d - not associated with preceding DFI

Answer 53

Limb salvage with a hemipelvic and proximal femoral endoprosthesis resulted in limb function and survival for 14 months. Clinical significance: Neoplasia involving the bones of the coxofemoral joint traditionally requires hemipelvic resection and pelvic limb amputation. This report provides evidence that limb salvage can result in satisfactory levels of activity

Answer 54

Retrospective case series. Study population: Eighteen client-owned dogs. lateral manus translation for distal radial osteosarcoma - 66.6% complication (10/12 infection, 6/12 biomechanical) - 33.3% recurrence - median DFI 219d, MST 370d with adjuvant chemotherapy

Answer 55

poor long-term survival and high metastatic rate, particularly to the lungs, was observed in our case series. A bimorphic pattern on imaging (radiographs, computed tomography, and MRI) consisting of mineralized and nonmineralized areas ( high-grade sarcomatous component adjacent to a lowgrade chondroid component seen histopathologically)

Answer 56

Results indicated that although treatment with SC infusion of carboplatin was well tolerated, the MST for dogs in the present study was similar to reported MSTs in dogs with appendicular osteosarcoma treated with limb amputation alone we could not recommend this protocol

Answer 57

Retrospective . intermuscular lipomas in the hindlimb of 11 dogs often in close proximity to the femoral artery and vein. All lipomas were marginally excised. some lipomas were intimately associated with the sciatic nerve and some showed infiltration of muscle that could be excised en bloc all between semimembranosus and semitendinosus muscles. 1 recurrence. safely excised with minimal short-term complications, good long-term functional outcome and low likelihood of recurrence

Answer 58

n=6 - tumour necrosis 30-90% with no intra-op or peri-procedural complications - cortical bone and adjacent soft tissue not affected microwaves are used to create an electromagnetic field that forces oscillation and rotation of polar molecules . Oscillations occur at about 2 to 5 billion times per minute. The increased kinetic energy from the oscillations creates heat that is evenly distributed through the tissue and kills tumor cells within the zone of ablation by heating the tissues to greater than 55 C to induce acute coagulative necrosis.2

Answer 59

168 client-owned dogs treated at 9 veterinary oncology centers. Findings indicated that early (within 5 days) initiation of adjuvant chemotherapy after limb amputation was associated with a significant and clinically relevant survival benefit for dogs with appendicular osteosarcoma without distant metastases. low prevalence of chemotherapy- related toxic effects among dogs receiving chemotherapy ≤ 5 days after amputation

Answer 60

After revision surgery in case 1 and with the third-generation implant in case 2, no complications were encountered. Both cats showedminor mechanical restriction of stifle range of motion and good clinical long-term outcome without local tumour recurrence. Conclusion The combination of a femoral endoprosthesis and a TKR prosthesis can be a viable alternative for distal femoral limb salvage in cats.

Answer 61

14 dogs and 4 cats Twelve patients underwent bilateral pelvic limb amputations, 4 underwent bilateral thoracic limb amputations, and 2 had 1 pelvic and 1 contralateral thoracic limb amputated. Five patients had reported complications over the course of the follow-up period, most due to trauma Another important point regarding case selection includes location of amputations, with pelvic limb amputees reporting fewer complications (50% vs 25%) than thoracic limb amputees

Answer 62

This case report is the first to demonstrate that removal of the entire left ischium and both pubic bones with preservation of both hind limbs was well tolerated and had a good clinical outcome in a largebreed dog.

Answer 63

case report Instead of replacing the 6-cm bone defect with an endoprosthesis, the limb was acutely shortened and a carpal arthrodesis plate was applied. infection and metabone fracture note the hyperextension of digits of the right forelimb due to flexor laxity with acute limb shortenin One experimental study found that up to 20% of the femur could be resected in mature dogs without causing lameness. compensate for a limb length discrepancy by adjusting the amount of flexion and extension in the joints bilaterally estimated decrease in limb length of 14% limb lengthening external prosthesis

Answer 64

Conclusion: SSI did not influence the survival of dogs with appendicular OSA treated with amputation and curative-intent treatment.

Answer 65

- 54% metastatic disease, 99% treated surgically, 87% received chemotherapy - MST over 1 year 243d (1-1899) - SSI after limb-sparing sx → improved px - chemotherapy did not influence survival after 1 year and did not prolong survival after the development of pulmonary metastasis - pulmonary metastatectomy and RT did not prolong survival after 1 year

Ch 72 MSK neoplasia and limb-spare Flashcards

(94 cards)