14.5 (12.5) Orthopedic surgery in the palliation of cancer

Question 1

List FOUR cancers commonly associated with bony mets

Answer 1

◆ breast
◆ kidney
◆ lung
◆ prostate

Not listed in 6th Ed.
◆ thyroid
◆ multiple myeloma

Question 2

List 3 medical consequences / complications of metastatic bone disease

Answer 2

bone pain
Hypercalcemia
Fracture 
spinal instability
spinal cord compression

Question 3

List the two major mechanisms that cause bone pain from bony metastatic disease

Answer 3

mechanical instability at site of osteolclastic bone destruction

tumor cell stimulation of primary sensory afferent nerve fibres. Sensory afferent fibres are abundant within the periosteum and the medullary canal of bones, in close proximity to blood vessels within the haversian canals.

Question 4

A patient presents with bony metastatic disease without any prior knowledge of having malignant disease.

What two types of imaging investigations are required?

Answer 4

Computed tomography (CT) of the chest, abdomen, and pelvis should be used to evaluate the visceral system for a primary site of involvement and/or additional metastases.

A bone scan should also be performed to identify any other skeletal metastases.

Question 5

Are bone mets more frequently in appendicular vs axial bones?

What are the two most common locations of bone mets in appendicular skeleton?

Are pathological fractures more often in appendicular vs axial bones?

Answer 5

Bone Mets more often in axial skeleton

femur and humerus

—-
Fractures more often in appendicular skeleton

Question 6

List 2 cancers that produce primarily osteoblastic lesions.

List 2 cancers that produce predominantly osteolytic lesions.

List 2 cancers the produce mixed lesions.

What type is seen on bone scan?

Answer 6

Osteoblastic - SCLC, Hodgkin lymphoma, prostate cancer, carcinoid, Hodgkin lymphoma or medulloblastoma, POEMS syndrome

Osteolytic - NSCLC, multiple myeloma, renal, melanoma, thyroid, NHL, langherans cell histocytosis

Mixed - breast, GI, most squamous cell cancers

Bone scan - osteoblastic lesions

FS:
OB = ? More aggressively dividing

Question 7

List four overarching goals of orthopedic intervention for bony metastatic disease

Answer 7

decreasing tumour burden
decreasing pain
increase the quality of life
increasing mobility
improving function

~~~

Ultimate goal is weight bearing as tolerated post procedure

Question 8

What part of bone anatomy provides greater resistance to deformity (thus reducing the chance of fracture)?

What gives bone tensile strength? What gives bone compressive strength?

What type (lytic vs blast) of bone met is more likely for fracture?

Answer 8

Cortical (hard) bone has a greater density than trabecullar/cancellous (spongy) bone and a higher resistance to deformation and failure under given stresses
the greater the amount of cortical bone present, the lower is the likelihood of fracture

Collagen provides tensile strength; calcium hydroxyapatite provides most of the compressive strength

Lytic lesions -> Lytic lesions trigger greater removal of both the mineral and organic components of bone, leading to greater losses in strength and stiffness -> increased fracture risk

Blastic lesions do not disturb the mineral content of bone and (disrupt the normal trabecular framework of the cancellous bone) -> a lower likelihood of fracture.

Question 9

List these cancers in terms of propensity for bone healing from greatest to least: breast, myeloma, lung, renal

Answer 9

Myeloma, renal, breast, lung

WP: based on Gainor and Buchert, 1983. 1983!!

FS: think who lives longer

Question 10

What is the most common site of pathologic fracture and why?

Answer 10

The upper extremities have lower stress loads -> lower-extremity lesions more likely to fracture.

The proximal FEMUR -> cortical bone is thin and cancellous bone comprises the bulk of the structural integrity of the bone

Question 11

List types of orthopedic procedures that can be used to manage metastatic bone disease and…

1) vertebral fracture
2) femur fracture
3) joint issues
4) large tumor mass
5) limb can’t be saved

Answer 11

Bone cement
Fixation (plate or intramedullary)

Joint replacement 

Tumor excision
Amputation 

Question 12

List 3 factors relating to bone mets that predict worse life expectancy

Answer 12

Multiple bone involvement

Hypercalcaemia
Hypoalbumin
Low absolute neutrophil count/Anemia 

Parenchymal organ involvement

Question 13

List 3 minimally invasive procedures that can be used to treat bony mets

Answer 13

cryotherapy
radiofrequency ablation
embolization

Question 14

List three medical treatment considerations after surgical management of bone Mets (excluding analgesia and supportive care)

Answer 14

postoperative treatments:
- radiation therapy
- bisphosphonates
- hormone therapy, and/or chemotherapy whenever appropriate

Question 15

List three predictors of impending pathologic fracture

What is this score called

Answer 15

endosteal cortical destruction >50%
functional pain post XRT
cortical defect >2.5mm or diameter of the bone

WP: Sloan Kettering/authors’ criteria for sx in impending path #

FS: UpToDate - Mirels scoring system based on:

1. Type of lesion (lytic worse than blastic)
2. Location of lesion (trochanter worse than lower extremities worsen than upper extremities)
3. Depth of cortical destruction (> 2/3 is the worst)
4. Roar Pain level

TLDR

Question 16

List 4 categories of factors that affect healing post path fracture

Answer 16

Patient:
◆ nutritional status
◆ pre-existing osteoporosis

Fracture:
◆ site of fracture
◆ type of surgical fixation used

Cancer:
◆ type of met (cancer)/histology of lesion

Other treatments:
◆ xrt exposure
◆ active chemo
◆ hormone therapy use