14.5 (12.5) Orthopedic surgery in the palliation of cancer Flashcards
List FOUR cancers commonly associated with bony mets
◆ breast
◆ kidney
◆ lung
◆ prostate
Not listed in 6th Ed.
◆ thyroid
◆ multiple myeloma
List 3 medical consequences / complications of metastatic bone disease
bone pain Hypercalcemia Fracture spinal instability spinal cord compression
List the two major mechanisms that cause bone pain from bony metastatic disease
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.
A patient presents with bony metastatic disease without any prior knowledge of having malignant disease.
What two types of imaging investigations are required?
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.
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?
Bone Mets more often in axial skeleton
femur and humerus
—-
Fractures more often in appendicular skeleton
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?
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
List four overarching goals of orthopedic intervention for bony metastatic disease
decreasing tumour burden
decreasing pain
increase the quality of life
increasing mobility
improving function
~~~
Ultimate goal is weight bearing as tolerated post procedure
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?
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.
List these cancers in terms of propensity for bone healing from greatest to least: breast, myeloma, lung, renal
Myeloma, renal, breast, lung
WP: based on Gainor and Buchert, 1983. 1983!!
FS: think who lives longer
What is the most common site of pathologic fracture and why?
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
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
Bone cement Fixation (plate or intramedullary) Joint replacement Tumor excision Amputation
List 3 factors relating to bone mets that predict worse life expectancy
Multiple bone involvement Hypercalcaemia Hypoalbumin Low absolute neutrophil count/Anemia Parenchymal organ involvement
List 3 minimally invasive procedures that can be used to treat bony mets
cryotherapy
radiofrequency ablation
embolization
List three medical treatment considerations after surgical management of bone Mets (excluding analgesia and supportive care)
postoperative treatments:
- radiation therapy
- bisphosphonates
- hormone therapy, and/or chemotherapy whenever appropriate
List three predictors of impending pathologic fracture
What is this score called
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:
- Type of lesion (lytic worse than blastic)
- Location of lesion (trochanter worse than lower extremities worsen than upper extremities)
- Depth of cortical destruction (> 2/3 is the worst)
- Roar Pain level
TLDR