Diseases of the Bones Flashcards
What is xray good for
Bone injuries, easy to visualise cortex
What is CT good for
Pinpoint injuries in bony structures & blood supply
What is MRI good for
Internal structure of bone, tissue differences (abnormal vs normal), inflammation of soft tissue
What is angiography for in metastatic bone disease
To see devascularisation of vascular metastases
What is sclerosis, and what does it look like on an xray
Increased bone density, very white, loss of visible structure
What is the name of the disease where blood supply to a bone has been stopped
Avascular necrosis of bone
What are the types of metastatic bone disease
Diffuse, or focal. Diffuse = uncontrolled osteoblast activity, focal affects cortex or medullary cavity
What is necrosis
Death of bone
What are the types of metastases
osteoblastic, osteolytic, both
Common primary causes of metastases in bone (cancers)
Prostate, breast, lung, kidney
Common originations of osteoblastic (sclerotic) disease
Prostate carcinoma, breast carcinoma, colon carcinoma, bladder, soft tissue sarcoma
What is avascular (aseptic) necrosis
Damage to blood supply that causes bone collapse
What is paget disease
Chronic bone disease, increased bone resorption & formation
Name diseases with decreased bone density (4)
Osteoporosis, hyperparathyroidism, rickets, osteomalacia
What are the symptoms of decreased bone density (4)
No pain in early stages, pathologic fractures, lucency, compression of vertebral bodies
What are the 2 types of osteoporosis
Postmenopausal - osteoclastic activity (less osteoclasts & osteoblasts), Senile - loss of total bone mass
What increases the risk of ostseoporosis
Estrogen deficiency, steroids, alcoholism (less Ca absorption), cushing disease
What are osteoporosis treatments
Drugs to increase bone density & calcium resorption
What is a trabeculae
Tissue element in the middle of the bone that supports it & transfers load away from the cortical bone
What are the 3 forms of hyperparathyroidism (primary, secondary, tertiary)
1- hypercalcemia
2- renal disease
3- autonomous hyper secretion
- hypercalcaemia due to PTH 2. chronic renal disease due to calcium & phosphorous imbalance 3. autonomous hyper-secretion due to long standing secondary hyperparathyroidism
What’s hyperplasia
the enlargement of an organ or tissue caused by an increase in the reproduction rate of its cells, often as an initial stage in the development of cancer.
What is rickets
Loss of bone density caused by lack of vitamin D from diet or lack of exposure in sun. Children will have bones that don’t form properly and can’t bear weight. Growth plates won’t close
What is osteomalacia
Adult version of rickets. Failure to calcify osteoid matrix, often chronic renal disease. Hallmark is pseudofracture
Where on the skeleton is it common to see osteomalacia
iscial rami, metatarsals, calcaneus
Name 3 diseases with focal loss of bone density
metatstatic bone disease, multiple myeloma, osteomyelitis, primary benign tumors
What cancers are commonly associated with osteolytic metastatic bone disease
Prostate, breast, lung, renal, thyroid, lymphoma
What scan identifies metastases in skeletal tissue
Radionuclide bone scan
What is multiple myloma & how is it detected
Proliferation of immune cells in bone marrow, plain radiographs
What is osteomyelitis
Focal destruction of bone by bacterial infection, usually blood borne
How do you differentiate bone tumors
Plain radiology
Where does osteomyelitis usually grow
Growth plate in children, joint space in adults
How do you tell the difference between benign & malignant tumors/ lesion
Benign has well defined border, not spreading, lack of soft tissue match, still one destruction. Malignant looks permeative, interrupted & wide
What is osteoscarcoma
Metaphases of long bones especially distal femur
What is metaphses
Cartilage
What is chondrosarcoma
Metaphysis & diaphysis of long bones including pelvis
Fibrosarcoma?
Soft tissue metaphysis of femur & tibia
What specific parts of the bone get fractured
Diaphysis & epicondyle
What are complications of fractures
Compound (through skin), involvement of joints
What is a complete fracture
Both sides of cortex broken
Incomplete fracture
Soft bone, common in kids, break on one side
Torus/buckle fracture
Compression of cortex
What does torus look like on an x-ray
Small bump on bone
Look at types of fractures in notes
Difference between comminuted & simple fractures
Simple easy to put back together, comminuted is many little pieces and disrupts blood supply as well
Compacted bone fracture
Shaft of the bone goes into head of bone. Only bones like humerus
Transverse fracture
Goes straight across, caused by a bang
Oblique fracture
Angle straight across, landing with weight
Spiral fracture
All around the bone
Stress fracture
Lots of small breaks in the bone that don’t allow it enough time to perform remodelling
Common stress fracture locations
Proximal femur & tibia, calcaneus, 2nd & 3rd metatarsals
Stages of fracture healing
- Inflammatory - haematoma due to vessel damage. Inflammatory response localises the damage (first day)
- Cartilage - Fibrocartilaginous callus formation (within a week), cartliage formation, vascularisation.
- Ossification- Reparative (1-4weeks) can be 6 depending on age & complications. Cartilage is resorbed and replaced by bone (ossification). Clumps of osteoid (matrix) that will start to ossify. Still soft tissue.
- Lamellar- Remodelling stage. Woven bone replaced by lamellar bone. Months to years.
Why are plates & pins added sometimes
To stabilise bone while it heals and avoid non union from excess movement
Factors affecting bone repair
Intact local blood supply - if there is no blood supply it won’t heal & needs to be replaced
Type of fracture - spiral & oblique repair faster than transverse
Fixation - movement slows healing
Age
Concurrent infection, disease, nutrition (lack of Ca in diet)
What is the definition of a repair
Continuity of cortex, no visible fracture line, bone is calcified (4-6 weeks)
What is a callus
Lump around a broken bone
What is a pathologic fracture
One that occurs due to a pre-existing abnormality
What is a dislocation
Bones that formed the joint are no longer in correct contact
What is subluxation
Bones that formed the joint are in partial contact
What is arthritis
Inflammatory condition of joints that almost always causes joint space narrowing
What are the 3 types of arthritis
Osteo - degeneration of joint cartilage
Inflammatory - immune system attacking joint
Septic - immediate treatment due to bacterial infection in joint
What is osteoarthritis –> refer to notes
Hypertrophic arthritis that causes bone formation beyond parent bone
Causes subchondral sclerosis & subchondral cysts
What is rheumatoid arthritis
Erosive arthritis
Causes proliferation of synovial membrane
Erosion of articular cartilage
Soft tissue swelling of affected joints
Deformation of joints
Dry eyes, dry mouth
What does multiple myeloma look like on a radiograph
Multiple lytic lesions that look like soap bubbles
What does osteomyelitis look like on a radiograph
Loss of definition of cortex, gas looking appearance of soft tissues e.g. phalanges
