Abnormalities of Bone Flashcards
What are bone abnormalities?
- break in bone
- fractures
What are bone abnormalities?
- break in bone
- fractures
What is an open fracture?
Skin broken because of fracture
What is a closed fracture?
Skin still intact
What are the types of fractures? (9)
- transverse
- displaced
- compression
- spiral
- epiphyseal
- comminuted
- greenstick
- Colles
- Pott’s
What is transverse (closed) fracture?
Break in bone perpendicular to its length
- heals easily
What is displaced fracture?
Bone has broken and moved from place of alignment
- if not healed in correct position, can cause deformity of limb
What is compression fracture?
Break in bone that occurs in vertebrae
- causes it to collapse due to weight of body
- hard to heal to original position
What is spiral fracture?
Caused by twisting force that forms a fracture line around the bone
- heals well
What is epiphyseal fracture?
Fracture around growth plate
- causes abnormal growth, limb deformities
What is comminuted fracture?
Bone has broken into fragments
- very hard to heal due to complex fragments
What is greenstick fracture?
Crack in the bone, not completely fractured
- heals quickly & well
How does a fracture repair?
- hematoma (blood clot) forms
- internal & external callus begins to forms as spongy bone
- bony callus fully formed & replaces dead bone
- bone remodelling occurs overtime
How does a hematoma form?
- Immediately after fracture, extensive bleeding occurs
- overtime large blood clot forms
How does the internal & external callus begin to form?
- network of spongy bone unites the inner edges to form internal callus
- external callus of cartilage & bone stabilises outer edges
- forms in days
What happens after the bone callus has formed?
- external callus replaced by bone
- dead bone replaced
- takes weeks to form
How does bone remodelling occur?
- swelling/deformity marks location of fracture
- this region is remodelled
What is Fibrodysplasia Ossificans Progressiva (FOP)?
- extremely rare disease
- bone forming outside of skeleton (muscle, tendon, ligament) is ossified
- causes loss of mobility
What is osteoporosis?
Porous bones
- decrease in minerals (esp Ca) in bones
- weaker & susceptible to fractures
Where does osteoporosis occur?
Any bone in body but most commonly spine, hips and wrists
Who can be affected by osteoporosis?
- mainly post-menopausal women
- men, younger women & children
What are risk factors of osteoporosis?
- increased age
- gender: female > male
- ethnic origin: caucasian
- family history
- lifestyle
- long-term use of medication affecting bone strength / hormone levels
- hormone-related conditions
What does estrogen cause an increase in?
- calcitonin
- absorption of Ca in intestines
- activity of osteoblasts
What does estrogen cause a decrease in?
- parathyroid hormone
- excretion of Ca in kidney
- osteoclasts
How does the effect of estrogen on calcitonin and parathyroid hormone affect bones?
causes overall decrease in bone resorption/breakdown
How does the effect of estrogen on Ca (in kidneys and intestine) affect bones?
- intestine = increases bone building
- kidney = decreases bone building
- overall increase in bone builidng
How does the effect of estrogen on osteoblasts and osteoclasts affect bones?
- osteoblasts = increases bone building
- osteoclasts = decreases bone resorption
- overall increase in bone building
What does estrogen deficiency cause?
- bone breakdown increases
- bone building decreases
What are age related changes in bone mass?
- bone mass increases with age until mid 20s
- bone mass decreases after 40
What is the difference in bone appearance between a normal bone matrix and osteoporosis?
- osteoporosis has less dense network
- more vulnerable to fracture
How is osteoporosis identified?
dual-energy X-ray absorptiometry (DEXA)
List preventative measures for osteoporosis
- Adequate calcium & vitamin D intake
- Weight bearing exercise
- Assess bone health in woman >50 & in men > 60
- Adequate estrogen in high risk individuals
- Avoid smoking & excess alcohol
- Prevent first fragility fracture / future fractures if already occurred
What is a treatment of osteoporosis?
Bisphosphonates (bone antiresorptive agent)
- inhibits digestion of bone
- by encouraging osteoclasts to undergo apoptosis (cell death)
- thereby slowing bone loss
What is Rickets?
- softening & weakening of bones in children
- due to extreme & prolonged vitamin D deficiency
What is Sarcoma?
- rare cancers
- arise from transformed cells
Where do sarcomas develop?
- bone
- muscle
- nerves
- cartilage
- tendons
- blood vessels
- fatty & fibrous tissues
What is a osteosarcoma?
Most common type of bone cancer, arises in bone.
What is Myeloma?
Cancer of blood cells in bone marrow
- abnormal cells collect in the bone marrow
- forms tumors
