Bone Pathology Flashcards
What structures/type of tissue forms during the inflammatory phase of bone healing?
Haematoma
Granulation tissue
How long do fractures take to repair in children?
Around half the usual time
What is the difference between complete and incomplete fractures?
Complete is when the whole shaft of a bone is separated
Incomplete is were it isn’t complete separated
What is the underlying cause of osteomalacia?
Vitamin D deficiency
What is a stress fracture?
A fracture caused by repeated low force injuries to a bone
If the ends of a fracture are closely apposed, which stage of repair can be skipped?
The soft callus stage
What are the two effects that bone mets can have on the structure of bone?
Osteolytic
Osteosclerotic
How long is the hard callus stage usually?
Weeks to months
What mechanotransduction?
The ability of osteocytes to sense stresses present in bone
What is pseudo-arthrosis?
Fibrous tissue that forms in a non-union joint in place of proper repair
What are some bones that are commonly affected by avascular necrosis?
Head of femur
Scaphoid
What is the new name for a simple fracture?
Closed fracture
What is a displaced fracture?
When the two ends of a fracture no longer communicate
Which cells of the bone produce ALP (alkaline phosphatase)?
Osteoblasts
What are the goals of treatments intervention with fractures?
Close the gap between fracture ends
Reduce movement
Remove factors that slow healing eg poor blood supply, infection, smoking
What determines the severity of osteoporosis?
Peak bone mass
Resorption - begins >30
What is the pathophysiology of Paget’s disease?
Osteoclasts are over-reactive
Osteoblasts produce more bone
Results in thick, soft cortical bone, rough trabecular bone and ease of fractures
What is a pathological fracture?
When the fracture is due to some underlying pathology eg osteoporosis or mets
How does hyperparathyroidism effect bone cells?
Increases the activity of osteoclasts
What is the new name for a compound fracture?
Open
How long does it take for non-union fractures to heal?
They don’t
What is a comminuted fracture?
When there are more than 2 broken pieces
A butterfly fracture is another name for what type of fracture?
Comminuted
Despite being thicker than normal, why is the hard callus weaker than normal bone?
Because it’s made up of woven bone
How long does the remodelling stage take?
Months to years
What is mal-union?
Healing of a bone in an unacceptable position
What are the 4 stages of bone healing?
Inflammatory phase
Reparative phase
- Soft callus (cartilage is laid down)
- Hard callus (cartilage is replaced by bone)
Remodelling phase - woven bone is remodelled into Haversian systems
How long does a typical upper limb fracture take to repair in a adult?
6-8 weeks
