Week 5 Fractures/US/Tissue Injury - Hoffman Flashcards
Intramembranous ossificiation
mineralization of connective tissue
Endochondral ossification
mineralization of cartilage
Woven Bone
immature bone
Lamellar Bone
Mature Bone
Where are osteoblasts, chondrocytes, and fibroblasts derived from?
Pluripotent mesenchymal cells
Where are osteoclasts derived from?
Monocytes
Clinical Union
fracture site becomes stable and pain free
Radiographic union
plain radiographs show bone trabeculae or cortical bone crossing the fracture site
In which direction does maturation of the growth plate occur?
distal to proximal
Radiopaque vs. radiolucent
Radiopaque= relative impenetrability to x-rays
Radiolucent- relative penetrability to x-rays
Key principles of x-rays?
An x-ray is only as good as the history and physical exam!
Metaphysis and diaphysis
diaphysis = long shaft Metaphysis = diaphysis to joint
What is a fracture?
a complete disruption in the continuity of a bone = a radiolucent line on x-ray!
What are the indirect signs of a fracture?
- soft-tissue swelling
- obliteration or displacement of fat stripes (pad)
- periosteal and endosteal reaction
- buckling of the cortex
- double cortical line
Advantages of ultra sound?
- High resolution capability
- Portability
- Cost
- real-time
- radiation-free
- Image not degraded by metal
- expands diagnostic capabilities
Define musculoskeletal ultrasound
-use of high frequency sound waves to image soft tissues and bony structures for the purposes of diagnosing pathology or guiding real-time interventional procedures
Frequency
MSK US 1-20 MHz
lower frequency = less detail, but can see deeper
Acoustic impedance
resistance to sound waves
-muscle has less acoustic impedance. Bone has a lot of acoustic impedance (bright)
Echogenicity
Hyperechoic- more reflection (brighter)
Hypoechoic- less reflection (darker)
Doopler
detects flow - vascularity
long and short axis
long axis- parallel
short axis- perpendicular
Disadvantages of MSK US?
Limited field of view limited penetration incomplete evaluation of bone and intra-articular structures -lack of competency and oversight -operator dependent
