Exam 6 Radiology/fractures/ultrasound Flashcards
What is radiopaque?
relative impenetrability to x-rays
What is radiolucent
relative penetrability to X-rays
What should be done prior to ordering an x-ray?
an excellent history and physical
What is the metaphysis? Diaphysis?
Metaphysis is the end of a bone proximal to the growth plate, diaphysis is the shaft of a bone
What is an epiphysis? Epiphyseal plate?
The part of the bone distal to the growth plate; its the growth plate
What is an apophysis? Apophyseal plate?
A growth plate that has a tendon attached to it (tibial tuberosity); A growth plate under an apophysis
What should always be done with fractures?
Obtain at least 2 views of the involved bone, ideally in perpendicular planes; look for indirect signs of fracture
What are indirect signs of a fracture?
soft tissue swelling, obliteration or displacement of fat stripes, periosteal and endosteal reaction/thickening, buckling of cortex, double cortical line
What is a supracondylar fracture; intraarticular?
Supra is just above, intraarticular in a break of half of the articular surface
What is a comminuted fracture?
a break off of the bone with a complete transverse fracture
What is the differential diagnosis of arthridities?
Osteoarthritis, Inflammatory arthritis, Seronegative spondyloarthropathies, crystal depositiona arthropathy, metabolic/endocrine, infectious
What is an important clinical presentation that can tell you which arthritis a patient has?
the distribution of the involved joints
What does osteoarthritis look like in an x-ray?
marginal osteophytes, cortical irregularity, subchondral sclerosis, subchondral cysts, joint space narrowing
What does an xray of rheumatoid arthritis look like?
Periarticular osteoporosis, joint effusion, joint space narrowing, articular erosions/destruction, synovial cysts, deformities
What is the composition of bone?
Organic-30% (cells, matrix/collagen), Mineral-70%(hydroxyapatitie, MG, Na, K, Fl, Cl)
What is intramembranous ossification?
Mesenchymal progenitor cells differentiate into osteoblasts which then directly form bone
What is endochondral ossification?
Mesenchymal progenitor cells differentiate into chondrocytes, initially forming a cartilage intermediate that is replaced as bone is regenerated
Where is most cortical/compact bone?
Long bones
Where are trabecular/cancellous bone
mostly flat bones
What is the structure of cortical bone?
Haversian systems, nutrient arteries, periosteum, endosteium
What is the structure of trabecular bone?
mostly a lattice system instead of a Haversian system
What are the two types of bone?
Woven and lamellar
What is the difference between woven and lamellar?
Woven is laid down pretty quickly, but is transient and replaced by lamellar bone for long term structure
What happens in the initial fracture?
Trauma > injury to cells, blood vessels, bone and soft tissue > hematomas form and damage to blood vessels leads to osteocyte death and necrotic tissue
What happens in the inflammatory phase of a fracture?
Release of cytokines leads to vasodilation (edema) and migration of inflammatory cells (initially neutrophils, then macrophages and lymphocytes)
What does migration of inflammatory cells to the site of the fracture lead to?
release of cytokines to increase angiogenesis leading to increases in fibroblasts and osteoblasts for new matrix, and osteoclasts to resorb necrotic tissue
T/F: Osteocytes are involved in fracture repair?
FALSE- they aren’t!!!
What decreases pain of a fracture initially?
the formation of a soft callus to lessen movement
What do pluripotent mesenchymal cells differentiate into?
osteoblasts, chondrocytes, fibroblasts
What do monocytes differentiate into?
osteoclasts
What does fracture healing depend on?
recruitment, proliferation, accumulation and differentiation of pluripotent mesenchymal cells at the site of the fracture
What does the transition from a soft callus to a hard callus look like?
Intramembranous bone formation at the periphery (proximal and distal to the injury site, endochondral bone formation overlying the site
What is a clinical union?
when the fracture site becomes stable and pain free
What is a radiographic union?
plain radiographs show bone trabeculae or cortical bone crossing the fracture site
What happens in the remodeling phase of fracture healing? How long does it last?
Replacement of woven bone with lamellar bone, resorption of unneeded callus; May continue for years
What are some variables that influence fracture healing?
Injury (soft tissue damage, bone comminution and displacement, location of bone injury), Patient’s age, Treatment variables (fracture stabilization)
T/F: an internal plate repair affects healing process? How?
True, fracture skips over woven bone formation and directly moves to lamellar bone, leading to not as good of a fracture healing
T/F: a Salter-Harris class III fracture is something to worry about in children? Why?
True; affects the proliferating zone of cells at the distal half of the growth plate?
Where is the proliferative, hypertrophic and metaphysis section of a growth plate?
Proliferative is at the distal part, hypertrophic is where cells continue to mature until they are added onto the metaphysis. DON’T HURT THE PROLIFERATIVE ZONE
