skeletal pathology Flashcards
Avulsion fracture
small fragments torn from bony prominence
result of indirectly applied torsion within attached ligaments and tendons
Bennett’s fracture (bennett = thumB)
fracture of the base of the 1st metacarpal CMC joint
Intra-articular fracture
Bimalleolar (the answer is in the name) fracture
Potts fracture
both malleoli are broken with dislocation of the joint
one side is transverse and the other is oblique
another name for potts fracture
bimalleolar
blow- out fracture
A direct blow to the front of the orbit. causes rapid increase in intraorbital pressure.
what is the weakest part of the orbit?
orbital floor above the maxillary sinuses
what is the preferred view to x-ray the orbits for a blowout fracture?
modified waters method
what sinus do the muscles and fat of the orbit leak into in a blow out fracture? how does the sinus appear in imaging?
maxillary sinus. opacified sinus caused by hemorrhage and mucosal edema
what does a presence of air within orbit (orbital emphysema) indicate?
there is a communication with a paranasal sinus.
boxers fracture
transverse fracture of the neck of the fifth metacarpal with volar (palmer) angulation of the distal fragment.
usually caused by blow struck with the fist
closed/simple fracture
the skin isnt broken, single bone
colle’s fracture
transverse fracture through the distal radius with dorsal (posterior) angulation and often overriding of the distal fracture
what fracture usually happens on an outstretched hand?
Colles
what is the most common fracture of the wrist?
Colles
comminuted fracture
fracture with more than 2 pieces
complete fracture
discontinuity between 2 or more fragments
compound fracture
open fracture. when the skin is disrupted
contrecoup fracture
at site opposite to point of impact
MC locations for contrecoup fractures?
cranium and mandible
depressed fracture. where doe sit occur? what is it?
in skull or tibia.
skull: small object with great force can produce a comminuted fracture with portions of the fracture fragments driven inward
knee: hard lateral femoral condyle may impact on the relatively soft lateral tibial plateau with sufficient force to push the cortical surface of the tibia into the underlying cancellous bone
displaced fracture
separation of bone fragments
greenstick fracture? what is it? who usually gets it?
usually in infants
incomplete, cortex intact
hangmans fracture
result of acute hyperextension of the head on the neck.
appears as fracture of the arch of C2 anterior to the inferior facet and is usually associated with anterior subluxation of C2 on C3
what fracture results from acute hyperextension of the head on the neck?
hangmans fracture
incomplete fracture
the bone didn’t break all the way through, its still intact somewhat
intertrochanteric fracture
fracture bw the trochanters
linear fracture
parallel to long axis of bone (fissured fracture)
what is a fissured fracture?
linear fracture. parallel to long axis of bone
longitudinal fracture
follows long axis but it isnt parallel
March fracture
stress fracture. occurs in soldiers when they train.
MC sites for march fracture
shafts of the second and third metatarsals, calcaneus, proximal and distal shafts of the tibia and fibula, shaft and neck of femur, ischial and pubic rami
monteggia fracture
isolated fracture of the shaft of the ulna associated with anterior dislocation of the radius at the elbow
what is the fracture called when the ulna is broken, so the radius gets anteriorly displaced
Monteggia
salter-harris fracture
involves epiphyseal plate, common in children
Smith’s fracture
opposite of colles fracture. wrist flexion distal radius. hand bends down. avulsion of ulnar styloid
what is the opposite of a smiths fracture?
colles
difference between a smiths and a colles fracture
smiths: hand bends with FLEXION. causes avulsion fracture of the ulnar styloid
colles: hand bends backward. causes transverse fracture of the distal radius. pieces go posterior.
trimalleolar fracture
lateral and medial and posterior tibia. fracture and dislocation
supracondylar fracture
superior to the humeral condyles :O
where does ankylosing spondylitis begin
in the Si joints. narrowing joints spaces and sclerosis. leads to complete fibrous and bony ankylosis.
progression of ankylosing spondylitis
SI joints and moves up to the lumbar spine upward
another name for ankylosing spondylitis?
bamboo spine
aseptic necrosis
cystic and sclerotic degeneration due to injury, not infection
is aseptic necrosis due to infection?
nope. due to injury.
what is hip dysplasia
incomplete acetabulum formation caused by physiological and mechanical factors. hip clicks and comes out of the socket.
what views are done for a hip dysplasia?
AP pelvis and bilateral frog leg (cleaves)
how does a hip dysplasia appear on a cleaves view?
dislocated superiorly and posteriorly
what is gout?
disorder in the metabolism of PURINE
increase in the blood level of uric acid leads to the deposition of uric acid crystals in joints, cartilage, and kidney
what causes the overproduction of uric acid?
inherited enzyme defects
what is the difference between primary and secondary gout?
primary: overproduction of uric acid bc of enzyme defect
secondary: hyperuricemia caused by overproduction of uric acid, in turn may be caused by increased turnover of nucleic acids from things like meds of cancer. or decrease of excretion of uric acid bc of kidney failure.
where does gout usually appear first?
initially attacks the first MTP joint
appearance of gout on xray?
joint effusion and periarticular swelling. small sharply marginated punched out defects at the joint margins of the small bones of the hand and feet.
the margins have appearance of cyst like lesions with thin sclerotic margins and characteristic overhanging edges “rat bite erosions”
multiple myeloma
bone marrow malignancy.
widespread malignancy of plasma cells that may be associated with bone destruction, bone marrow failure, hypercalcemia, renal failure, and infections.
how does multiple myeloma look on image?
multiple punched out osteolytic lesions scattered throughout the skeletal system
where is multiple myeloma best seen?
on a lateral skull image
what is osteogenesis imperfecta?
“brittle bones”
inherited disorder of connective tissue. multiple fractures and unusual blue color of the normally white sclera of the eye.
image appearance of osteogenesis imperfecta?
repeated fractures caused by severe osteoporosis. thin defective cortices. Bizzare deformities bc of callus formation. multiple wormian bones in the skull
is osteogenesis imperfecta a destructive or additive disorder?
it is destructive. might need to lower kVp to compensate for the loss of bony quality.
what disorder might be confused with child abuse?
osteogenesis imperfecta
what is osteoarthritis?
loss of joint cartilage and reactive new bone formation. affects weight-bearing joints. (spine, hip, knee, ankle, IP joints of fingers)
radiographic findings of OA
early: narrowing of joint spaces caused by thinning articular cartilage. development of bony spurs.
articular ends of bones become dense
how is bacterial osteomyelitis contracted?
- IV drug abuse (gram negative organisms are found).
- in children: infectious gram positive organisms.
symptoms of acute osteomyelitis
fever and localized warmth, swelling and tenderness
how do diabetic patients and patients with vascular insufficiency get osteomyelitis?
soft tissue infection may spread from skin abscess or decubitus ulcer, usually in the foot, to cause cellulitis and eventually osteomyelitis in adjacent bones.
image appearance of osteomyelitis on x ray?
early: localized deep soft tissue swelling adjacent to the metaphysis. subtle areas of of metaphyseal lucency reflecting resorption of necrotic bone.
later: bone destruction becomes prominent and produces ragged, moth eaten appearance.
what is involcrum?
when large amount of new bone surrounds cortex in thic irregular bony sleeve
what is a sequestra?
dead bone
what is osteoporosis?
deficiency of bone matrix. mass of bone per unit volume is decreased.
what is the word for old bone being removed?
osteoclastic process
what is the word for new bone being built?
osteoblastic process.
what causes osteoporosis (The osteo activity)?
accelerated resorption of bone or decreased bone formation
- Decreased bone formation+ increase in bone resorption = loss of bone density
how to adjust technical factors when xraying a patient with osteoporosis?
must use lowest possible kVp. provides extremely short scale of contrast necessary to visualize the demineralized osteoporotic bones.
image appearance of osteoporosis?
- cortical thinning with irregularity and resorption of endosteal (inner) surfaces.
what are the major causes of osteoporosis?
aging and postmenopausal hormonal changes
where are the findings of osteoporosis most evident?
- spine and pelvis
where does osteosarcoma generally occur?
in the end of a long bone in the metaphysis especially about the knee.
what does the osteosarcoma tumor consist of?
osteoblasts which produce osteoid and spicules of calcified bone.
what is the radiographic appearance of osteosaracoma?
- destructive and sclerotic lesion associated with soft tissue mass, irregular periosteal reaction, and reactive new bone formation.
- sunburst pattern
- codmans triangle: elevation of the periosteum at the periphery of a lesion, with susequent new bone formation
what is codmans triangle?
elevation of the periosteum at the periphery of a lesion, with susequent new bone formation
what is pagets? (osteitis deformans)
- chronic metabolic disease of skeleton.
- destruction of bone followed by reparative process. result in weakened, deformed, and thickened bony structures that tend to fracture easily.
what is the common age for development of osteosarcoma?
-10 to 25 with increased chance in patients with bone disorder like paget’s osteitis deformans)
Does pagets affect women twice as much as men?
- no the opposite.
image appearance of pagets?
- area of demarcated radiolucency = destructive phase
- irregular islands of sclerosis and cortical thickening = mottled and cotton- wool appearance –> reparative process
what would a bone scan show for pagets?
- cold spots = initial destructive phase
- hot spots = reparative process
what is the most common initial spot for pagets?
the pelvis
what is a complication of pagets?
osteosarcoma
rheumatoid arthritis
chronic systemic disease of unknown cause. appears as nonsuppurative (noninfectious) inflammatory arthritis of small joints of the hands and feet.
how much more often are women affected by RA than men?
- 3X more
what is the average age onset of RA?
40
RA manifestation?
- starts as an inflammation of the synovial membrane (synovitis) that lines the joints
- excessive exudate causes proliferation of the synovium
- the mass of thickened granulation tissue causes erosion of the articular cartilage
- ## develops ankylosis
image appearance of RA?
- early: fusiform periarticular soft tissue swelling caused by joint effusion
- leads to osteoporosis.
- destruction of joint space and leads to ankylosing spondylitis
what is spina bifida?
- posterior defect of the spinal canal resulting from failure of the posterior elements to fuse properly
what is the mild form of spina bifida?
occulta- splitting of the bony neural canal at the L5 or S1 level.
can large defects in spina bifida of the lumbar and cervical spine cause herniation of the meninges? (meningocele)
yes sir
image appearance of spina bifida?
large bony defects, absence of laminae, increased interpedicular distance
spondylolisthesis
displacement of pars interarticularis
spondylolysis
cleft in the pars interarticularis- not displaced.
which part of scotty dog demos the pars interarticularis?
the neck- demonstrated on lumbar spine oblique
spondylosis
type of arthritis spurred by wear and tear to the spine. It happens when discs and joints degenerate, when bone spurs grow on the vertebrae, or both. These changes can impair the spine’s movement and affect the nerves and other functions.
what is a hill sachs defect? what views best demonstrate it?
it is a depression in the posterolateral humeral head into the anteroinferior glenoid rim. the shoulder gets dislocated anteriorly.
demonstrated on a grashey method shoulder AP oblique, exaggerated external rotation or inferosuperior axial.
