DI 2 Midterm Flashcards
What is the relation between occipitalization and basilar invagination/impression?
Occipitalization: Nonsegmentation of occiput from C1.
Occipitalization is one of the etimologies of basilar invagination, which is Odontoid encroachment into foramen magnum
compare with Arnold-Chiari malformation: part of brainstem is thru foramen magnum
Where do you find a posterior ponticle?
between occiput and C1
ossification of the vertebral membrane thru which the vertebral artery and 1st cervical nerve pass
What is the significance of George’s line?
Line drawn along posterior edge of vertebral bodies to estimate alignment, should be smooth curve; if not, indicates spondylolithesis or bone loss/gain/malformation/etc
Why is an os odontoideum clinically significant?
possibility of severing spinal cord -> set up appt with neurosurgeon
What are the radiographic differences between congenital block vertebra and an acquired fusion of the spine?
congenital block vertebra:, Decreased AP diameter, rudimentary disc, apophyseal joint fusion, possible malformation or fusion of SPs. Wasp waisted appearance (of discs, not of Pt)
acquired fusion: normal vertebral bodies, radiopacity between bodies d/t sclerosis or bone chips
What is the significance of the spinolaminar junction and spina bifida occulta in the lateral view?
It’s not visible on the lateral view, since the two lamina don’t come together. In normal SPs on a lateral view, one can see the radiopaque line indicating thickness of the two lamina’s connection, whereas in SBO lamina don’t have that additional thickness and appear relatively radiopaque.
Why is it common to see disc space narrowing adjacent to a limbus vertebra and/or Schmorl’s node?
because the disc isn’t in the disc space, it’s in the body space
How can you tell whether a rib at the cervicothoracic junction is a cervical rib or first rib?
cervical TPs point up, thorasic TPs point out, so check the TP that the rib is attached to
What is a transitional lumbosacral vertebra?
a vertebra that resembles both an idealized lumbar vertebra and the sacrum, would be L5 probably
Name a dysplasia that may present with tall stature and hypermobile joints?
Marfans
What complications may be associated with marfans?
- kyphoscoliosis;
- aortic dissection aneurism;
- joint dislocation;
- retinal dislocation
- What is the most common cause of dwarfism
2. What neurologic condition may these individuals have that affects the legs?
- achrondoplasia, hereditory autosomal dominant trait
2 In the infant, the small foramen magnum and hydrocephalus can lead to cord compression. In the adult, congenital spinal stenosis often leads to paraplegia.
Fragile osteopenic bones are associated with which dysplasia?
Osteogenesis Imperfecta
compare new and old fractures
new: not much. edema, fat displacement (elbow), air (open/compound fracture), if large enough, a radio-lucenct (if gapping) or radiopaque (if compressed) area
old: callus where new bone has grown, either as cortex or as bridging bone
What are the possible long bone fracture orientations?
transverse, oblique, longitudinal
“long bones are TOL”
What are the types of incomplete fractures of pediatric long bones and how do they differ?
Torus, Green stick, Bowing
“ TEE-Bow”
“Incomplete pass”
Which is the most common type of Salter Harris fracture?
type II: growth plate and metyphasis
What is the difference between a malunion and a nonunion fracture?
malunion is where the bone heals unaligned, in a different form than it had originally
nonunion is where each new fragment of the bone heals itself rather than joining back into the original bone
What significant finding is demonstrated in the APOM view with a Jefferson’s fracture?
The lateral aspect of C1 should not project beyond the lateral margins of C2 by a combined measurement of 7 mm
i.e. C1 lateral aspects slide laterally d/t fractures bilaterally ant and post
What is traumatic spondylolisthesis and what cervical level does it usually occur at?
Hangman’s fracture, C2
What are the key radiographic differences between an ununited secondary ossification center of the spinous process at the cervicothoracic junction and a clay shoveler’s fracture?
nonunion of growth center will be smooth, clay shoveler’s frxr will be jagged-edged and caudally displaced
What is the most common fracture of the spine and how do you differentiate new from old? (hint: it occurs usually at T12-L2)
compression fracture
Hemorrhage, hematoma, step defect, and zone of impaction indicate fracture less then 2 months old
Old fractures often show contiguous disc degeneration (if L1-2 frxr, T12 and L2 djd)
List and describe the unstable fractures of the pelvis.
unstable: Trauma that results in the possibility of organ or vascular damage
Malgaigne: Unilateral sacroiliac fracture/dislocation and ipsilateral superior pubic and ischiopubic rami fractures (3 points, psi)
Bucket-handle: Unilateral sacroiliac fracture/dislocation and contralateral superior pubic and ischiopubic rami
What is the most common type of acetabular fracture?
Posterior rim frxr, where femur is driven into acetabulum (a.k.a. dashboard fracture)
What is the most common hip (proximal femur fracture) and what age do these often happen in?
Subcapital: Junction of head and neck (MC – often missed), elderly predisposed by bone-wasting dx
Name and describe the proximal femur fracture that happens only in adolescents.
Slipped Capital Femoral Epiphysis, obese 10-15y.o., pain referred to knee
Which direction does the patella usually dislocate?
superolaterally (stronger muscle)
What is a Jones’ fracture and what bone does it occur in?
a.k.a. dancer’s fracture, proximal 5th metatarsal (transverse, as oblique might be growth plate)
Name an associated injury that must be evaluated for when a patient presents with a calcaneal compression fracture.
thoracolumbar spinal vertebra fracture (burst or compression
What are the different types/grades of acromioclavicular joint sprain?
1: acromioclavicular & corococlavicular ligaments stretched
2: acromioclavicular ligament ruptured/stretched, corococlavicular ligament stretched
3: both ligaments ruptured
in all three, SCM pulls clavicle superiorly
What is the radiographic difference in anterior vs. posterior glenohumeral dislocations? Which is most common?
anterior is far more common
• dislocates medio-inferiorly
• may see Hill-Sachs/Hatchet sign or Bankart lesions (see below) from frequent dislocation
posterior is far less common
• dislocates superio-laterally and overlaps w/ glenoid fossa in Grassey view
• has to do with severe spasm or muscular strain (convulsions, electric shock) or direct trauma forcing backwards
What are Hill-Sachs/Hatchet and Bankart lesions and what are they associated with?
anterior glenohumeral dislocation, d/t frequent banging of humerus on inferior lip of glenoid
Hill-Sachs/Hatchet is on humeral head
Bankart is on glenoid
Which part of the clavicle most commonly fractures?
middle 1/3 (80%), then lateral 1/3 (15%) then medial 1/3 (5%)
What is the significance of the elbow fat pad signs (anterior and posterior)?
bleeding or edema into area has displaced the fat pad from
What structures are involved in the most common fractures of the elbow in children and in adults?
children: supracondylar humerus
adults: head or neck of radius
What are the most common wrist fractures seen in each of the following age groups: children, young adults, elderly?
children: Distal Radius Torus Fracture (6-10y.o.)
young adults: scaphoid fracture
elderly: Colles’ fracture, especially women
Describe the difference between Colles’ and Smith’s fractures at the wrist.
Colles’: Distal radius fractured about 20-35 mm proximal to the joint surface, distal fragment is angulated posteriorly, sometimes with ulnar styloid, from FOOSH injury
Smith’s: Distal radius fracture with distal fragment angulated anteriorly, from wrist hyperflexion
Discuss the vascular supply of the scaphoid and its effect in avascular necrosis and healing of this structure after fracture
First: 70% occur at scaphoid waist, 20% at proximal pole, and 10% at distal pole
blood supply arteries are at waist and distal pole area, so proximal is harder/slower to heal
non-union fractures separating proximal pole from blood supply also cause AVN
What is the most common carpal bone to dislocate and in what direction?
lunate, anteriorly
What are barroom and boxer’s fractures of the hand?
- The fracture of metacarpals one would see after a punch:
- jab (boxer -> 2, 3)
- roundhouse ( barroom -> 4, 5)
What is gamekeeper’s thumb?
a.k.a. skier’s or ski-pole thumb:
dislocation/fracture of extreme abduction/extension (you fly foward, your thumb stays behind)
What are the common sites of a stress fracture?
- Metatarsals – aka “march fracture”, “deutchlanders disease”
- Proximal tibia, calcaneus, distal fibula
- hook of the hamate
- distal one third of the clavicle
- dang those SCMs!
- L5 pars interarticularis (most common stress fracture in the spine)
How can stress fractures be detected on plain x-ray?
with great difficulty, if at all. Check after 2 weeks~20 days for callus formation -> radiopacity
What imaging type(s) are most sensitve in detecting stress fractures?
MRI shows edema and subtle density differences
What are the most common types of spondylolisthesis in the lumbar spine?
- 2 main types
- isthmic: pars @ L5 (90%), stress, in active kids
- look for “collar” on “scotty dog”
- L4 on L5
- type 3 - degenerative arthritis, L4 slides fwd on L5
Discuss the differences between spondylolytic spondylolisthesis and degenerative spondylolisthesis.
one is in active adolescents with hyperlordosis/extension, esp girls, and one is in older adults.
Make sure to include the etiology of each and what spinal level are spondylolytic spondylolisthesis and degenerative spondylolisthesismost common at.
spondylolytic spondylolisthesis: L4 slides on L5
degenerative spondylolithesis: L3 slides on L4
What is the Meyerding’s grading system?
- on a lateral lumbar projection:
- The sacral base is divided into 4 equal sections.
- Grade 1 The posterior-inferior corner of L5 is aligned with the first division
- Grade 2 “ “ second division
- Grade 3 “ “ third division
- Grade 4 “ “ fourth division
- Grade 5 is spondyloptosis (L5 anterior to S1)
What is an inverted/reversed Napoleon hat sign?
\on a Lumbar Spine spot film, L5 is so far anterolistheses’ed that it looks like an inverted Napoleon hat (body inferior, TPs laterally from top-down and SPs etc blended w/ L4
