Lesson 13 - Msk Radiology - Revised

Front 1

Columns of the vertebrae

Back 1

- 3 total
- *Anterior: ant. longitudinal ligament and ant. 2/3 of vertebral body
- *Middle: posterior 1/3 of vertebral body and post. longitudinal ligament (PLL)
- *Posterior: everything past PLL

Front 2

Mnemonic for cervical spine

Back 2

AABCDS
Adequate Film
Alignment
Bony Landmarks
Cartilaginous Space
Disc Space
Soft tissues

Front 3

Requirements for adequate cervical spine film

Back 3

- Should include all 7 vertebrae and C7-T1 junction. (C7 MUST be visualized on the lateral view)
- It should also have correct density and show the soft tissue and bony structures well.

Front 4

Requirements for alignment of cervical spine film

Back 4

4 parallel lines
1. *Ant. vertebral line: ant margin of vertebral bodies
2. *Post vertebral line: post margin of vertebral bodies
3. *Spinolaminar line: post margin of spinal canal
4. *Post spinous line: tips of spinous processes

- Lines should follow a slightly lordotic curve
- Smooth, no step-offs
- Any malalignment should be considered evidence of ligamentous injury or occult fx - C spine must be immobilized until dx made

Front 5

Evaluating alignment on A-P view of C spine

Back 5

- *Use edges of vertebral bodies and articular pillars
- *Height of c-spine vertebral bodies should be approx. equal on AP view, and *equal @ all levels
- *Spinous process should be midline and in good alignment.

Front 6

On C-spine xray, vertebral bodies should be ___ in shape and roughly equal in size.
Exceptions

Back 6

- *Rectangular
- C1, 2 not rectangular
- Height of C4 and C5 may be slightly less than C3 and C6

Front 7

*Pedicles on c-spine xray

Back 7

- Both R and L should superimpose on true lateral views.
- If fx is suspected, get oblique views or CT.

Front 8

*Lamina on c-spine xray

Back 8

- Posterior elements are seen poorly on the lateral film.
- Best demostrated by CT.

Front 9

Predental space - what is it and AKA...
Normal measurements in adults and children

Back 9

- Cartilaginous space b/w dens and anterior arch of C1
- AKA as ADI: Atlanto-dens Interval
- *Adults = 3mm or less
- *Children = 5mm or less

Front 10

Causes of increased predental space
Next step?

Back 10

- Fx, then get a CT
- Ligamentous injury, then get an MRI

Front 11

Odontoid view
- Should see
- Alignment

Back 11

- *Entire odontoid and lateral borders of C1-C2
- *Occipital condyles should line up with the lateral masses and superior articular facet of C1
- distance from dens to lateral masses of C1 should be equal bilaterally
- Tips of lateral mass of C1 should line up with the lateral margins of the superior articular facet of C2
- *Odontoid should have uninterrupted cortical margins blending w/ body of C2

Front 12

Nasopharyngeal space - location (on lateral xray) and normal measurement (adult)

Back 12

- Anterior to C1
- 10 mm (adult)

Front 13

Retropharyngeal space- location (on lateral xray) and normal measurement
Decreased in ...

Back 13

- Anterior to C2-C4
– 6mm
- Epiglotitis

Front 14

Retrotracheal space

Back 14

- Anterior to C5-C7
- 14 mm in kids
- 22mm in adults

Front 15

*Jefferson cervical fx
MOI
MC area fx'd

Back 15

- Fx of C1 (atlas)
- Typical MOI: *axial compression w/ or w/o ext force*
- MC is posterior arch, result of hyperextension injury (diving into shallow water)

Front 16

Presumptive evidence for _______ ligament disruption can be seen on a lateral xray if ADI > 3mm

Back 16

- Transverse ligament

Front 17

Hangman's cervical fx
MOI
What can result?

Back 17

- Fx of C2 (axis) pars interarticularis
- MOI: *hyperextension with or without axial loading*, (MVA)
- Anterior movement (spondylolisthesis) of C2 results and causes prevertebral soft-tissue swelling

Front 18

Clavicle fracture MOI

Back 18

Typically due to a fall on the outstretched arm or fall onto the lateral shoulder.

Front 19

Acromioclavicular dislocation MOI

Back 19

Typically due to direct downward blow to the tip of the shoulder. (*football*, wrestling, hockey)

Front 20

Shoulder/Humerus fx locations

Back 20

1. Proximal
2. Midshaft
3. Distal – epicondyle (medial/lateral)

Front 21

Shoulder/humerus dislocation MOI and location

Back 21

- External rotation abduction force on humerus, or posterior to postero-lateral blow.
- Typically anterior and inferior (MC is anterior)

Front 22

Xray of osteoarthritic shoulder - views
What changes can you see?

Back 22

3 view X-ray: AP, Axillary, and Lateral
- Loss of joint space and bone spurs

Front 23

Radial head fx
MOI
Pain during what mvmts - why?

Back 23

- Typically d/t fall w/ outstretched hand
- Pain and difficulty supinating/pronating (bc of ligament damage)

Front 24

Colle's fx - description, MOI, tenderness where?

Back 24

- Distal radius fx w/ dorsal displacement of the hand/wrist
- Fall on outstretched arm
- very tender on distal radius

Front 25

Ulnar fracture - MOI

Back 25

Mechanism is direct impact, as with fall

Front 26

Dislocation of the elbow - description, MOI, presentation

Back 26

- Usually caused by fall on the outstretched arm
-MC - posterior displacement of the olecranon to the humerus
- Arm is shortened and held flexed

Front 27

Pelvic fx- MOI and complications

Back 27

- Result of direct trauma
- Can cause nerve, blood vessel, bladder, or bowel complications

Front 28

Hip/femur fx - MC over what age? MOI

Back 28

- MC > 50yo
- Fall

Front 29

Femoral neck fx presentation

Back 29

The involved extremity is externally rotated and slightly shortened

Front 30

Femoral trochanteric fxs - 2 types, presentation, age compared to femoral neck fx

Back 30

- Intertrochanteric - the involved extremity may be internally rotated and slightly shortened
More common at later age then femoral neck
- Greater trochanteric

Front 31

Hip/femur dislocations - MC which direction, presentation

Back 31

- MC is posterior (and superior)
- Typically shortening, adduction, and internal rotation of the extremity is seen

Front 32

Slipped capital femoral epiphysis (SCFE)- description, presentation

Back 32

- Adolescent disorder - fx of growth plate
- M>F
- Overweight
- Causes painful limp and limited hip internal rotation and ABDuction
- Change in ROM usually diagnositc

Front 33

Most bone tumors are...

Back 33

Osteolytic

Front 34

Most important determinates in the analysis of a potential bone tumor are...

Back 34

- Morphology of the bone lesion on a plain radiograph (Well-defined osteolytic? ill-defined osteolytic? Sclerotic?)
- Age of pt
- Plain xray is the most useful examination for differentiating these lesions
- CT and MRI are only helpful in selected cases.

Front 35

Periosteal rxn - def, types

Back 35

- Non-specific rxn that occurs when periosteum is irritated by a malignant tumor, benign tumor, infection, or trauma
- Types: benign and aggressive

Front 36

Benign periosteal rxn seen in...
Appearance

Back 36

- Benign lesions such as bone tumors and following trauma
- AKA Solid periosteal rxn
- Rxn appears as a *thick, wavy and uniform callus resulting from chronic irritation*
- In the case of benign, slow growing lesions, the periosteum has time to lay down thick new bone and remodel it into a more normal-appearing cortex

Front 37

Aggressive periosteal rxn seen in

Back 37

- Malignant tumors
- Also can be seen in benign lesions with an aggressive behavior (ie: infections and eosinophilic granuloma)

Front 38

*Small zone of transition on bone lesions results in ...
Sign of ...

Back 38

- Results in a sharp, well-defined border
- Is a sign of slow growth.

Front 39

A sclerotic border especially indicates ...

Back 39

poor biological activity

Front 40

Regarding bone lesions - An ill-defined border w/ a *wide zone of transition* is a sign of...
It is a feature of ...

Back 40

- Aggressive growth
- Malignant bone tumors

Front 41

Two tumor-like bone lesions that may mimic a malignancy and must be included in the DDx when the lesion has a wide zone of transition

Back 41

- Infections
- Eosinohpilic granuloma

Front 42

Lamellated periosteal rxn AKA

Back 42

- "Onion-skinning"

Front 43

Types of aggressive periosteal rxns

Back 43

- Lamellated or multilayered
- Spiculated/ interrupted/ "Hair on end"/ "Sunburst"
- Codman's triangle

Front 44

Codman's triangle

Back 44

Refers to elevation of the periosteum away from the cortex, forming an angle where the elevated periosteum and bone come together
- Tumor breaks cortex layer
- In aggressive periostitis, the periosteum doesn't have time to consolidate

Front 45

Osteoid osteoma - def, MC location, xray appearance

Back 45

- Unknown etiology
-Benign bone tumor composed of osteoid and woven bone
- Usually < 1.5cm in diameter
- Can occur in any bone, MC in appendicular skeleton
- Focal bone pain @ site of tumor, worse @ night and increases with activity
- Pain relieved by aspirin
- Xray typically shows round lucency containing a dense SCLEROTIC central nidus

Front 46

Osteochondroma - def, age, and appearance

Back 46

- Benign bone tumor that develops during childhood or adolescence.
- Abn growth that forms on the surface of a bone near the growth plate
- Outgrowth of the growth plate and is made up of both bone and cartilage

Front 47

Enchondroma - def, MC age, appearance on xray

Back 47

- Benign bone tumor composed of intramedullary catilaginous cysts
- MC in small bones of hands and feet
- Grow in childhood, then stop growing but remain present throughout adulthood
- Often found in pts 10-20yo
- Xray: small < 5cm, lobe-shaped or oval, well-defined margins. In larger lesions, the lucent defect has endosteal scalloping (erosion) and cortex is expanded and thinned. Calcifications throughout lesion range from punctate to rings - "Bubbles w/in bones"

Front 48

Aneurysmal bone cyst (ABC) - def, age, appearance

Back 48

- Benign bone tumor
- Usually 20s and 30s
- Upper surface of bone as well as epiphysis or metaphysis
- Xray shows expansile lesion w/ internal septae of longitudinal striations, expansile nature can make bone appear much larger than normal
- Can be well-defined or appear sclerotic if healed
- If highly expansile and @ end of bone - "Finger in a ballon"

Front 49

Osteosarcoma - def, age, location, appearance

Back 49

- Malignant bone tumor
- Peak age: 18 or 20yo, although all ages can be affected
- M> F
- Typical presentation - pain and mass near joint (MC knee)
- MC in metaphysis of long bones, 50% seen about knee joint
- Appears as mixed sclerotic and lytic lesions causing periosteal rxn - "Sunburst rxn"

Front 50

Chondrosarcoma - def, age, location, appearance

Back 50

- Malignant, bone tumor that produces cartilaginous matrix
- Slower growing than osteosarcomas
- MC location = metaphysis of long bones
- MC in > 60 yo
- Presents w/ pain and swelling in bone
- Fusiform, lucent defect w/ scalloping of inner cortex and periosteal rxn
- Extension into soft tissue may be present
- Usually ill-defined

Front 51

Ewing's sarcoma

Back 51

- Malig. bone tumor
- MC in pelvis, femur, tibia, and humerus (usually long bones)
- M> F
- MC presents in childhood
- Lamellated or "onion-skin" rxn. - caused by splitting and thickening of the cortex by tumor cells, followed by "moth-eaten" or mottled appearance and ext into soft tissue
- Lesion is usually ill-defined lytic and central
- Endosteal scalloping is often present