Orthopaedic radiology

Question 1

RADIOLOGICAL EXAMINATION

Answer 1

• Description of a long bone from an X-Ray
 Name, date
 View, bone, side, area, type, deformity / displacement

Question 2

SYSTEMATIC ASSESSMENT

Answer 2

•Alignment and Adequate=
Adequacy 
Apleys rule of 2’s
 2 views
 2 joints
 2 sides
 2 times

Adequate penetration

Alignment=Anatomic alignment between bones

•Bone density and dimension 
Is the structure normal?
Is the alignment correct?
Radiolucent lines?
Bone sclerosis?
Is the bone shorter or longer 
than normal?

•Cartilage= Joint spaces
Articular surfaces normal?
Widening of joint surfaces?
If deformed are they 
congruous?
Dislocation or subluxation?
Joint space?
Subchondral bonesclerotic, cystic or 
porotic?
Periarticular erosion or 
osteophytes?

•Soft tissue=
 Degree of X-ray penetration
• Look for: swelling, calcifications, opacities, gas, foreign body (where does it appear to be?).
• Don’t substitute imaging for Subjective and Objective examination
• Correlate X-ray to assessment findings
• NB late presenting #’s

Question 3

What is displacements and the types?

Answer 3

Displacement
•When there is no alignment = DISPLACEMENT
Requires at least 2 views

types:
1. Shortening- overlap of fragments
2. Impaction- one fragment is driven into another
fragment
3. Shift (translation)- fragments may shift sideways,
backwards, forward
4. Tilt (angulation)- malalignment, may lead to limb
deformity
5. Twist (rotation)- rotational deformity

Question 4

TYPES OF FRACTURE FRAGMENT ALIGNMENTS

Answer 4

Displacement
Angulation
Rotation
Shortening
Distraction

Question 5

Acceptable displacement: long bone shaft #

Answer 5

• Shift - 50% (of the diameter of the shaft)
• Shortening -10mm
• Twist -0°
• Tilt -10°
• Impaction -10mm

Question 6

Acceptable displacement: articular surface fracture’s

Answer 6

Large joint Small joint
Gap Up to 5mm 2mm
Step Up to 2mm 1mm
Impaction Up to 2mm 1mm

Question 7

Bone density and dimension

Answer 7

Bone texture
Periosteum
Cortex (outer) 
Medulla (inner)
Bone density

Question 8

Bone lesions

Answer 8

• Location
• Site
• Extent
• Contents
• Margin
• Periosteal reaction

Question 9

Management approach

Answer 9

• Is the # displaced?
• If so, is the displacement acceptable?
• If not, is reduction necessary?
• If so, should open or closed reduction be 
used?
• How should it be immobilized?

Question 10

Other modalities:

Answer 10

Other modalities: 
CT Scan
• Shows bone and soft 
tissue in cross section
• Useful in articular & 
spinal pathology
• Useful to show fracture 
pattern and spread of 
tumours into tissue
• 3-D
• High level of radiation

MRI
• Soft tissue imaging
neural tissue, 
ligaments and 
tumours.
bone bruising or 
edema
aseptic bone necrosis
(these will not be seen 
on x-ray)
• No ionizing radiation

• US: For soft tissues around joints
• Bone Scan
• Fluoroscopy

Question 11

types of fractures

Answer 11

1. Simple spiral fracture
2. Simple oblique fracture
3. Simple transverse fracture
4. Wedge fracture
5. Multifragmentary (comminuted) fracture

Also the fracture displacement is described.
• Shortening
• Angulation
• Rotation