Download Emergency Department Radiography

Radiograph Interpretation of the
Peripheral Skeleton
Author: Adam de Gruchy
Last review March 2013
Rules of 2s
1.
2.
3.
4.
5.
2 views
2 joints: image the joint above and below a long bone
2 sides: compare the other side (in difficult cases only eg children)
2 abnormalities
2 occasions: compare current films with old films if available
(especially chest x-rays)
6. 2 visits: repeat the film after a procedure or period of time
7. 2 opinions: ask a colleague for an opinion
8. 8. 2 records: write down clinical and radiographic findings
9. 9. 2 specialists: also get a formal radiological report
10. 2 examinations: don’t foget other tests such as US, CT, MRI, bone
scan
2 views – Standard Views
•
•
•
•
•
•
•
•
•
•
•
•
•
Finger = AP and lateral
Hand = AP and oblique
Wrist = AP and lateral +/- scaphoid views
Elbow = AP and lateral
Shoulder = AP and Y view
Pelvis = AP only
Hip = AP and oblique/lateral
Knee = AP and lateral
Ankle = AP and lateral +/- AP mortice view
Feet/toes = AP and oblique
Cervical = AP, lateral and peg
Thoracic = AP and lateral
Lumbar = AP and lateral
10 Commandments
1.
2.
3.
4.
Treat the patient not the radiograph
Take a history and examine before requesting a radiograph
Request a radiograph only when necessary
Never look at the radiograph without seeing the patient and never
see the patient without reviewing the radiograph
5. Look at the radiograph, the whole radiograph and the radiograph
as a whole in appropriate settings
6. Re-examine the patient when incongruity exists between the
radiograph and expected findings
7. Remember the rules of 2
8. Take radiographs before and after procedures
9. If a radiograph does not quite look right, ask and listen
10. Ensure you are protected by failsafe mechanisma
ABC Systematic Assessment
• Alignment
• Bones – exclude a fracture by carefully
following the bony contours and checking
bone density and trabecular pattern
• Cartilage and joints – joint space should be
uniform in width
• Soft tissues and foreign bodies
Hand
Hand
• Standard view
– AP
– Oblique
Hand
• Adequacy and Alignment
– 2 views are needed to rule out dislocation
– Oblique or lateral view is needed to detect
Bennett’s and triquetral fractures
Hand
• Bone
– Commonest sites of injury are:
• Finger tip (crush fracture)
• Base of distal phalanx (mallet finger)
• Neck of 5th metacarpal (boxer’s fracture)
• Cartilage and joints
– Look for overlapped joint space indicating
subluxed or dislocated joints
Hand
• Small avulsion injuries at the base of the
phalanx may require further attention, such
as:
– Avulsion at base of the proximal phalanx on the
palmar surface may indicate a volar plate injury
– Avulsion on the lateral or medial aspect would
indicate collateral ligament instability
– Avuslion at the dorsal aspect of the base of the
distal phalanx indicates a mallet finger
Hand
Volar plate injury - avulsion
Hand
• Thumb Injuries
– Skier’s or Gamekeeper’s Thumb
• Ulnar collateral ligament injury at the MCP joint. May
have an associated avulsion injury.
• May require US scan to confirm diagnosis
– Bennett’s Fracture
• Fracture to base of first MC. Unstable as technically
intra-articular and fracture/dislocation
• Note 3 part fracture to the base is called a Rolando
fracture
Hand
Bennett’s Fracture
Rolando Fracture
Wrist
Wrist
• Standard views
– AP
– Lateral
• Additional views
– Scaphoid
– Clenched fist
Wrist
• Age related injuries:
– 4-10 = Torus and greenstick fractures
– 11-16 = Salter-Harris injuries
– 17-40 = scaphoid and triquetral fractures
– 40 to >60 = Colles’/Smith’s fractures
Wrist
Alignment
• AP views:
– Gilula’s arcs should be parallel and 1-2 mm apart in
adults
– Check lunate is square if triangular then ? dislocation,
and check for widening between scaphoid and lunate
– Distal ulna should overlap the radius slightly or almost
touch it. Distal radius should be distal to distal ulnar
styloid with a 5-10° ulnar deviation. Rule of 11s for
radial inclinations.
Wrist
Wrist
Wrist
Wrist
• If the lunotriquetrial ligament is broken then the scaphoid will tip the
lunate in a volar direction (VISI).
• If the scapholunate ligament is disrupted then the triquetrium will tip
the lunate in a dorsal direction (DISI).
• If there is a break in the scaphoid, lunate, triquetrial connection then a
DISI or VISI malalignment can occur which depends on where the break
occurs.
Wrist
Alignment
• Lateral views:
– The radius, lunate, capitate and base of third MC
all should articulate with each other
– The lunate should look like a moon with its
concavity facing distally, filled by the capitate
– Palmar angulation of the radiocarpal joint should
be 10-15°
Wrist
Bone
• AP views:
– Check the overall contour and bony margins of
each bone and then trabecular pattern = linear
lucency, line of sclerosis or a cortical break
– start proximal and work distal
• Lateral views
– Any flake of bone may be avulsion injury
Wrist
Cartilage and Joint
• Check for narrowing or widening of joint space
as can indicate dislocation
Wrist
Fractured radius and scapholunate dissociation
Wrist
Soft tissues
• Displacement of pronator quadratus fat pad
(MRI studies show not reliable in # diagnosis)
• Fat stripe = radiolucency on the radial side of
the scaphoid (not seen < 12 years old)
Wrist
Pronator teres fat pad sign
Elbow
Elbow
• Standard views
– AP
– Lateral
• Additional views
– Radial head-capitellum view
– Oblique/olecranon view
Elbow
Alignment
• Lateral View
– Radio-capitellar line shows the last 2-4cm of the radius
dissecting the capitellum. If passing anterior or posterior
then ? radial head dislocation.
– Anterior humeral line normally shows a J-shape or hockey
stick. A line drawn along the anterior humeral cortex
should have a third or more of the hockey blade
(capitellum) anterior to it. Loss of the hockey stick
appearance or less than a third of the blade suggests
supracondylar fracture.
– Also look for hourglass or figure 8 in the distal humerus.
Loss suggests fracture.
Elbow
Normal measures
Figure 8 or hour glass
Radiocapitellar line – pink
Anterior humeral line – yellow
Elbow
Alignment
• AP
– The radiocapitellar and coranoid-trochelar joint
spaces should be parallel and equal.
– A line through the centre of the proximal 2-4cm of
the radius should intersect the capitellum.
– About half of the radial head fractures are
undisplaced so it is important to look for subtle
changes
Elbow
Congruity
• The trochlea is congruous with the ulna
• The capitellum is congruous with or parallels
the articular surface of the head of the radius
Elbow
Soft Tissues
• Anterior fat pad is a thin elongated radiolucency
laying parallel to the distal humerus. Haemarthrosis
will cause displacement of this fat pad causing
appearance of the ‘sail sign’, indicative of a fracture
at the elbow.
• The posterior fat pad may be displaced by a very
large effusion and shows up as a thin black line
posterior to the cortex of the distal humerus
Elbow
Displacement of the fat pads of the elbow, indication of
a haemarthrosis usually due to a fracture
Black arrow indicating anterior and posterior indicated
by the white arrow
Shoulder
Shoulder
Glenohumeral Joint
• Standard views
– AP
– Y view
– Axial (Armpit) view or apical view
• Additional views
– Stryker notch view
– Supraspinatus outlet view
Shoulder
Acromioclavicular Joint
• Standard views
– AP of shoulder
• Additional views
– Weightbearing/distraction
– Zanca view
Shoulder
Alignment
• Glenohumeral Joint
– Humeral head should lie in the glenoid fossa and
the joint space should be equal top and bottom
– Loss of the features of the greater tuberosity and
bicipital groove across in internal rotation and is
known as the ‘light bulb sign’ and may be
indicative of a posterior dislocation.
– Mild inferolateral subluxation may be due to
haemarthrosis ? from a fracture
Shoulder
Alignment
• AC Joint
– Inferior margins of the lateral clavicle and the
acromion should be aligned. Note though 20% of
people may have some minor mal-alignment in
which case bilateral AC joint x-rays (+/weightbearing through AC joint) should be
undertaken to exclude widening of the joint.
Shoulder
Alignment
• Rockwood AC Joint Injury Classification
– Type 1 – no joint separation
– Type 2 - AC joint is disrupted with a slight vertical separation and there
is a slight increase in the CC interspace of <25%
– Type 3 - CC distance of 25-100% of other side
– Type 4 - lateral end of the clavicle is displaced posterior through
trapezius as seen on the axillary X-ray
– Type 5 - CC distance > 100% of other side (usually associated with
rupture of deltotrapezial fascia, resulting in subcutaneous distal
clavicle)
– Type 6 - rare injuries with the distal clavicle lying either in a
subacromial or subcoracoid postition (infero-lateral under conjoinded
tendon)
Shoulder
Alignment
• Subacromial Space
– Loss of acromiohumeral distance (<7mm) is
usually from extensive loss of rotator cuff
Shoulder
Bone
• Interpretation of the axial and Y-views are useful for
assessing for dislocation and also reviewing for
avulsion injuries from the glenoid rim and for
impaction injuries on the humeral head
• The trough line sign refers to a vertical or archlike
sclerotic line of cortical bone projecting parallel and
lateral to the articular cortical surface of the humeral
head. This occurs due to the anterior aspect of the
humeral head becomes impacted against the
posterior glenoid rim
Shoulder
Posterior Glenohumeral Joint Dislocation
Light Bulb Sign
Trough Line
Shoulder
Soft Tissues
• AC joint disruption is usually associated with
adjacent soft tissue swelling
• Intra-articular fractures of the humeral head
can lead to a lipohaemarthrosis
• Calcific tendonitis can be seen in the
subacromial space or at the supraspinatus
insertion to the humeral head.
Shoulder
Lipohaemarthrosis
Calcific Tendonitis
Shoulder
Soft tissue mass superior to clavicle and posterior to clavicle. Patient
presented for review of radiculopathy, as symptoms were unremitting
pain and paraesthesia into the right arm
CT showed primary lung cancer and widespread metastatic disease
Shoulder
• Neer’s Classification Of Proximal Humeral Fractures
–
–
–
–
1 Part = no significant displacement across fracture lines
2 Part = displacement across one fracture
3 Part = some displacement across 2 fractures
4 Part = serious displacement across 3 fractures, severe
comminution
Note displacement is considered separation >1cm or
angulation > 45 degrees
Neer’s Classifications
Shoulder
• The AO classification divides proximal humeral fractures into
three groups, A, B and C, each with subgroups, and places
more emphasis on the blood supply to the articular surface.
• The assumption is that if either the lesser or greater
tuberosity remains attached to the articular segment, then
blood supply is probably adequate to avoid AVN
Pelvis and Hip
Pelvis and Hip
Pelvis
• Standard views
– AP
• Additional views
– Judet (oblique)
– Inlet
– Outlet
Pelvis and Hip
Hip
• Standard views
– AP of both hips
– Lateral
• Additional views
– Frogleg lateral
Pelvis and Hip
Alignment
• 3 circles of the pelvic rim = pelvic rim and the 2
obturator foramina.
• Shenton’s line is formed by a line running from the
the inferior border of the pubic ramus (ie top of
obturator foramin) along the medial border of the
neck of femur. If disrupted it is often from a #NOF
rather than pelvic fracture.
• For acetabular review use the iliopectineal line,
ilioischial line (Kohler's line) and teardrop line.
• If there is disruption in at one point in the circle be
sure to check other areas as a second disruption is
very common.
Pelvis and Hip
Pelvis and Hip
• Standard views
– Pelvis = AP
– Hip = AP and lateral
• Additional views
– Pelvis = Judet views, inlet and outlet views
– Hip = frog legged view
Pelvis and Hip
• Injuries of interest
– Avulsion injuries may occur in teenagers at the ASIS (rectus
femoris), greater trochanter (gluteus medius) and lesser
trochanter (iliopsoas). Less common are ligamentous
avulsions and are generally found at the lateral border of
the sacrum or ischial spines.
– Metatastic disease and pathological fractures are generally
found in the proximal femur, particularly subtrochanteric
region.
– Risk of avascular necrosis post intracapsular hip fractures
or associated with longterm oral steroid use or deep sea
diving.
Knee
Knee
Knee
• Standard views
– AP
– Lateral
• Additional views
– Skyline
– Tunnel or Notch
– Internal and External Oblique
Knee
Alignment
• AP
– Lateral tibial line (lateral edge of tibia and lateral
edge of the femoral condyle should be aligned)
can assess for tibial plateau fractures
– The tibial plateau is not flat but slopes at about
15° downwards from anterior to posterior.
– Look for step deformity or sclerotic lines/loss of
trabecular pattern to suggest tibial plateau
fracture
Knee
Alignment
• Lateral
– The tibial plateau and femoral condyles should be
aligned, anterior or posterior displacement would
suggest loss of cruciate ligament integrity
Knee
Knee
Soft tissues
– On the lateral view the presence of a
lipohaemarthrosis would suggest the existence of
a fracture
– Fluid in the knee joint causes enlargement of the
suprapatellar bursa which will separate the
prefemoral and suprapatellar fat pads to be
separated
Knee
• Signs of ligamentous injuries of the knee
– Segond fracture = Lateral capsular ligament avulses
part of the lateral tibial plateau
– Anterior tibial eminence or tibial spine avulsion = ACL
avulsion
– Pelligrini-Steida lesion = chronic recurrent injury to
MCL
– Avulsion of poles of patella or tibial tuberosity =
quadriceps/patellar tendon avulsion
– Avulsion of fibular styloid process = avulsion of LCL or
biceps femoris
Knee
Segond Fracture
Knee
Pelligrini-Steida Lesion
Knee
• Patella dislocation
– Risk factors are:
•
•
•
•
Patella alta
High Q angle
Shallow patellofemoral groove
Genu valgum
– Associated injuries include avulsion injuries to the
patella or osteochondral defects to the
patellafemoral joint surfaces
Knee
• Fibula head fractures
– May need to check for this injury with associated
injury such as tibial plateau fracture or ankle
fracture (eg Maisonneuve Fracture)
Ankle
Ankle
Ankle
• Standard views
– Lateral
– AP or Mortice view (AP at 20° internal rotation)
• Additional views
– Calcaneal view
– Broden’s view
– Stress views
– Internal and External Oblique views
Ankle
Ottawa Ankle Rules
• X-ray is indicated when on clinical examination
the patient presents with either:
– Tenderness at the tip or the posterior edge over
the last 6cm of the distal fibula or tibia
– Bony tenderness of the medial malleolus
– Tenderness at the base of the fifth metatarsal
– Unable to weightbear immediately after injury or
in Emergency Department
Ankle
Ankle
Alignment
• AP
– The joint space should be uniformly spaced at < 4mm and
clearspace <5mm
– Normal talar tilt = -1.5 to +1.5° (ie close to parallel)
– Talocrural angle = 83°+/- 4°
• AP Mortise view
– Tibiofibular overlap should be >10 mm
– Tibiofibular clearspace (distance between lateral border of
posterior tibia & medial border of fibula, 1cm above the
joint line) should be <5 mm
Ankle
Clearspace
Overlap
Ankle
90
Talocrural
angle
Ankle
Alignment
• Lateral
– The long axis of the tibia and fibula should overlap and
bisect the talar dome.
Ankle
• Often on the AP view injuries, such as an
oblique fracture through the distal fibula, can
appear normal.
• On the lateral view close attention should be
paid to look for subtle abnormalities that can
signify unstable ankle injuries.
Ankle
• On the lateral view close attention should be paid to
particular areas:
1.
2.
3.
4.
5.
6.
7.
Lateral malleolus
Tibial plafond
Posterior malleolus
Superior surface of the talus and navicular
Calcaneus
Anterior process of the calcaneus
Base of the fifth metatarsal
Ankle
1
3
2
4
6
7
5
Foot
Foot
• Standard views
– AP
– Oblique +/- Lateral (mediolateral)
• Additional views
– Canale view (Maximal PF and Inv 15°)= talar neck
– Harris-Beath view = body of calcaneous, middle
and posterior facets of the subtalar joint
– Broden’s view = generally CT used instead
Foot
Foot
Alignment
• Lateral view
– The superior surface of the talus, navicular, medial
cuneiform and first metatarsal lie in a straight line.
– Bohler’s angle lies between the plane of the
posterosuperior and anterosuperior surfaces of
the calcaneus = 28-40° and <28 ° generally follows
a calcaneal compression fracture
Foot
Foot
Alignment
• The cyma line can be seen on lateral, AP and
oblique images.
• This represents an intact midtarsal joint. Note
that disruption of the smooth curve is not
always a traumatic injury and can occur in
marked pes planus.
Foot
Cyma Line
Foot
Alignment
• AP – the 2nd MT should align with the medial
aspect of the middle cuneiform.
• Oblique
– the medial aspect of the 3rd MT should align with the
medial aspect of the lateral cuneiform
– The medial aspect of the 4th MT should align with the
medial aspect of the cuboid
• Loss of alignment could suggest injury such as
Lisfranc injury
Foot
Foot
Foot
• Calcaneal Fractures
– 60% of fractures in the foot
– Often comminuted and often may require CT to
show the full extent of the injury
– 25% of calcaneal fractures are extra articular =
anterior process, posterior process (beak) and
tuberosity
Foot
• Talus Fractures
– Avulsion fractures are the most common at 50%,
while neck fractures are 30%
– Neck fractures usually result from high velocity
impaction injuries
– Risk of AVN with this injury
– May have associated subtalar disolcation which
will show as loss of smooth cyma line
Foot
• Navicular fracture
– Avulsion superiorly or medially by posterior tibialis
are the most common
Foot
• Stress fractures can occur in the foot and
generally occur at:
– Sesamoids under hallux
– First base of MT
– Neck of 2-4th MTs
– Base of 4th and 5th MTs
– Cuneiforms, navicular and cuboid
Foot
• Stress fractures may show up as periosteal
reaction.
• Often will not show up on initial onset and xrays weeks later will start to show reaction if
at all – may require MRI or bone scan
Fracture
• Description
–
–
–
–
–
–
–
–
–
–
–
Open versus closed
Complete versus incomplete
Fracture plane (transverse, oblique, spiral, avulsion)
Displacement of distal fragment
Angulation (direction of fracture angle apex)
Comminution
Overriding fragments, limb shortening or distraction
Articular relation (intra or extra articular)
In pediatric population: involvement of physis
Associated subluxation/dislocation
Location ie body part, bony, region of the bone, anatomical
region
Bone Lucency Lesions
• Most important determinates in assessing bone
lucencies are:
– the morphology of the bone lesion on a plain radiograph
• Well-defined vs ill defined osteolytic
• Sclerotic
– Age of patient
• Other factors may include location on the bone
• A good reference is:
http://www.radiologyassistant.nl/en/p494e15cbf0d8
d
Bone Lucency Lesions
Image from www.radiologyassistant.nl/en
ABC = Aneurysmal bone cyst, CMF = Chondromyxoid fibroma, EG = Eosinophilic Granuloma,
GCT = Giant cell tumour, FD = Fibrous dysplasia, NOF = Non Ossifying Fibroma HPT =
Hyperparathyroidism with Brown tumour, SBC = Simple Bone Cyst
Bone Lucency Lesions
Image from www.radiologyassistant.nl/en
Bone Lucency Lesions
Image from www.radiologyassistant.nl/en
Aggressive vs Benign Bone Processes
• Edge of lesion/ Zone of transition
– Benign:
• sharply defined, may be sclerotic
– Aggressive (infection, tumour):
• poorly defined, almost blends into the surrounding
bone, wide transition zone
• Sometimes the abnormality is multifocal and the bone
appears ‘moth eaten’.
Aggressive vs Benign Bone Processes
Image from www.radiologyassistant.nl/en
Narrow Zone of Transition
Aggressive vs Benign Bone Processes
Image from www.radiologyassistant.nl/en
Wide Zone of Transition
Aggressive vs Benign Bone Processes
• Periosteal Reaction.
– Benign:
• No or smooth periosteal reaction
– Aggressive:
• Periosteal reaction with a less organized appearance eg
sunburst or lamellar reaction.
• This is an acute periosteal reaction that has not had
time to reorganise itself
Aggressive vs Benign Bone Processes
Osteosarcoma
Image from www.radiologyassistant.nl/en
Ewing Sarcoma
Infection
Lamellated Reaction
Multilayered Reaction
Aggressive vs Benign Bone Processes
• Cortical Destruction.
– Benign:
• No cortical destruction, but may be expanile causing
thinning of the cortex
– Aggressive:
• Malignant lesions may destroy the cortex.
Septic Arthritis
• Very aggressive pathology
• Patient will complain of
systemic illness such as fevers,
night sweats, malaise
• Very painful and marked
limitation to movement of the
joint and palpation.
Paget’s Disease
• Paget’s disease of bone is common, affecting up to
4% of Australians over the age of 55 years.
• The cause of Paget’s disease is unknown, but there is
a strong genetic influence.
• It is a chronic condition that causes abnormal
enlargement and weakening of bone.
• Most common sites affected include the skull, spine,
pelvis, thigh bone, shin and the bone of the upper
arm.
Paget’s Disease
Osteoarthritis
• Radiographic evidence of OA does not
correspond well with patient symptom
severity, but it is true to say the more
extensive the changes on xray the more likely
the patient is to have symptoms.
• NWB films can underestimate the extent of
OA in lower limb joints.
• Most common grading is the KellgrenLawrence System
Osteoarthritis
Osteoarthritis
Kellgren Lawrence OA Grading
Grade 1: doubtful narrowing of joint space and possible
osteophytic lipping
Grade 2: definite osteophytes, definite narrowing of joint
space
Grade 3: moderate multiple osteophytes, definite narrowing
of joints space, some sclerosis and possible deformity of
bone contour
Grade 4: large osteophytes, marked narrowing of joint
space, severe sclerosis and definite deformity of bone
contour
Osteochondral Defects
• Generally more prevalent in lower limb joints, such
as the ankle on talar dome and knee on tibiofemoral
or patellofemoral joint surfaces.
• Also can occur post dislocation in any joint eg HillsSach lesion in shoulder dislocation is technically a
OCD.
• May not be evident on plain films and may require
CT or MRI. MRI may show whether the lesion is
‘active’ or not, as OCD may be asymptomatic.
Osteochondral Defects
Extremely large OCD on medial aspect of the talus
Osteochondral Defects
Extremely large OCD in the elbow joint
Online Resources
• Here are some websites to help get exposure to various
pathologies and some good resources to extend knowledge:
– www.auntminnie.com
– www.auntminnieeurope.com
– www.radiopaedia.org
– www.radiologyassistant.nl/en/
– www.rad.washington.edu/academics/academicsections/msk/teaching-materials/online-musculoskeletalradiology-book/
– www.mypacs.net