Imaging Flashcards
calcific tendonitis
bony bankart lesion
anterior shoulder dislocation
hill sachs lesion
EDH
SDH
bamboo spine - AS
squaring of vertebral bodies - AS
Scotty dog (oblique XR) of spondylolysis
spondylolisthesis
Osteophytes - Knee
The formation of osteophytes (bone spurs) is a common feature of osteoarthritis
This AP view of the knee shows osteophytes of the tibia and femur
Small osteophytes have also formed at the tibial spines (tibial spiking)
The knee joint spaces are narrowed and irregular
articular surface cortical irregularity and sclerosis (OA)
The joint space is narrowed and the cortical surface is irregular
Increased density of the articular surface indicates sclerosis
Small sub-cortical cysts have formed
sub cortical cyst (OA)
Although sub-cortical bone cysts are a characteristic finding of osteoarthritis, they are only visible in approximately one third of X-rays of osteoarthritic joints
This hip joint is narrowed and large osteophytes have formed
Note: These cysts may be called ‘sub-chondral cysts’, ‘sub-cortical cysts’, or ‘geodes’ – any of these terms are acceptable
Multiple osteoarthritic changes
Large osteophytes (arrowheads) have formed at the joints of the fingers
These osteophytes correspond to the clinical finding of bony swelling at the distal interphalangeal joints (Heberden’s nodes) and the proximal interphalangeal joints (Bouchard’s nodes)
The joints are severely narrowed (arrows)
Large sub-cortical cysts have also formed in this patient with severe osteoarthritis of the finger joints
The ring could no longer be removed
OA
Intra-articular loose bodies
In some patients calcified loose bodies may be seen within an osteoarthritic joint
These are fragments of bone or cartilage which have detached from the joint surfaces and remain in the joint capsule
This lateral view of the knee also shows severe osteoarthritis of the patellofemoral joint which is very narrow
DDD C spine
Narrowing of the space between the vertebral bodies indicates reduction of height of the intervertebral discs
Osteophytes have formed and the adjacent vertebral body endplates are sclerotic and irregular (compare with the normal endplates more superiorly)
DDD L spine
The disc spaces are narrow due to reduction of disc height
Prominent vertebral body osteophytes have formed anteriorly
Cortical irregularity of the facet joints is a sign of facet joint arthrosis
Note: The intervertebral disc spaces are not synovial joints and so osteoarthritis is an incorrect term for degenerative disc disease. However, the facet joints are synovial joints and so are susceptible to osteoarthritis – often referred to as ‘arthrosis’.
DDD L spine
This T2-weighted MRI image shows reduced fluid signal within the discs; the discs appear blacker than usual – compare with the normal disc at T12/L1
The discs are bulging and reduced in height
The endplate surfaces appear irregular and prominent osteophytes have formed (arrowheads)
US of metacarpophalyngeal joint erosion in RA
A large erosion is seen at the margin of the joint
Pannus (synovial proliferation) is seen filling the joint capsule
Marginal erosions in RA
Large erosions have formed at the margins of the thumb metacarpophalangeal joint
The marginal erosions seen in rheumatoid arthritis differ from the sub-cortical cysts seen in osteoarthritis which are located deep to the articular surfaces of joints
ulnar deviation in severe RA
The joint spaces of the wrist are narrowed and there is severe erosion of the carpal bones
At the metacarpophalangeal joints the tendons of the hand pull the subluxed fingers towards the ulnar side – this correlates with the clinical sign of ulnar deviation
RA
Large peri-articular erosions have formed around the humeral head
Erosion of the distal clavicle – a classic feature of advanced rheumatoid arthritis affecting the shoulder – causes widening of the acromioclavicular joint (asterisk)
RA
The acetabulum is eroded such that the femoral head (red line) encroaches medial to the inner rim of the pelvis (green line) – compare to the normal position of the right femoral head (white line)
‘Protrusio acetabuli’ – protrusion of the femoral head medially through the acetabulum – is a classic feature of advanced rheumatoid arthritis affecting the hip
Atlanto-axial subluxation
Rheumatoid arthritis can result in erosion of the odontoid peg in the cervical spine
The odontoid peg becomes more pointed than normal due to erosion resulting in a ‘candy-licked’ appearance
These lateral images of the cervical spine taken with the neck in flexion and extension show a large gap forming between the odontoid peg and the anterior arch of the atlas on flexion
This gap indicates that the stabilising ligaments of the anterior atlanto-axial joint are no longer intact
gout First metatarsophalangeal joint
A juxta-articular erosion has formed in the head of the first metatarsal
Soft tissue swelling due to inflammation is a common finding in active gout
Gouty tophi
Speckled increased density of peri-articular soft tissue is due to deposition of monosodium urate crystals within a gouty tophus
CPPD – Chondrocalcinosis
Chondrocalcinosis is visible in the knee menisci of this patient with CPPD
CPPD – Sub-cortical cyst
This detail image of the lateral compartment of the knee shows chondrocalcinosis and formation of a large sub-cortical cyst
sacroiliitis
Asterisks = Iliac bones
These MRI images show decreased fat signal (T1 image) and increased fluid signal (STIR image) due to bone oedema adjacent to the sacroiliac joints bilaterally
These are typical features of an active sacroiliitis
MRI evidence of sacroiliitis supports the diagnosis of ankylosing spondylitis if this diagnosis is suspected clinically
The plain X-rays were completely normal in this patient
romanus lesions - early finding in inflammatory spondyloarthropathies, such as ankylosing spondylitis and enteropathic arthritis
A T2 weighted (water sensitive) MRI image is shown next to the plain X-ray
The plain X-ray shows sclerosis at the corners of two vertebral bodies
These ‘shiny corners’ are chronic Romanus lesions – they are not clearly visible on the MRI as sclerosis appears black on all types of MRI images
The MRI image shows multiple small foci of high signal (fluid) in the bone marrow of the adjacent vertebral body corners (arrowheads)
This fluid represents bone marrow oedema caused by enthesitis at the point of insertion of the longitudinal spinal ligaments
Several other foci of bone oedema seen at the corners of other vertebral body corners are due to developing Romanus lesions which are not yet visible on the plain X-ray
AS - bamboo spine
Flowing syndesmophytes are seen fusing the cervical spine vertebral bodies anteriorly leading to the classic ‘bamboo spine’ sign – the fused spine resembles bamboo
In this patient the facet joints of the spine have also fused
Pt is 25 y/o
psoriatic arthritis
This young patient (25 years old) with psoriatic arthritis has severe narrowing of the hip joint space with large osteophytes and sub-cortical cysts
The appearances are identical to changes seen in osteoarthritis, but onset is typically at a younger age and progression tends to be more rapid
pencil cup deformity in psoriatic arthritis
Severe erosions may be seen in joints of the fingers and toes such that joints can be destroyed resulting in severe deformity
The severe joint erosion in this patient’s finger progressed over a period of 4 years – erosion is seen in both the middle phalanx (MP) and the distal phalanx (DP) of the finger
The middle phalanx is narrowed, like a pencil, and the distal phalanx is eroded centrally, like a cup, hence ‘pencil-in-cup’ deformity
Note: Similar erosion may occur in a septic arthritis but progresses more rapidly
AVN femoral head - MRI (T1 image - fat sensitive image)
Plain X-ray was normal in this patient
The MRI shows a geographic line of low signal which passes across the femoral head deep to the weight-bearing articular surface
AVN femoral head
A lucent geographic line undermines the articular weight-bearing surface of the femoral head
The femoral head articular surface subsides and is flattened
AVN femoral head
The femoral head articular surface has been destroyed
The cortex of the acetabulum articular surface is thinned and flattened
Freiberg’s infraction
The articular surface of the distal phalanx of the second toe metatarsophalangeal joint appears flattened
Linear lucency and sclerosis passes across the metatarsal head and undermines the articular surface
Keinbock’s dz (AVN of lunate)
The lunate bone has become very sclerotic and is flattened in this patient with longstanding Keinbock’s disease (AVN of the lunate bone)
Periosteal reaction in osteosarcoma
Periosteal reaction is an aggressive feature seen in malignant bone disease and infection
Sometimes periosteal reaction has a ‘sunburst’ appearance
Periosteal reaction may also result in the appearance of a triangle of new bone seen lifting away from the cortex surface (Codman’s triangle)
Sunburst and Codman’s triangle periosteal reaction are aggressive features associated with high likelihood of a malignant process
sclerotic bony met
A solitary area of sclerosis (increased bone density) is seen in the pelvis of this patient with metastatic breast cancer
lytic bony met
A focus of low density is seen within the bone marrow of the femur
The upper and lower edges are poorly defined (wide zone of transition)
This was a lytic (bone destructive) lesion in a patient with lung cancer
multiple myeloma
Multiple myeloma is a disease which commonly presents with multiple lytic bone lesions at the time of diagnosis
Strictly speaking these are not metastases but rather the manifestation of multiple lesions arising throughout the axial skeleton
Lesions arise from bone marrow and cause characteristic ‘punched-out’ lytic foci
pathologic # of lesser trochanter
There are patchy areas of increased density (sclerosis) and decreased density (lysis) resulting in a ‘moth-eaten’ bone texture in the pelvis and proximal femur
The lesser trochanter is detached – this is the site of insertion of the iliopsoas tendon
This injury is rarely seen in the absence of bone metastases
heel ulcer + osteomyelitis
The skin and subcutaneous soft tissue are deficient at the site of a skin ulcer
Infection has passed down to the bone surface of calcaneus which is eroded
osteomyelitis in diabetic
Bone density is reduced in the 1st metatarsal head and the adjacent proximal phalanx
The 1st metatarsal bone is shortened due to a pathological fracture of the 1st metatarsal head
osteoporotic wedge # T spine
All the bones appear of reduced density (blacker than normal)
One of the vertebral bodies of the T-spine has collapsed
This fracture is often described as a wedge fracture
osteoporotic biconcave #
all the bones appear of reduced density (blacker than normal)
Depression of the central parts of the vertebral body endplate surfaces results in a biconcave appearance
This is another common pattern of insufficiency fracturing of vertebral bodies in patients with osteoporosis
osteomalacia (softening of bone d/t low calcium + vit D intake) related pseudofracture
A line passes into the femoral neck, but not across it
Increased bone density surrounds this line due to healing
The patient had hip pain without a history of trauma
These are typical features of a pseudofracture/Looser’s zone
Paget’s disease - Paget’s disease of bone is a chronic disorder of bone remodeling characterized by increased bone turnover, leading to structurally disorganized and weakened bone. It typically affects older adults and commonly involves the skull, spine, pelvis, and long bones.
The femur is expanded with thickening of the cortex and a coarsening of the trabecular pattern
The shaft of the femur is deformed
The entire right hemipelvis appears abnormal – compare with the normal left hemipelvis
The cortex is thickened, and the trabecular pattern is coarsened
The whole bone is involved
The lower image shows collapse of the arch of the foot
Despite the severe deformity this diabetic patient had no pain in the foot
charcot foot
The bones are no longer aligned correctly
Arterial calcification is another feature commonly seen on X-rays in patients with diabetes
achilles tendon tear
The upper image shows the normal structure of a tendon – the Achilles tendon is used as an example
Ultrasound clearly demonstrates the normal fibre structure of the intact tendon
The lower image shows a large gap in the tendon fibres
Because the tendon is under tension, when it ruptures the fibres retract distally and proximally to form a gap
The gap is filled with blood (haematoma) in this acute complete Achilles tendon rupture
achilles tendonopathy
Tendinopathy (also known as tendinosis or tendinitis) results in thickening of the tendon
The lower image shows an area where Doppler ultrasound has been applied (green box)
Doppler ultrasound shows pulsating areas of movement (small coloured areas) within the tendon indicating increased blood supply (hypervascularity)
tenosynovitis of wrist flexor tendons
Ultrasound and Doppler ultrasound show swelling and hypervascularity of soft tissues surrounding the tendons of the wrist indicating severe tenosynovitis – inflammation of the tendon sheath
shoulder US
subacromial bursitis
The subacromial-subdeltoid bursa of the shoulder is a normal thin fluid-filled space which allows smooth movement of the rotator cuff tendons under the deltoid muscle and the acromial arch
This ultrasound image demonstrates a layer of low reflectivity (black) located between the supraspinatus tendon and the deltoid muscle
The depth of fluid is greater than normal – the deltoid muscle should contact the superior surface of the supraspinatus tendon
Excess fluid in the subacromial-subdeltoid bursa is associated with rotator cuff tears (allowing fluid to pass from the glenohumeral joint into the subacromial bursa) or with bursitis – inflammation of the bursa
calcific tendonitis
Deposition of Calcium Hydroxyapatite crystals in soft tissues results in foci of high density visible on X-ray images
This phenomenon is commonly known as calcific tendinopathy – a manifestation of HADD
Dermatomyositis manifests as ‘sheet-like’ calcifications visible with X-ray
myositis ossificans
Myositis is an uncommon complication of trauma resulting in bone-like calcifications forming within muscles
In this image a large area of calcification is visible within the quadriceps compartment of the thigh
Colle’s #
pelvic diastasis
AVN scaphoid
AC separation
The inferior surfaces of the clavicle and acromion are not aligned - indicating disruption of the acromioclavicular ligaments
The coracoclavicular distance is also wide - indicating coracoclavicular ligament injury
anterior shoulder dislocation AP view
Humeral head and glenoid surfaces are not aligned
The humeral head lies below the coracoid
anterior shoulder dislocation Y view
The humeral head lies anterior to the glenoid and inferior to the coracoid process
anterior shoulder dislocation axial view
The humeral head surface is no longer aligned with the glenoid
The humeral head lies anterior to the glenoid
Bilateral shoulder pain following epileptic fit
posterior shoulder dislocation AP view
The glenohumeral joint is widened
Cortical irregularity of the humeral head indicates an impaction fracture
Following posterior dislocation the humerus is held in internal rotation and the contour of the humeral head is said to resemble a ‘light bulb’
Note: Any X-ray acquired with the humerus held in internal rotation will mimic this appearance
posterior shoulder dislocation Y view
The humeral head (blue line) no longer overlies the glenoid (red line)
The correct position of the humeral head is shown (green line)
scapula #
Displaced fracture of the scapula lateral border
Fracture line passing through the scapula body
bony bankart (glenoid #)
A bone fragment is seen lying adjacent to the incomplete rim of the glenoid
humerus #
Transverse fractures of the surgical neck (red line)
Fracture line (yellow) causing separation of the greater tubercle
Trivial trauma to upper arm
Known history of multiple myeloma
Pathological fracture of humeral shaft
Poorly defined lytic lesion of the humerus shaft
Fracture with varus angulation (not clearly visible on the lateral image)
normal elbow XR 10 y/o
The red ring shows the position of the External or ‘Lateral’ epicondyle (L) which has not yet ossified
C = Capitulum
R = Radial head
I = Internal epicondyle
T = Trochlea
O = Olecranon
normal elbow XR 7 y/o
Normal anterior fat pad
The posterior fat pad is not visible - soft tissue of the triceps muscle is not separated from the posterior edge of the humerus
More than one third of the capitulum lies in front of the anterior humerus line
normal elbow XR 7 y/o
The first three ossification centres are visible
C = Capitulum
R = Radial head
I = Internal epicondyle
The Trochlea (T) has not yet ossified (Red ring = predicted position)
IMPORTANT RULE: Suspect avulsion of the internal epicondyle if it is absent and there is ossification at the site of the trochlea
radial head #
The lateral image shows the anterior fat pad is raised away from the humerus but does not show a fracture
Posterior fat pad visible - ALWAYS ABNORMAL
A fracture of the radial head is visible on the AP image
supracondylar #
Child patient
Visible fracture of the distal humerus
A joint effusion (haemarthrosis) raises the fat pads away from the humerus
The powerful triceps muscle posteriorly displaces the ulna - taking the capitulum (C) with it
The capitulum therefore lies well behind the anterior humerus line
At least one third of the capitulum should lie in front of the anterior humerus line
Elbow X-ray - Radial head dislocation
The radiocapitellar line does not pass through the capitulum
In this case the ulna is also dislocated from the trochlea
Distal radius fracture - Dorsal displacement
Transverse fracture of the distal radius
Dorsal angulation and displacement of the wrist results in a so called ‘dinner fork’ deformity
Shortening results in a very narrowed ulnocarpal space (asterisk)
This injury (or similar) - most common in elderly osteoporotic women - is often referred to as a ‘Colle’s fracture’
Distal radius fracture - Palmar displacement
Palmar (volar) displacement and angulation
Shortened radius
This injury is often referred to as a ‘reverse Colle’s’ fracture or ‘Smith’s’ fracture
Distal radius fracture - Comminuted
High degree of comminution of the distal radius and a displaced fracture of the ulnar styloid
A fracture involving the articular surface with dorsal displacement of the wrist bones can be referred to as a Barton’s fracture
Some may call this a type of Colle’s fracture
Note: This image demonstrates why eponyms are best avoided unless the meaning is clear - a full description is usually best
Forearm fracture/dislocation - Monteggia type
Displaced fracture of the ulna with shortening
Loss of alignment of the radiocapitellar line due to dislocation of the radial head
Note: The radiocapitellar line should pass through the middle of the capitulum (C)
Greenstick fracture
The palmar (volar) cortical surface of the radius is buckled
There is a visible fracture through the dorsal cortex of the radius
Normal ulna
Torus fracture
Buckled radius
No visible fracture line
Wrist bones - Normal X-ray (PA)
The pisiform and triquetrum overlap
The other carpal bones partly overlap
Wrist bones - Normal X-ray (Lateral)
Multiple wrist bones overlap
The scaphoid (red) is difficult to see clearly on this view
IMPORTANT NOTE: This view is essential to check for alignment of the radius, lunate and capitate (blue)
Scaphoid fracture - (Ulnar deviation view)
Wrist stressed towards the ulnar side
Transverse fracture of the scaphoid waist
Triquetrum fracture - (Lateral view)
Comminution of the dorsal cortex of the triquetrum
Soft tissue swelling over the dorsum of the wrist
Hamate fracture - (Oblique scaphoid view)
Fracture line through the hamate
This injury was only visible on this view
Wrist joints - Normal X-ray
The intercarpal, radiocarpal, distal radioulnar and carpometacarpal joint spaces are aligned closely and evenly
Normal scapholunate space
Ulnar deviation view (wrist stressed towards the ulnar side)
The normal scapholunate space (arrowheads) is similar in width to other normal intercarpal joints (arrows)
Scapholunate widening
Ulnar deviation view (wrist stressed towards the ulnar side)
Widening (arrowheads) of the scapholunate distance >2 mm - the space is obviously wider than the other intercarpal spaces (arrows)
This results in the ‘Terry Thomas sign’ - in homage to the well known British actor
Widening if the scapholunate space indicates a tear injury of the scapholunate ligament
Peri-lunate dislocation
Normal alignment of the radius - lunate - capitate on the left for comparison
The right image shows dorsal dislocation of the capitate which should be congruous with the cup of the lunate
normal lateral wrist view
Bones of the hand - Normal X-ray (PA)
Finger bones articulate at the metacarpophalangeal joints (MCPJ), the proximal interphalangeal joints (PIPJ) and the distal interphalangeal joints (DIPJ)
The fingers each have 3 phalanges - proximal - middle and distal
The thumb has only 2 phalanges - proximal and distal - joined by the interphalangeal joint (IPJ)
Finger dislocation
The proximal phalanges are dislocated at the 4th and 5th MCPJs
Boxer’s fracture
Boxer’s fracture
Close observation shows an oblique fracture
show soft tissue swelling - often a useful sign of a finger fracture
Bennett’s type fracture
The thumb metacarpal base intra-articular fracture is much more easily seen on the oblique image
This injury is termed a ‘Bennett’s’ type injury - as in this case there is invariably a degree of subluxation/dislocation of the metacarpal base
Mallet finger injury X-ray
Dorsal avulsion of the distal phalanx base
Soft tissue swelling
In this case the extensor tendon is intact
normal clavicle
Clavicle - Fracture
Transverse/oblique mid shaft fracture
Inferior displacement of the distal clavicle
Acromioclavicular joint (ACJ) - Normal
The inferior margins of the acromion and clavicle are well aligned (red lines) indicating integrity of the acromioclavicular ligaments (not visible - position shown by blue lines)
The coracoid is not widely separated from the clavicle - this indicates integrity of the coracoclavicular ligaments (not visible - position shown by orange lines)
Shoulder - Normal AP view
The humeral head and glenoid contours are aligned normally
Shoulder - Normal Y-view
The Y-view is so named because of the Y shape of the scapula formed when looking at it laterally
The humeral head is correctly aligned - it overlies the glenoid and is positioned posterior to the coracoid
Shoulder joint - Normal axial view
The glenohumeral joint (GHJ) is aligned normally
The acromioclavicular joint (ACJ) is aligned normally
Scapula - Normal
Anatomical parts of the scapula include - body, neck, glenoid, coracoid, spine and acromion
The scapula body has lateral, medial and superior borders
Order of elbow ossification centre development
C - Capitulum (or Capitellum)
R - Radial head
I - Internal epicondyle (or medial epicondyle)
T- Trochlea
O - Olecranon
L - Lateral (or external epicondyle)
What are the key features on XR of OA?
Key features of osteoarthritis
Joint space narrowing
Osteophytes
Articular irregularity and/or sclerosis
Sub-cortical cysts (geodes)
Intra-articular loose bodies
Note: Erosions are NOT a feature
Joint space narrowing - OA
The medial side of the knee joint is severely narrowed such that the femur and tibia are touching
The lateral side of the joint is widened and there is abnormal (varus) angulation of the tibia
Increased density indicates articular surface sclerosis
Key features of DDD
Disc space narrowing
Disc bulging
Osteophytes
Endplate irregularity and sclerosis
Key features of RA
Erosions
Synovitis/pannus
Deformity
Symmetrical pattern
Narrow zone of transition – Non-ossifying fibroma
This bone lesion has a narrow zone of transition – a well-defined thin rim of sclerosis separating normal and abnormal bone
This is a non-aggressive feature
These are the typical appearances of a non-ossifying fibroma – a developmental abnormality
Note: This asymptomatic bone abnormality was discovered incidentally following an ankle injury
Wide zone of transition – Osteosarcoma
The bone texture is very abnormal distally – the normal trabecular pattern is replaced by small irregularly-shaped holes
The term ‘moth-eaten’ is often used to describe this type of abnormal bone texture
The bone texture appears normal more proximally
It is not possible to define a point at which normal bone becomes abnormal – the ‘zone of transition’ is wide
Biopsy proved this bone lesion to be a primary osteosarcoma
Heterotopic ossification
Heterotopic ossification is the formation of bone spurs and foci of calcification within soft tissues
This phenomenon is most common around the greater trochanter region following total hip replacement (THR)
In this image large bone spurs arise from the greater trochanter of the femur which severely restrict the range of hip movement
normal child knee XR
Systematic approach to imaging interpretation
Patient and image details
Bone and joint alignment
Joint spacing
Cortical outline
Bone texture
Soft tissues
Loss of bone alignment at the middle toe metatarsophalangeal joint due to dislocation
Alignment and joint spacing elsewhere is normal
normal proximal femur
Well defined trabecular pattern visible forming the femoral neck architecture
Distortion of this trabecular pattern may make an abnormality more conspicuous
tib plateau #
Joint effusion containing fat and blood (lipohaemarthrosis) that has leaked from bone following trauma
Visible fracture line - much less conspicuous than the lipohaemarthrosis
right neck of femur #
This image of the pelvis shows subtle irregularity of the cortical outline of the right femoral neck
Comparison with the other side - which is asymptomatic - increases confidence of a genuine abnormality
There is also loss of the normal trabecular pattern indicating a fracture (#)
fractured right neck of femur
Large calcified uterine fibroid
Loss of normal cortical contour of the femoral neck
Minor narrowing of the subacromial space (arrowheads) - suggesting rotator cuff disease which is a very common cause of shoulder pain
It would be easy to consider this the only abnormality if not checking the image systematically
Unexpected apical lung mass (pancoast tumor)
Hip X-ray anatomy - Normal AP
Shenton’s line is formed by the medial edge of the femoral neck and the inferior edge of the superior pubic ramus
Loss of contour of Shenton’s line is a sign of a fractured neck of femur
IMPORTANT NOTE: Fractures of the femoral neck do not always cause loss of Shenton’s line
Hip X-ray anatomy - Normal Lateral
The cortex of the proximal femur is intact
The Lateral view is often not so clear because those with hip pain find the positioning required difficult
Intracapsular fracture - Subcapital - AP
(Same case as below)
Shenton’s line is disrupted
Increased density of the femoral neck is due to overlapping - impacted bone
The lesser trochanter is more prominent than usual - due to external rotation of the femur
Intracapsular fracture - Subcapital - Lateral
Loss of integrity of cortical bone indicates fracture
Trabecular bone of the femoral neck overlaps
What does this show?
Garden classification
I - Incomplete or impacted bone injury with valgus angulation of the distal component
II - Complete (across whole neck) - undisplaced
III - Complete - partially displaced
IV - Complete - totally displaced
Garden IV fracture
Loss of Shenton’s line
Complete fracture of the full diameter of the femoral neck
Total displacement of the 2 fracture components
Intertrochanteric fracture
A fracture line runs between the trochanters
There is comminution with separation of the lesser trochanter
Note the fracture does not involve the femoral neck
Subtrochanteric fracture
This fracture passes distal to the trochanters
The femoral neck remains intact
Hip dislocation - AP
The femoral head lies superior and lateral to the acetabulum
No associated fracture is visible in this case but significant soft tissue injury is likely
Femoral shaft fracture
Spiral fracture with posterior angulation, lateral displacement and shortening
There is rotation of the distal femur so the knee faces laterally
X-rays of the proximal femur (not shown) did not reveal further injury
Injury occurred in a road traffic crash
normal knee XR
Knee - Normal Lateral (Horizontal Beam)
The Horizontal Beam Lateral view is useful for assessing soft tissues as well as bones
The quadriceps and patellar tendons are visible
Note the normal suprapatellar pouch between fat pads above the patella (asterisks) - widening of these fat pads or increased density in this area can indicate a knee joint effusion
Knee - Normal ‘Skyline’ view
Not usually indicated in the context of trauma
More helpful to assess knee pain due to suspected patellofemoral compartment osteoarthritis
Normal patellofemoral compartment spacing (arrowheads)
Lateral tibial plateau fracture
The fracture fragment is displaced and depressed from its normal position
Tibial plateau fracture - Lateral
No visible fracture line
Depressed tibial plateau contour (arrow)
Lipohaemarthrosis (fat and blood in the joint)
Patellar fracture - Lateral
Patellar dislocation - Skyline view
The patella is grossly displaced
Knee - Fabella
A fabella is a normal sesamoid bone of the lateral head of gastrocnemius tendon - not to be mistaken for a fracture or loose body
Bipartite patella
The patella is bipartite (in 2 parts) - a common normal variant
Note: Injury to the interface of the 2 components is possible which may be symptomatic
Tibial and fibular fracture
Comminuted fractures of the tibial and fibular shafts with medial displacement and posterior angulation
Tibial stress fracture
Periosteal stress reaction are signs of stress injury (often not present on the initial X-ray)
History of chronic pain worsened by activity
Toddler’s fracture
Fine spiral line through the tibial shaft
This toddler presented with refusal to weight-bear
Ankle anatomy - Normal AP ‘mortise’
The weight-bearing portion is formed by the tibial plafond and the talar dome
The joint extends into the ‘lateral gutter’ (1) and the ‘medial gutter’ (2)
The joint is evenly spaced throughout
Ankle anatomy - Normal Lateral
Carefully following the bone contour of the tibia and fibula shows the inferior edge of the medial and lateral malleoli
Draw where the ligaments would go
Lateral malleolus fracture - AP
Soft tissue swelling laterally (asterisks)
Transverse fracture of fibular tip (Weber A)
The ankle joint remains aligned normally
Describe weber classification
Weber fracture classification
Weber A = Distal to ankle joint (this case)
Weber B = At level of ankle joint
Weber C = Proximal to ankle joint
Bimalleolar fractures - AP
Transverse medial malleolus fracture
Lateral malleolus fracture - at level of ankle joint (Weber B)
Joint widened medially due to lateral displacement of the talus
Trimalleolar fracture - AP and Lateral
1 - Medial malleolus fracture
2 - Lateral malleolus fracture - proximal to the ankle and extending up the fibula (Weber C fracture)
3 - Posterior malleolus fracture
The joint is unstable and widened anteriorly (arrowheads) and at the distal tibiofibular syndesmosis (asterisk)
The talus is displaced posteriorly and laterally along with the medial and lateral malleolus bone fragments
Maisonneuve fracture - Ankle AP
1 - Disruption of the medial ankle joint with small bone avulsion
2 - Disruption of the distal tibio-fibular syndesmosis
No fibular fracture is visible at the ankle raising the suspicion of a proximal fibular fracture
Maisonneuve fracture - AP proximal tibia-fibula
Spiral fracture of the proximal fibula
Osteochondral fracture
Loss of the normal talar dome cortex contour due to an osteochondral fracture
Normal calcaneus - Lateral
Bohler’s angle is normal (39° in this case)
Normal calcaneus - Axial
The cortex of the calcaneus is intact
Calcaneal fracture - Lateral view
Flattening of Bohler’s angle (18° in this case)
Depression of the articular surface of the posterior subtalar joint (red line) from its normal position (green line)
Fracture lines can be seen passing through the calcaneus
Calcaneal fracture - Axial view
Loss of smooth cortical edge (orange line)
Normal foot X-ray anatomy - DP and Oblique views
Hindfoot = Calcaneus + Talus
Midfoot = Navicular + Cuboid + Cuneiforms
Forefoot = Metatarsals + Phalanges
1 = Hind-midfoot junction
2 = Mid-forefoot junction = Tarsometatarsal joints (TMTJs)
Normal Foot X-ray anatomy - DP and Oblique views
Metatarsals and phalanges of the toes are numbered 1 to 5
1 = Big toe
5 = Little toe
MC = Medial Cuneiform
IC = Intermediate Cuneiform
LC = Lateral Cuneiform
Normal Forefoot X-ray anatomy - Joints
MTPJ = Metatarsophalangeal Joints
IPJ = Interphalangeal Joint (of big toe only)
PIPJ = Proximal Interphalangeal Joints
DIPJ = Distal Interphalangeal Joints
Note the medial side sesamoid is ‘bipartite’ (in 2 parts) - this is a common normal variant - not a fracture
normal Forefoot ligament anatomy - Normal
DP - Normal alignment of the 2nd Metatarsal with the Intermediate Cuneiform
Oblique - Normal alignment of the 3rd Metatarsal with the Lateral Cuneiform
Position of the Lisfranc Ligament shown
Lisfranc injury - DP
Second metatarsal displaced from the intermediate cuneiform
No fracture is visible but this is a severe injury which is debilitating if untreated
Note: Lisfranc ligament injury can be subtle and does not always result in displacement - If there is a clinically suspected ligament injury then clinical and radiological follow-up must be arranged
Metatarsal shaft fracture
Oblique fracture of the 5th Metatarsal shaft
Fracture more clearly visible on the oblique image
5th metatarsal base fracture
The fracture line passes transversely across the bone
A normal unfused 5th metatarsal base apophysis is aligned more longitudinally along the bone
Metatarsal stress fracture
Subtle periosteal stress reaction of the 2nd metatarsal
History of chronic pain worsened by activity
Note: Stress fractures are not always visible on the initial X-ray - if suspected repeat X-ray or MRI may be required
Normal skull - Lateral
Anatomically the skull has inner and outer surfaces or ‘tables’
Skull X-rays show the course of vessels which indent the inner table
These vascular indentations branch and taper - whereas fractures do not usually branch or taper
Normal skull - AP
Sutures have a saw-tooth appearance which distinguishes them from fractures which form smooth lines
Skull fractures - AP
The black lines represent skull fractures
These lines are too smooth to be sutures and do not branch like the vascular markings of the skull
Sphenoid air-fluid level
No fracture is visible
The air-fluid level seen in the sphenoid sinus is due to haemorrhage or CSF leakage due to basal skull fracture
The other paranasal sinuses also contain blood due to facial bone injury
Skull - Depressed fracture
Displaced or depressed skull fractures may result in overlapping bone which causes white lines of increased density
Note: The sphenoid sinus is clear - however this does not exclude a basal skull fracture
Occipito-Mental (OM) view - Normal
This view is acquired with the patient looking slightly upwards
Each zygoma and zygomatic arch resembles the head and trunk of an elephant
The blacker areas are the orbits and paranasal sinuses - frontal, nasal/ethmoid, and maxillary
The frontal sinuses are highly variable in appearance
Occipito-Mental (OM30) view - Normal
This view is acquired at 30º from horizontal with the patient in the same position as for the OM view
Each infra-orbital canal is part of the floor of the orbit - these carry the maxillary division of the trigeminal nerve which can be injured as the result of fracture
Note that each maxillary antrum is clear (black)
Other visible structures include the mandible and the odontoid peg
Isolated zygomatic arch fracture
Disruption of the middle McGrigor-Campbell line is due to a comminuted fracture of the right zygomatic arch
Following the upper and lower lines shows no fracture
‘Tripod’ fracture
1 - The zygoma (asterisk) is separated from the frontal bone at the zygomatico-frontal suture
2 - Comminuted fracture of the zygomatic arch
3 - Orbital floor fracture
4 - Breach of the lateral wall of the maxillary antrum
Maxillary antrum fluid level
A fluid level of blood seen in the maxillary antrum may be the only obvious sign of fracture
‘Tripod’ fracture
A - Widened zygomatico-frontal suture
B - Zygomatic arch fracture
C - Orbital floor fracture
D - Lateral maxillary antrum wall fracture
Note
The zygomatico-frontal suture (A) has a variable normal appearance
Widening of the suture - if seen alone - does not indicate a fracture
Orbital ‘blowout’ fracture - Teardrop sign
On the left a ‘teardrop’ of soft tissue has herniated from the orbit into the maxillary antrum
Orbital emphysema - ‘Eyebrow’ sign
Fractures are visible of the lateral wall of the maxillary antrum and of the orbital floor
Air has leaked into the orbit and is seen as an area of comparative low density - the ‘eyebrow’ sign
There is also increased soft tissue density due to swelling, and increased density of the maxillary antrum due to blood
Fracture v normal suture
The eye is drawn to the dark irregular line passing across the orbit which is the normal coronal suture
A systematic approach reveals a tripod injury with a large fracture of the orbital floor
Normal mandible - Orthopantomogram (OPG)
Follow the cortical edge all the way around the mandible
Check the temporomandibular joints
Asterisks = Inferior alveolar canal - the course of the inferior alveolar nerve
Normal mandible - Mandibular view
Follow the cortical edge all the way around the mandible
Mandible fracture - OPG
(Same patient as image below)
A fracture of the left mandible body is easy to see
On the right the cortical outline is difficult to follow at the base of the condyle (?) - but no second fracture is readily seen
Mandible fracture - Mandibular view
(Same patient as image above)
On this view the right condylar fracture is more easily seen
C spine systematic approach
C-spine - Systematic approach
Coverage - Adequate?
Alignment - Anterior/Posterior/Spinolaminar
Bones - Cortical outline/Vertebral body height
Spacing - Discs/Spinous processes
Soft tissues - Pre-vertebral
Edge of image
Normal Lateral 1
Coverage - All vertebrae are visible from the skull base to the top of T2 (T1 is considered adequate)
- If T1 is not visible then a repeat image with the patient’s shoulders lowered or a ‘swimmer’s’ view may be necessary
Alignment - Check the Anterior line (the line of the anterior longitudinal ligament), the Posterior line (the line of the posterior longitudinal ligament), and the Spinolaminar line (the line formed by the anterior edge of the spinous processes - extends from inner edge of skull)
- GREEN = Anterior line
- ORANGE = Posterior line
- RED = Spinolaminar line
Bone - Trace the cortical outline of all the bones to check for fractures
Note: The spinal cord (not visible) lies between the posterior and spinolaminar lines
Disc spaces - The vertebral bodies are spaced apart by the intervertebral discs - not directly visible with X-rays. These spaces should be approximately equal in height
Pre-vertebral soft tissue - Some fractures cause widening of the pre-vertebral soft tissue due to pre-vertebral haematoma
- Normal pre-vertebral soft tissue (asterisks) - narrow down to C4 and wider below
- Above C4 ≤ 1/3rd vertebral body width
- Below C4 ≤ 100% vertebral body width
Note: Not all C-spine fractures are accompanied by pre-vertebral haematoma - lack of pre-vertebral soft tissue thickening should NOT be taken as reassuring
Edge of image - Check other visible structures
Disc spaces - The vertebral bodies are spaced apart by the intervertebral discs - not directly visible with X-rays. These spaces should be approximately equal in height
Pre-vertebral soft tissue - Some fractures cause widening of the pre-vertebral soft tissue due to pre-vertebral haematoma
- Normal pre-vertebral soft tissue (asterisks) - narrow down to C4 and wider below
- Above C4 ≤ 1/3rd vertebral body width
- Below C4 ≤ 100% vertebral body width
Note: Not all C-spine fractures are accompanied by pre-vertebral haematoma - lack of pre-vertebral soft tissue thickening should NOT be taken as reassuring
Edge of image - Check other visible structures
C-spine normal anatomy - Lateral (detail)
Bone - The cortical outline is not always well defined but forcing your eye around the edge of all the bones will help you identify fractures
C2 Bone Ring - At C2 (Axis) the lateral masses viewed side on form a ring of corticated bone (red ring)
This ring is not complete in all subjects and may appear as a double ring
A fracture is sometimes seen as a step in the ring outline
C-spine systematic approach - Normal AP
Coverage - The AP view should cover the whole C-spine and the upper thoracic spine
Alignment - The lateral edges of the C-spine are aligned (red lines )
Bone - Fractures are often less clearly visible on this view than on the lateral
Spacing - The spinous processes (orange) are in a straight line and spaced approximately evenly
Soft tissues - Check for surgical emphysema
Edges of image - Check for injury to the upper ribs and the lung apices for pneumothorax
C-spine normal anatomy - Open mouth view
This view is considered adequate if it shows the alignment of the lateral processes of C1 and C2 (red circles)
The distance between the peg and the lateral masses of C1 (asterisks) should be equal on each side
Note: In this image the odontoid peg is fully visible which is not often achievable in the context of trauma due to difficulty in patient positioning
Open mouth view - Rotated
The distance between the peg and the lateral processes is not equal - compare A (right) with B (left)
This is because when the image was acquired the patient’s head was rotated to one side
Alignment of the lateral processes can still be assessed and is seen to be normal
C-spine normal anatomy - ‘ Swimmer’s’ view
Oblique image with the humeral heads projected away from the C-spine
The cervico-thoracic junction can be seen
Check alignment by carefully matching the corners of each adjacent vertebral body - anteriorly and posteriorly
C1 ‘Jefferson’ fracture - Open mouth view
The space between the odontoid peg of C2 and the lateral masses of C1 is widened on both sides (arrows)
The lateral masses of C1 are both laterally displaced and no longer align with the lateral masses of C2 (red rings)
Injury to C1(atlas) results in loss of integrity of its ring structure. The ring expands and loses alignment with the adjacent occipital bone above, and C2 below. This is most readily appreciated on the open mouth view which shows that the lateral masses of C1 no longer align with the lateral masses of C2, and that the spaces between the peg and the C1 lateral masses are widened.
C2 odontoid peg fracture - Lateral view
The C2 bone ‘ring’ is incomplete due to a fracture
The odontoid peg is displaced posteriorly
C2 odontoid peg fracture - Open mouth view
Displaced fracture of the odontoid peg
It is uncommon to see such an obvious fracture on the open mouth view - many fractures of the odontoid peg are more readily seen on the lateral view
C2 ‘hangman’ fracture - Lateral view
Loss of alignment at C2/C3 with anterior displacement of C2 (large arrow)
Following the cortical outline of C2 (white line) reveals discontinuity due to a fracture
The so called ‘hangman’ fracture results from a high force hyperextension injury. The fracture involves the pedicles of C2 and often results in anterior displacement of the body and peg of C2.
‘Extension teardrop’ fracture - Lateral view
A fracture fragment is seen at the anterior/inferior corner of C2 resembling a ‘teardrop’
Hyperextension may result in avulsion of the anterior corner of a vertebral body - most commonly C2. The anterior longitudinal ligament remains attached to the bone fragment which is separated from the vertebral body.
‘Flexion teardrop’ fracture - Lateral view
Following the outline of the vertebral bodies shows an anterior - inferior C6 vertebral corner ‘teardrop’ fracture fragment
The facet joint of C6/C7 is widened - compare with level above
This fracture may occur at any level between C3 and C7. It is a highly unstable injury with a high incidence of associated spinal cord injury.
Bilateral perched facets - Lateral view
(Same patient as image below)
Loss of alignment of all three lines at C5/C6 with ‘perching’ of the C5 facet on the C6 facet (ring)
No fracture is visible
The pre-vertebral soft tissue is widened due to a haematoma
Note
The spinal canal lies between the posterior (Orange) and spinolaminar (Red) lines
Derangement of the spinal canal due to this injury results in a high incidence of spinal cord injury
Bilateral perched facets - AP view
There is widening of space between the C5 and C6 spinous processes (SP) with loss of normal alignment
Again no fracture is demonstrated
Pre-vertebral soft tissue
At the level of C3 the pre-vertebral soft tissue is thickened - ( >1/3rd the width of the vertebral body)
This soft tissue swelling is the only visible sign of injury
CT showed a fracture at C4 not visible on the plain X-ray
Note
Not all C-spine fractures are accompanied by pre-vertebral haematoma
Lack of pre-vertebral soft tissue thickening should NOT be taken as reassuring
Spinous process fracture
A large bone fragment is widely displaced from the C7 spinous process
Isolated fractures of the spinous processes are often difficult to identify, especially at the cervico-thoracic junction where they may be obscured by overlying soft tissues. A specific check is necessary of the cortical outline of each spinous process.These avulsion injuries are traditionally known as ‘clay-shoveller’s’ fractures due to the mechanism of repeated forceful flexion associated with shovelling.
Sternum - Normal - Lateral
Note the normal sternomanubrial joint which should not be mistaken for a fracture
Sternal fracture - Lateral
A step in the cortex of the sternum indicates a fracture
Rib fractures - Chest X-ray (detail)
Multiple displaced lower left rib fractures are visible
Subtle rib fracture - Shoulder X-ray
The clavicle fracture is obvious
A subtle rib fracture is also seen
Note: Always check for a second injury
Unexpected rib fracture - Shoulder X-ray
This patient presented with no clear history of trauma and complained of shoulder pain
Shoulder examination was unremarkable
Rib fractures with haemothorax - Chest X-ray
Multiple rib fractures are accompanied by a small pleural effusion - likely a haemothorax
Rib fracture with pneumothorax - Chest X-ray
A minimally displaced rib fracture is visible
This fracture is complicated by a haemothorax and a pneumothorax with surgical emphysema
Systematic approach to thoracolumbar spine
Coverage - The whole spine is visible on both views
Alignment - Follow the corners of the vertebral bodies from one level to the next
Bones - The vertebral bodies should gradually increase in size from top to bottom
Spacing - Disc spaces gradually increase from superior to inferior - Note: Due to magnification and spine curvature the vertebral bodies and discs at the edges of the image can appear larger than those in the centre of the image
Soft tissues - Check the paravertebral line (see AP image below)
Edge of image - Check the other structures visible
T-spine normal anatomy - Lateral (detail)
Alignment - Vertebral body alignment is assessed by carefully matching the anterior and posterior corners of the vertebral bodies with the adjacent vertebra
Bones - Gradual increase in vertebral body height from superior to inferior
Spacing - Disc spaces gradually increase in height from superior to inferior
VB = Vertebral body
P = Pedicle
SP = Spinous process (ribs overlying)
F = Foramen - spinal nerve root exit
T-spine normal anatomy - AP (detail)
Alignment - The vertebral bodies and spinous processes (SP) are aligned
Bones - The vertebral bodies and pedicles are intact
Other visible bony structures include the transverse processes (TP), ribs, and the costovertebral and costotransverse joints
Spacing - Each disc space is of equal height when comparing left with right. The pedicles gradually become wider apart from superior to inferior
Soft tissue - Note the normal paravertebral soft tissue which forms a straight line on the left - distinct from the aorta
L-spine systematic approach - Lateral
Coverage - The whole L-spine should be visible on both views
Alignment - Follow the corners of the vertebral bodies from one level to the next (dotted lines)
Bones - Follow the cortical outline of each bone
Spacing - Disc spaces gradually increase in height from superior to inferior - Note: The L5/S1 space is normally slightly narrower than L4/L5
L-spine normal anatomy - Lateral (detail)
Check the cortical outline of each vertebra
The facet joints comprise the inferior and superior articular processes of each adjacent level
The pars interarticularis literally means ‘part between the joints’
P = Pedicle
SP = Spinous process
L-spine systematic approach - Normal AP
Alignment - The vertebral bodies and spinous processes are aligned
Bones - The vertebral bodies and pedicles are intact
Spacing - Gradually increasing disc height from superior to inferior. The pedicles gradually become wider apart from superior to inferior - Note: The lower discs are angled away from the viewer and so are less easily assessed on this view
L-spine normal anatomy - AP (detail)
Check carefully for pedicle integrity and transverse process fractures
What is the 3 column model + associated spinal injuries?
L spine - normal
Three column model - Anatomy
Anterior column = Anterior half of the vertebral bodies and soft tissues
Middle column = Posterior half of the vertebral bodies and soft tissues
Posterior column = Posterior elements and soft soft tissues
Basic thoracolumbar spine injury classification
1 column - Anterior compression (or isolated spinous process injuries)
2 column - Burst injuries
3 column - Flexion-distraction ‘Chance-type’ injuries
Anterior compression injury - L-spine - Lateral
(Same patient as image below)
A poorly defined dense (white) fracture line is visible with a detached fracture fragment (asterisk)
L1 has lost height anteriorly and there is disruption of the anterior column only
Anterior compression injury is a common fracture pattern which results from traumatic hyper-flexion with compression. Although considered ‘stable’ the greater the loss of height anteriorly the greater the risk of middle column involvement. X-ray may underestimate the extent of injury and so if there has been high risk injury or other suspicion of instability then CT should be considered.
Anterior compression injury - L-spine - AP
(Same patient as image above)
Loss of vertebral body height can be seen but the fracture is not visible on this view
Thoracolumbar ‘Burst’ fracture - Lateral
Both the anterior and middle columns are disrupted
Injury has resulted in increased kyphosis
A large vertebral body fragment is displaced anteriorly
‘Burst’ fractures result from high force vertical compression trauma. Posterior displacement of vertebral body fracture fragments into the spinal canal leads to a high risk of spinal cord or nerve root damage.
Thoracolumbar ‘Burst’ fracture - AP
(Same patient as image above)
The T12 vertebral body has lost height and the adjacent rib is fractured
The interpedicular width should increase gradually from superior to inferior (white dotted lines)
At the level of the fracture there is sudden widening of the interpedicular width - Note: This sign is not always visible in burst fractures
The normal paravertebral soft tissues (asterisks) is widened by a paraspinal haematoma at the level of the fracture
Flexion-distraction / ‘Chance’ fracture - Lateral
All three columns are disrupted
A = Widened spinous processes (SP) indicating disruption of the interspinous ligaments at the level of the fracture
B = Normal interspinous distance
Flexion-distraction injuries are associated with high force deceleration injuries and are most common at the thoracolumbar junction. Also known as ‘Chance-type’ fractures (after the radiologist who first described them) these injuries are unstable and carry a high risk of neurological deficit and abdominal organ injury.The ‘fracture’ line may pass through the disc rather than the vertebral body, and so there may not be visible bone injury of the anterior column.
Flexion-distraction / ‘Chance’ fracture - AP
The interspinous distance is increased at the level of the fracture
In this case the pedicles and transverse processes have been split horizontally
Thoracic spine - ‘Wedge’ compression fracture
Note the low density (blackness) of the vertebral bodies
The vertebral body has lost height anteriorly
Kyphosis is increased
Lumbar spine - Biconcave fracture
Note the low density (blackness) of the vertebral bodies
Compression injuries of both the superior and inferior endplates of the vertebral body have resulted in a biconcave appearance
The vertebral body has also lost height anteriorly - compare to level below (superimposed dotted line)
Transverse process fracture - Lumbar spine AP
Multiple fractures of the transverse processes are seen on one side
Transverse process fractures are often not visible with X-ray - (only seen on CT), and are often associated with other fractures - so if seen are a prompt to recheck all X-ray images available and consider further imaging. Transverse process fractures are also associated with injury to the kidneys.
Spinous process fracture - Lumbar spine - Lateral
Only 1 column is visibly injured but further imaging should be considered
Pelvis anatomy - Normal AP
The 2 hemi-pelvis bones and the sacrum form a bone ring bound posteriorly by the sacroiliac joints and anteriorly by the pubic symphysis
Each obturator foramen is also formed by a ring of bone
Hemi-pelvis anatomy - Normal AP
Each hemi-pelvis bone comprises 3 bones - the ilium (white), pubis (orange) and ischium (blue)
The 3 bones fuse to form the acetabulum - the pelvic portion of the hip joint
ASIS = Anterior Superior Iliac Spine = attachment site for sartorius muscle
AIIS = Anterior Inferior Iliac Spine = attachment site for rectus femoris muscle
Pubic ramus fracture
The obturator ring is incomplete on the right
A fracture passes through the superior and inferior pubic rami
Compare with the normal left side
Acetabular fracture
A tiny step in the cortical edge of the pelvic ring reveals a fracture which passes into the acetabulum
The fracture passes to the obturator ring and then through the inferior pubic ramus
Pelvis diastasis
High force injury to the bony pelvis may result in “diastasis” (separation) at the pubic symphysis or a sacroiliac joint.
Both the pubic symphysis and the right sacroiliac joint are widened
There is complete separation of the right hemi-pelvis from the axial skeleton
ASIS avulsion fracture
A small fragment of bone has detached from the pelvis
All or part of the sartorius tendon origin will be attached to the bone fragment
Note the normal appearance of the unfused iliac crest apophysis in this male teenager
Pelvis anatomy - Sacrum - Normal AP
The sacrum and the iliac bones overlap to form the sacroiliac joints
The arcuate lines of the sacrum are the roofs of the sacral exit foramina which carry the sacral nerve roots
Sacral fracture- AP pelvis
Loss of the smooth arcuate lines is a sign of sacral fracture
MRI knee
MRI allows detailed analysis of musculoskeletal body parts such as the knee
Bone marrow is clearly visible – in the femur and tibia in this case
Bone cortex is less clearly visible on MRI and is often better seen with CT scans or plain X-rays
MRI arthrogram – shoulder
Fluid containing gadolinium has been injected into the shoulder joint revealing displacement of the anterior glenoid labrum in this patient with recurrent shoulder dislocation
G = Glenoid of scapula
H = Head of humerus
Gadolinium can be injected directly into a body part. For example, a joint can be injected to help visualise joint structures (MRI arthrogram).
Bilateral hilar enlargement
Both hila are larger and denser than normal
Clinical information = Joint pain, Erythema nodosum
Diagnosis
Sarcoidosis
Differential
Lymphoma, metastatic disease or infection may occasionally look similar
Pulmonary arterial hypertension may also cause bilateral symmetrical hilar enlargement
Pneumothorax
Visible pleural edge (blue line)
Lung markings not visible beyond this edge
Clinical information
Fall from height - trauma to chest
Diagnosis
Left pneumothorax due to a rib fracture (arrowhead)
The trachea and mediastinal structures are not displaced so there is no ‘tension’
Multiple acute rib fractures
Blunt trauma to chest wall
Mobile supine chest X-ray
Multiple fractures of the 4th right rib (highlighted)
Other visible fractures of 3rd, 5th, 6th and 7th right ribs (arrowheads)
Raised right hemidiaphragm due to reduced ventilation secondary to pain
Increased density of the right lower zone due to lung contusion
Generalised increased density on the right likely due to a haemothorax
Note: A pneumothorax cannot be excluded on a supine X-ray
elbow dislocation
ulnar styloid #
UCL thumb avulsion #
posterior hip dislocation
Legg Calve Perthe’s
cam deformity
ACL tear
Baker’s cyst
Patella dislocation
Knee dislocation
Tibial plafond #
Haglunds deformity
pulmonary contusion
herpes gladiatorum
bullous impetigo
tinea pedis
tinea corporis
