ACJ INJURIES: fall on shoulder with arm adducted
1. Sprained ACJ , no disp
2. Torn capsule and subluxation
but coracoclavicular ligaments
3. Dislocation with torn CCL
4. Clavicle displaced post
5. Very markedly upwards
6. Inferiorly beneath the coracoid
• Normal AC joint width is 3 – 5
mm or no
>3mm difference in two sides.
Type 1 sprain
Type 2 rupture of AC lig and
joint capsule with widening
Type 3 same as type 2 with
coracoclavicular lig disruption
Grade III AC joint injury: Coracoclavicular distance is > than 1.3 cm on AP view.
SHOULDER DISLOCATION : ACUTE
Severe pain, supports arm with opposite arm, lateral outline of shoulder
flattenned, examine for nerve and vessel injury before reduction
Over 95% of glenohumeral dislocations
Hill-Sachs deformity: compression fracture of posterolateral aspect of the humeral head.
Bankart’s lesion: fracture of the anterior lip of the glenoid.
Complication: fracture of greater tuberosity of the humerus
Pseudosubluxation: Haemorrhagic effusion may push head of humerus inferiorly, but not medially,
which eventually disappears within a week or two.
Arm held in medial rotation
and locked in that position
front of shoulder looks flat with
Due to indirect force causing
marked internal rotation and
adduction: convulsion or
electric shock causing
1. fall on flexed adducted arm
2. direct blow to front of
POSTERIOR DISLOCATION: < 5% of shoulder dislocation
50% overlooked on initial radiographs
AP view : Light Bulb appearance of internally rotated humerus
Y view: Centre of humerus lies post to limbs of Y
Axial (armpit view) and aapical oblique view: golf ball lies post to tee
AP view: Head of humerus changes from a “club headed walking stick” to “light bulb”
Pitfall: arm held in internal rotation
Y view: Humeral head lies behind the center of the glenoid.
Positive RIM sign on AP view in Post Shoulder dislocation:
Rings true in 66% of shoulder dislocation patients.
Distance between the medial border of the humeral head and the anterior glenoid rim is > 6 mm
Axial view for post Shoulder dislocation: Golf ball is off the tee.
Elbow fractures: a fool proof guide.
No one is immune and no favourites!!
Olympian snow boarder Mathew Morrison from Canada
1. Appreciate the
“hourglass” or “figure of
eight” : the hallmark of
a true lateral radiograph
Not true lateral
2. Evaluate anterior fat pad
3. Posterior fat pad evaluation : Always abnormal
4. Evaluate the anterior humeral line and radiocapitellar line
Abnormal Ant humeral line: in a supracondylar fracture
7. Evaluate the bony
cortex of the distal
8. Last but not least:
Evaluate the olecranon
and proximal ulna.
MONTEGGIA FRACTURE DISLOCATION
Fracture of the mid shaft of the ulna with dislocation of the proximal radioulnar joint, FOOSH
with forcible pronation of forearm, key is to restore length of fractured ulna.
Cf GALLEAZZI fracture of the radius with dislocation of the distal radio-ulna joint. (More
common, prominence/tenderness over lower ulna, ballotting distal ulna “piano key sign”;
look for ulnar nerve injury
AVULSED MEDIAL EPICONDYLE
(Little leaguer’s elbow)
If trochlear centre is seen; there must be an ossified
internal epicondyle visible somewhere on the radiograph.
When in doubt: Obtain radiographs of the unijured side for
• OSSIFICATION CENTRE IN THE
• Radial head
• Internal epicondyle
• Lateral/External epicondyle
Remember “I before T”
Key points of evaluation on Normal lateral view:
1. The 3 Cs
2. Capitolunate angle is less than 10 to 20 degrees.
3. Scapholunate angle is less than 60 degrees.
4. Radial volar tilt of 10 to 15 degrees.
Linked carpal segments collapse.
DISI: Lunate is torn from the scaphoid and tilted backwards
VISI: Lunate is torn from the triquetrum and turns towards the palm, and capitate assumes a
complimentary dorsal tilt.
There may be a flake fracture off back of carpal bone (triquetrum).
1. Lunate tilts dorsal and slides palmar increasing the capitolunate angle. CL>20
2. Scaphoid tilts more palmar and increases the scapholunate angle. SL > 60
3. The axes of radius lunate and capitate takes on a zigzag pattern.
1. Lunate tilts palmar increasing the capitolunate angle. CL > 20
2. The scapholunate angle is maintained. SL < 60
3. The axes of radius lunate and capitate takes on a zigzag pattern, in the opposite direction.
Described by Abraham Colles in 1814.
EXTRARTICULAR (does not extend into joint space)
transverse fracture of the radius just above wrist
(cortico-cancellous junction) with dorsal displacement ,
radial tilt and shortening of distal fragment
: dinner fork deformity
Ulnar styloid process is often fractured.
Elderly lady –FOOSH- post menopausal osteoporosis.
Closed reduction by extension of the wrist and pressing
the distal fragment into place by pressing on the
dorsum while manipulating the wrist into flexion ulnar
deviation and pronation.
SMITH’S FRACTURE : reversed Colles
Dubliner like Colles described 20 yrs
Fall on the back of the hand.
Garden spade deformity.
Fracture through the distal radial
metaphyses where the distal fragment
is displaced and tilted anteriorly.
Traction and extension of the wrist for
Intra-articular fracture of the dorsal margin of the distal radius.
Extends into the radio-carpal joint.
Hutchison or Chauffer’s fracture
Intra-articular fracture of the radial styloid process ,
Begins at the junction of the lunate and scaphoid fossa on the articular surface of the radius and extends
Chauffer’s : Injury occurred from a direct blow to the wrist from backfiring of the starting crank of an
ROLANDO FRACTURE Communited
Fracture through base of thumb.
Difficult to reduce.
Prognosis is worse than Bennetts fracture.
Intra-articular fracture dislocation of the base of first metacarpal.
Small fragment of 1st metacarpal continues to articulate with the trapezium.
Lateral retraction of first metacarpal shaft by abductor pollicis longus.
70% of all carpal injuries
Complicated by delayed union
And non union and avascular necrosis
Blood supply to proximal pole via an intraosseous
branch from the middle pole vessel-the more proximal
the fracture the greater the risk of non union
• Dorsal Avulsion injuries
• Proximal – Triquetral
• Dorsal – Hamate often with associated
fracture dislocation of the fourth
Fall with hand forced into dorsiflexion.
Lunate remains attached to radius and rest of carpus is displaced
Capitate and metacarpals lie behind the line of the radius (DISI pattern)
Most dislocations are peri-lunate.
After perilunate dislocation, usually the hand immediately snaps forward again.
As it does so the lunate is levered out of position to be displaced anteriorly.
At times the scaphoid remains attached to the radius and the force of perilunate dislocation causes it to fracture through
the waist resulting in a trans-scaphoid perilunate dislocation.
BASEBALL OR MALLET FINGER
Injury due to forced flexion of the extended thumb at
the site of insertion of the common extensor tendon
DIP held in flexion
Extensor Tendon anatomy
and Mallet finger
Injury from blunt or sharp trauma
over the distal phalanx and DIPJ.
Laceration or rupture of the
tendon at this level results in 40
degree flexion at the DIPJ.
When it occurs after blunt trauma
it is the called “mallet finger” .
It is the most common tendon
injury in athletes.
Type 1: tendon only rupture
Type 2: with small avulsion fracture
Type 3: greater than 25% of
articular surface involved.
Swan neck deformity
Lateral bands are displaced proximally and dorsally resulting in increased extension forces on
the PIP joint.
Occurs in chronic untreated mallet finger.
Game Keeper’s or skiers thumb
Involves injury to the ulnar collateral ligament at the thumb MCPJ causing instability at that
UCL nearly always separates from the base of the first phalanx of the thumb.
Proximal margin of the adductor pollicis aponeurosis slides distal to insertion of the UCL
and is called a Steners Lesion.
Game keeper’s /Skier’s thumb
Usually ligament alone is torn and radiographs appear normal.
Occasionally bone fragment at base of proximal phalanx may be avulsed.
Stress radiographs may confirm or exclude diagnosis.
CMCJ dislocation :
Examples of Ring and Little finger dislocation at CMCJ.
PA view: Each CMCJ should be well seen and
bones should not overlap.
Always check oblique view to exclude
dislocation/subluxation at CMCJ.
False positive spurious effacement of a joint from
3 Bone rings: Main pelvic ring and smaller
rings formed by pubic and ischial bones
Cartilaginous synchondrosis between ischial
and pubic bones may simulate fracture lines
in children .
One fracture in a bone ring is frequently
associated with a second fracture.#
Width of sacroiliac joints be equal.
Superior surfaces of pubic rami should align.
Maximum width of pubic symphysis be no
more than 5 mm.
Disruption of the smooth curve of the sacral
foramina (arcuate lines) indicates sacral
Compare both acetabuli.
AP compression injury:
Symphysis and sacro-iliac joint diastasis
Young Burgess classification of AP pelvic ring compression injuries.
TYPE 1: < 2.5 cm pubic diastases seen either at the symph or through pubic rami #.
TYPE 2: Anterior diastases exceeds 2.5 cm and in addition diastases is seen at 1 or
both SI joints resulting in incomplete posterior arch disruption and rotational
instability. Posterior ligaments are preserved hence vertical stability is maintained.
TYPE 3: Posterior SI ligaments are disrupted and this leads to rotational and vertical
Windswept injury: Lateral compression of the pelvis
Left lateral compression injury with internal rotation of left hemipelvis and characteristic sacral buckle fracture.
Also external rotation of the right hemipelvis and diastasis of the right SIJ.
Garden classification of subcapital femoral fractures
: on the basis of distortion of the principal medial compressive trabeculae as
seen before reduction on the AP radiograph.
Incomplete subcapital fracture , stable
Complete but non displaced #
Femoral head is abducted, but neck moves such that alignment is maintained.
Stable with good prognosis.
Complete partially displaced subcapital fracture.
Femoral shaft externally rotated.
Femoral head abducted and axially rotated such that superior surface resides anteriorly.
Femoral neck in varus deformity
Complete and fully displaced fracture.
Femur externally rotated and superiorly displaced.
Femoral head completely detached from neck remains in anatomic position relative to acetabulum.
Unstable fracture with poor prognosis.
Ficat and Arlet classification for AVN of the
Stage 0: No radiograpohic findings. Preclinical stage positive with MRI and bone scan.
Stage 1: Slight osteoporosis on plain images. Clinical symptoms but no sclerosis.
Stage 2: Diffuse osteoporosis and sclerosis in area of infarction. Infarcted area is well
delineated due to reactive shell of bone. Spherical shape of femoral head
Stage 3: Crescent sign: radiolucency under subchondral bone represents fracture.
Abnormal contour of femoral head seen. Joint space preserved.
Stage 4: Femoral head collapse, joint space narrowing and subchondral sclerosis.
AO Classification for
Segond Fracture is an indirect sign of ACL tear.
It is an avulsion fracture at the insertion of the lateral collateral band due to internal rotation and varus stress.
In 75 to 100% of the cases there will also be a tear of the ACL.
O’Donoghue’s syndrome or the unhappy triad occurs in contact sports (football)
when the knee is hit from the outside and three key structures are injured.
1. ACL tear.
2. MCL (medial collateral ligament) tear
3. Medial meniscus tear.
Lipohemarthrosis : plain radiograph and CT
Look for intra-articular fracture, especially tibial plateau fracture.
Lipohemarthrosis on MR
From tibial plateau fracture.
Fat fluid level in the suprapatellar bursa.
Tibial Plateau fracture
On AP view, a perpendicular line drawn at the most lateral margin of the femoral condyle should not have more than 5
mm of the lateral margin of the tibial condyle outside it. (Similar rule may be applied for the medial side.)
Infrapatellar ligament rupture
The distance from the tibial tubercle
(on anterior aspect of the tibia) to the
lower pole of the patella should
approximate to the length of the
patella- plus or minus 20 %.
Pellegrini Steida lesion
Soft tissue calcification adjacent to the medial
epicondyle of the femur
> Is not an avulsion fracture
> Represents calcification following a previous old
sprain of the medial collateral ligament.
Ruedi-Allgower classification of pilon fractures.
Pilon : french for pestle
Low impact pilon fracture:
Low energy rotational force
and some axial
compression , with little
soft tissue injury and
High impact pilon fracture:
High energy axial
compression resulting in
extensive soft tissue injury
and severe articular and
Ligaments often avulse fragments
Chaput: antro lateral fragment
Wagstaffe: posterior malleolar
Most common tarsal fracture.
Mechanism : axial load (RTA, fall from height)
Extra-articular (25%) : Avulsion injury of anterior process of bifurcate
ligament, sustentaculum tali or calcaneal tuberosity.
Eg; anteriro process fracture, fatigue fracture from repetitive stress
trauma seen as bone sclerosis
Intra-articular(75%) : involves subtalar or calcaneocuboid joints
Results in flattening of the bone and Bohler’s angle is <30 degress.
Impacted fracture may be evident as sclerotic line or density in the body.
Essex Lopresti classification:
primary fracture line runs obliquely through posterior facet forming two
Secondary fracture line runs either
in the axial plane beneath the facet and exits posteriorly in
tongue type fracture.
or just behind posterior facet in joint depression fracture.
Sanders classification: coronal CT image at level of posterior facet.
Type 1 : Non displaced post facet regardless of number of fragments.
Type 2: One fracture line in post facet (2 fragments)
Type 3: two fracture lines in post facet (3 fragments)
Type 4: three fracture lines in post facet (four + fragments)
BOHLER’S ANGLE: Normal angle is 30 to 40 degrees on a lateral radiograph.
Measured by drawing a line from the posterior aspect of the calcaneum to its highest midpoint
a second line drawn from the highest midpoint to the highest anterior point.
Angle between these lines is measured as shown.
In case of calcaneal fracture with compression Bohler’s angle is flattened (less than 30 degrees)
Types of extra-articular calcaneal avulsion
LIS FRANC FRACTURE DISLOCATION
Lisfranc fracture dislocation
• AP view: Does the medial margin of the base of second
metatarsal align with medial margin of intermediate cuneiform?
• Oblique view: Does the medial margin of the third metatarsal
align with the medial margin of the lateral cuneiform? :: useful in
cases of second metatarsal fracture distal to its base where the
proximal fragment is held in place in the cuneiform mortice but
the distal fragment dislocates laterally with the third fourth and
Types of Lisfranc tarso metatarsal dislocation:
Homolateral :All 5 metatarsals are displaced in the same direction and lateral displacement suggests cuboid fracture.
Isolated: One or two metatarsals are displaced from the others.
Divergent: Metatarsals displaced in a sagittal or coronal plane. May involve intercuneiform area and a navicular fracture.
5THT METATARSAL CONUNDRUMS
Skeletal survey/Bone Scan
Injuries Specific for NAI
Posterior Rib #
3 S’s- Scapular(acromion)