Mid shaft # common : Outer fragment pulled down, Inner fragment
1. Sprained ACJ , no disp
2. Torn capsule and subluxation but coracoclavicular
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
Type 1 sprain
Type 2 rupture of AC lig and
joint capsule with widening
Type 3 same as type 2 with
Severe pain, supports arm with opposite arm, lateral outline of
shoulder flattened, examine for nerve and vessel injury before
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.
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 apical oblique view: golf ball lies post to tee
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
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
(Little leaguer’s elbow)
If trochlear centre is seen; there must be an ossified
internal epicondyle visible somewhere on the
When in doubt: Obtain radiographs of the unijured
CENTRE IN THE
Remember “I before T”
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
: dinner fork deformity
Ulnar styloid process is often fractured.
Elderly lady –FOOSH- post menopausal
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.
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
Traction and extension of the wrist
Intra-articular fracture of the dorsal margin of the distal radius.
Extends into the radio-carpal joint.
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
Chauffer’s : Injury occurred from a direct blow to the wrist from backfiring of the starting crank of an
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
Dorsal Avulsion injuries
Proximal – Triquetral
Dorsal – Hamate often with
associated fracture dislocation of
the fourth metacarpal
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
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
DIP held in flexion
Injury from blunt or sharp
trauma over the distal phalanx
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
It is the most common tendon
injury in athletes.
Type 1: tendon only rupture
Type 2: with small avulsion
Type 3: greater than 25% of
articular surface involved.
Lateral bands are displaced proximally and dorsally resulting in increased extension
forces on the PIP joint.
Occurs in chronic untreated mallet finger.
Involves injury to the ulnar collateral ligament at the thumb MCPJ causing instability
at that joint.
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.
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.
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 abnormal position.
3 Bone rings: Main pelvic ring and
smaller rings formed by pubic and ischial
bones (obturator foramina)
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
Maximum width of pubic symphysis be
no more than 5 mm.
Disruption of the smooth curve of the
sacral foramina (arcuate lines) indicates
Compare both acetabuli.
TYPE 1: < 2.5 cm pubic diastases seen either at the symph or through pubic
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
TYPE 3: Posterior SI ligaments are disrupted and this leads to rotational and
Left lateral compression injury with internal rotation of left hemipelvis and characteristic sacral buckle
Also external rotation of the right hemipelvis and diastasis of the right SIJ.
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.
Stage 0: No radiograpohic findings. Preclinical stage positive with MRI and
Stage 1: Slight osteoporosis on plain images. Clinical symptoms but no
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 maintained.
Stage 3: Crescent sign: radiolucency under subchondral bone represents
Abnormal contour of femoral head seen. Joint space preserved.
Stage 4: Femoral head collapse, joint space narrowing and subchondral
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.
Look for intra-articular fracture, especially tibial plateau fracture.
From tibial plateau fracture.
Fat fluid level in the suprapatellar bursa.
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.)
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 %.
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
Essex Lopresti classification:
primary fracture line runs obliquely through posterior facet forming
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
Sanders classification: coronal CT image at level of posterior
Type 1 : Non displaced post facet regardless of number of
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)
Measured by drawing a line from the posterior aspect of the calcaneum to its highest
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
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 fifth
Homolateral :All 5 metatarsals are displaced in the same direction and lateral displacement suggests cuboid
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
OF FIFTH MT
Injuries Specific for NAI
Posterior Rib #
3 S’s- Scapular(acromion)