upper limbs

Question 1

3 rules when assessing radiographs

Answer 1

always evaluate both views

adopt a systemic checking process for each projection

compare with previous radiographs

Question 2

description of fractures

Answer 2

identify fractured bone
state
- site
- closed or open
- fragments
- direction of fracture
- articular surface involvement
- position of the two major fragments
- angulation
- rotational deformity

Question 3

Salter-Harris fractures in paeds

Answer 3

Type 1 - ‘S’eparation: restricted to the growth plate
Type 2 - ‘A’bove
Type 3 - ‘L’ower
Type 4 - ‘T’hrough
Type 5 - ‘Er’asure / Impacted

Type 2-4 involves the growth plate and the adjacent metaphysis and/or epiphysis

Question 4

Fractures in paeds

Answer 4

• torus/buckle: a bulge in the cortex
• bowing: associated bend in the bone shaft
• greenstick: bending of the shaft with a fracture on the convex surface
• salter-harris: involving the growth plate

Question 5

type of fractures in general patients

Answer 5

transverse
linear
oblique nondisplaced
oblique displaced
spiral
greenstick
comminuted

Question 6

type of bone and joint injuries

Answer 6

osteochondral fractures
- fracture of part of a joint surface

avulsion fractures
- small chunk of bone attached to a tendon or ligament gets pulled away from the main part of the bone

stress fracture
- occur when repeated forces on the bones are abnormally high

pathological fractures
- usually caused by a focal lesion

Question 7

x-ray appearances of fractures

Answer 7

• radiolucent line
• alignment: undisplaced or displaced
• bony margins: step or discontinuity of cortical margins
• impacted: band of increased bone density
• swelling of soft tissue

Question 8

skier’s thumb

Answer 8

• usually accompanied with torn medial collateral ligament
• at times, may accompany an avulsion of base of proximal phalanx

Question 9

Bennett’s fracture

Answer 9

involves base of 1st metacarpal

Question 10

rolando’s fracture

Answer 10

comminuted intra-articular fracture of the base of the 1st metacarpal

Question 11

boxer’s fracture

Answer 11

fracture of the neck of the 5th metacarpal

Question 12

measurements to assess distal radius

Answer 12

1. radial inclination = 23deg
2. radial height = 12mm
3. ulnar variance = 0.9mm
4. tilt volar = 11-12deg

Question 13

common causes of positive ulnar variance

Answer 13

• scapholunate instability
• ulnar impaction syndrome
• triangular fibrocartilage tears

Question 14

cause of negative ulnar variance

Answer 14

kienbock’s disease (osteonecrosis of lunate bone)

Question 15

findings suggestive of distal radius fracture

Answer 15

• radial inclination change > 5deg
• radial shortening > 5mm
• ulnar variance (-4.2mm to +2.3mm)
• volar tilt with dorsal angulation of > 5deg

Question 16

terry-thomas sign

Answer 16

increased distance between the scaphoid and the lunate (scapholunate space) on PA wrist associated with scapholunate dissociation

Question 17

colles fracture

Answer 17

• dinner fork deformity
• extra-articular
• dorsal displacement of distal fragment

Question 18

smith fracture

Answer 18

• extra-articular
• ventral displacement of distal fragment

Question 19

barton’s fracture

Answer 19

• involved the dorsal cortex of distal radius and articular surface
• intra-articular

Question 20

reverse barton’s fracture

Answer 20

• involves the anterior cortex of distal radius and articular surface
• intra-articular

Question 21

galeazzi fracture

Answer 21

• commonly result from FOOSH with extended wrist and hyperpronated forearm
• radial shaft fracture
• separation of distal radio-ulna joint

Question 22

Monteggia type fractures

Answer 22

• displaced fracture of the ulna with shortening
• loss of alignment of the radiocapitellar line due to dislocation of the radial head

Question 23

order of elbow ossification centre development

Answer 23

Capitulum
Radial head
Internal epicondyle (medial)
Trochlea
Olecranon
Lateral epicondyle (External)

6 months to 12 years

Question 24

elbow fat pad indication

Answer 24

• displaced anterior fat pad = highly likely a fracture
• displaced posterior fat pad = suspected fracture
• fat pads not displaced = occasionally a fracture

Question 25

normal elbow alignment

Answer 25

radio-capitellar line – both AP and lateral views
- line drawn along the mid radius should pass through the capitellum

anterior humeral line – lateral view
- line drawn along the anterior humeral margin should cut through 1/3 of the capitellum

Question 26

normal shoulder growth in children

Answer 26

head - 1 year
greater tubercle - 3 years
lesser tubercle - 5 years

Question 27

most common type of shoulder dislocation

Answer 27

anterior dislocation
- represent 95-98% of all glenohumeral dislocation

posterior dislocation of shoulder joint
- 2-5%

subluxations and dislocations of acromio-clavicular joints

Question 28

anterior dislocations of shoulders mechanism of injury

Answer 28

caused by FOOSH or fall onto shoulder in abduction, external rotation and extension

humeral head comes to lie anterior, medial and somewhat inferior to its normal location and glenoid fossa

associated with
- bankart lesion
- hill-sacs lesion

Question 29

xray view of anterior dislocated shoulder

Answer 29

• humeral head and glenoid surfaces not aligned
• humeral head lies below the coracoid
• humeral head is displaced medially

Question 30

xray view of posteriorly dislocated shoulder

Answer 30

humeral head is forced posteriorly in internal rotation while the arm is abducted

can be cause by muscle contraction from electric shock/ seizure or axial load while arm is internally rotated, adducted, flexed

“lightbulb sign” on AP view as humerus is internally rotated

Question 31

systematic approach in MSK

Answer 31

Alignment - check for change in position which may suggest fracture or dislocation

Bone cortices (any breach) and texture (change in density or trabecular pattern)

Cartilage - check for joint space, formation of osteophytes

Soft tissues - swelling