Pelvis and Acetabulum

Question 1

Why do pelvic fractures occur in young individuals?

Answer 1

High energy injuries

Question 2

What type of pelvic fractures occur in older people with osteoporosis?

Answer 2

Low energy pubic rami fractures

Question 3

What forms the pelvic ring?

Answer 3

Ilium, ischium, pubic bone, sacrum and supporting ligaments

Question 4

If the pelvic ring is disrupted in one area, what does this guarantee?

Answer 4

There will be further disruption elsewhere in the ring

Question 5

What arteries and veins are at risk in pelvic fractures?

Answer 5

Internal iliac arteries and pre-sacral venous plexus

Question 6

Nerve roots and branches of where are at risk in pelvic fractures?

Answer 6

Lumbo sacral plexus

Question 7

Describe a lateral compression fracture of the pelvis?

Answer 7

Usually occurs with a side impact (e.g. RTA) where one half of the pelvis is displaced medially

Question 8

Fractures through the pubic rami or ischium are accompanied by what?

Answer 8

Sacral compression fracture or SI joint disruption

Question 9

Describe a vertebral shear fracture of the pelvis?

Answer 9

Occurs due to axial force on one hemipelvis (e.g. fall from height, rapid deceleration) where the affected hemipelvis is displaced superiorly

Question 10

Which leg will look shorter in a vertebral shear fracture of the pelvis?

Answer 10

Affected leg

Question 11

What happens in an anteroposterior compression injury of the pelvis?

Answer 11

Wide disruption of the pubic symphysis (open book fracture)

Question 12

Which type of pelvic fracture has the greatest risk of bleeding?

Answer 12

Anteroposterior compression injury (open book fracture)

Question 13

As pelvic volume increases following a fracture, what else increases?

Answer 13

Degree of displacement

Question 14

How do you treat an open book pelvic fracture?

Answer 14

Promptly reduced to minimise the pelvic volume and allow tamponade of bleeding

Question 15

If you take initial measures to reduce an open book pelvic fracture but there is ongoing haemo-dynamic instability, what should be done?

Answer 15

Angiogram and embolisation, or open packing of the pelvis if already undergoing surgery

Question 16

Why is a PR examination necessary for pelvic fractures?

Answer 16

Assess sacral nerve root function and look for presence of blood

Question 17

What does the presence of blood on a PR exam indicate?

Answer 17

Rectal tear, meaning the injury is an ‘open fracture’ which decreases the prognosis

Question 18

What type of pelvic fracture do low energy pubic rami fractures in the elderly tend to be?

Answer 18

Displaced lateral compression

Question 19

How are low energy pelvic fractures in elderly patients treated?

Answer 19

Conservative management

Question 20

What is the acetabulum?

Answer 20

The intra-articular section of the pelvis

Question 21

Posterior wall fractures of the acetabulum can be associated with what injury?

Answer 21

Hip dislocation

Question 22

What imaging techniques can be used for acetabulum fractures?

Answer 22

X-ray (AP and oblique) and CT

Question 23

How are small, undisplayed acetabular fractures treated?

Answer 23

Conservatively

Question 24

If an acetabular fracture is unstable or displaced in a young patient, how are they treated?

Answer 24

Anatomic reduction and rigid fixation to prevent post traumatic OA

Question 25

If an acetabular fracture is unstable or displaced in an older patient, how are they treated?

Answer 25

Hip replacement