Chapter 97- Pelvic, Acetabular, and Sacral Fractures

Question 1

corona mortis

Answer 1

anastamosis between the external iliac a(sometimes the deep inferior epigastic a) and the obturator artery

Question 2

LC fracture patterns are associated with what other injury?

Answer 2

head injury (high rate of mortality)

Question 3

LC1

Answer 3

pubic rami fx, plus sacral impaction

Question 4

LCII

Answer 4

rami fractures plus crescent fracture of the sacrum
- or posterior sacral ligamentous injury

Question 5

LCIII

Answer 5

windswept pelvis - rami plus crescent on one side, anterior sacral ligaments torn on contralateral side with external rotation deformity

Question 6

APCI

Answer 6

pubic symphysis diastasis <2.5cm

Question 7

APCII

Answer 7

anterior symphyseal widenind >2.5cm, anterior SI ligaments torn, poterior intact

Question 8

APCIII

Answer 8

posterios SI ligaments torn - complete dissociation of the SI joint

Question 9

APC injuries associated with what injuries?

Answer 9

visceral injuries

Question 10

what does an inlet film demonstrate in SI fixation

Answer 10

anterior posterior extents of osseous safety

Question 11

what does an outlet view demonstrate in SI fixation?

Answer 11

cranial-caudal extent of osseous safety

Question 12

safe zone for SI screw insertion on a lateral of the sacrum?

Answer 12

postero superior or antero inferior
posteroinferior endangers s1 nerve root
anterosuperior endangers L5 nerve root

Question 13

incidence of DVT in pelvic ring injuries

Answer 13

35-50%

Question 14

elementary pattern acetabulum fractures

Answer 14

anterior column
anterior wall
posterior column
posterior wall - gull sign on obturator oblique
transverse (looks like a line running anterior to posterior on an axial CT)

Question 15

elementary pattern acetabulum fractures

Answer 15

posterior column-posterior all
transverse-posterior wall
t-type
anterior column - posterior hemitransverse
associated both column (spur sign - no articular piece connected to the ilium any longer)

Question 16

what approach to use for posterior-ly based fractures?

Answer 16

• posterior wall
• posterior column
• posterior wall posterior column
• transverse
• transverse-posterior wall
  +/- t-type

KOCHER LANGENBECK

Question 17

ilioinguinal approach

Answer 17

• use for ABC, t-type, transverse, anterior column
• lateral window = subperiosteal dissection of the iliacus to the iliac fossa
• middle window = incise the external oblique and reflect it distal
  – lateral portion of middle window contains iliopsoas tendon and femoral nerve
  –medial portion of middle window contains inguinal a, veing, lymphatics
  – iliopectineal fascia divides these two compartments
• medial window = lateral mobilization of the spermatic cord or round ligament
• LFCN can be found just deep to the inguinal ligament at the AISI

Question 18

when to use an extended iliofemoral approach

Answer 18

chronic (>3weeks acetabulum)
complex abcs, sciatic buttress comminution

Question 19

Stoppa/AIP (anterior intrapelvic)

Answer 19

can be used as a substitute for the medial window (eg Stoppa/lateral window approach)
- retropubic dissection
- useful for intrapelvic work/reduction of the inner quadrilateral surface
- - associated both columns and anterior column fractures

Question 20

maneuver for performing exam under fluoro of an acetabular fracture?

Answer 20

adduction, flexion, and internal rotation of the affected hip with gental axial force

Question 21

iliac oblique

Answer 21

anterior wall
posterior column
sciatic notch
iliac fossa

Question 22

obturator oblique

Answer 22

anterior column
posterior wall
obturator sulcus

Question 23

secondary congruence may be seen in what type of acetabular fractures

Answer 23

associated both column in the elderly

Question 24

HO prophylaxis options

Answer 24

indomethacin 25mg TID x 6-12 weeks
700cGy radiation within 72 hours of fracture fixation

Question 25

to avoid avascular necrosis of the femoral head, care should be taken to protect what artery during ORIF of the acetabulum?

Answer 25

ascending branch of the medial femoral circumflex a

Question 26

Zone I sacral fracture

Answer 26

lateral to the foramen
most common
lowest incidence of neurologic injury

Question 27

Zone II sacral fracture

Answer 27

thru the foramen
30% with unilateral nerve injury L5, S1, S2

Question 28

Zone III sacral fracture

Answer 28

medial to the foramen
highest rate of neurologic dysfunction
76% of patients with bowel, bladder, or sexual dysfunction
least common of the sacral fractures

Question 29

APCIII fracture has highest risk of what of all the pelvic ring injuries

Answer 29

highest fluid requirements
highest risk of hemorrhage
highest risk of mortality