Pelvic Ring Injuries

Question 1

What is the mortality rate of pelvic fractures?

Answer 1

15-25% for closed injuries
up to 50% for open injuries
Hemorrhage is the leading cause of death overall
increased mortality associated with:
1) systolic BP 60 years
3) increased Injury Severity Score (ISS) or Revised Trauma Score (RTS)
4) need for transfusion > 4 units

Question 2

Blunt head trauma is most commonly a/w which type of pelvic fracture?

Answer 2

Lateral compression; closed head injury is MC cause of death in LC injuries
In APC is combo pelvic and visceral injuries

Question 3

What is the most common associated injury in pelvic ring fractures?

Answer 3

Chest injuries; 63%
long bone fractures in 50%
sexual dysfunction up to 50% 
head and abdominal injury in 40%
spine fractures in 25%

Question 4

What are indicators of poor outcomes in pelvic ring injuries?

Answer 4

SI joint incongruity of > 1 cm
high degree initial displacement
malunion or residual displacement
leg length discrepancy > 2 cm
nonunion
neurologic injury
urethral injury

Question 5

In a high energy pelvic ring injury what imaging studies are mandatory?

Answer 5

1) AP pelvis
2) Lateral C-spine
3) AP chest
4) CT pelvis

Should also obtain inlet/outlet views and Judet views

Question 6

What is the initial ED management of pelvic ring injury?

Answer 6

Placement of a pelvic binder; use of sheet is adequate, place over trochanters

Question 7

What nerve is most at risk when applying the external fixator on the pelvis using a minimally invasive fluoroscopic technique of pin insertion?

Answer 7

The lateral femoral cutaneous n.

Question 8

Which pelvic ring injuries can be WBAT and treated non-operatively?

Answer 8

1) LC I
2) APC I
3) Isolated pubic rami fxs

Question 9

What approach is used for plating of the pubic symphysis?

Answer 9

Pfannenstiel

Question 10

Anterior sacroiliac plating is a/w what complication?

Answer 10

risk of L4 and L5 injury with placement of anterior sacral retractors

Question 11

Placement of sacroiliac screws is safest in which sacral body?

Answer 11

S1

Question 12

Which views are used for SI screw placement?

Answer 12

Outlet view- shows superior/inferior position of screw

Inlet view- shows anterior/posterior position of screw

Question 13

What complication is a/w with errant SI screw placement?

Answer 13

L5 nerve root injury

Question 14

Alternating single-leg-stance radiographs are most helpful for evaluation of which of the following diagnoses?

Answer 14

Chronic pelvis instability

Question 15

A lateral sacral view is used for proper placement of which of the following fixation methods?

Answer 15

Percutaneous SI screws

Question 16

Injury to the L5 nerve root would manifest as?

Answer 16

weakness in great toe extension and sensory changes on the dorsum of the foot. L5 often partially innervates tibialis anterior along with L4, so weakness to ankle dorsiflexion may be present as well.

Question 17

Of all the pelvic ring injury types, anteroposterior compression type III pelvic ring injuries have the highest rate of which of the following?

Answer 17

mortality, blood loss, and need for transfusion

Also have high rate of urogenital and abdominal injury

Question 18

What risk factor leads to the highest rate of postoperative loss of reduction in unstable posterior pelvic ring injuries?

Answer 18

Vertical sacral fracture

Question 19

Sacral fractures are commonly missed how often do they occur with pelvic injuries and how often are they missed?

Answer 19

Occur 30-45% with pelvic injuries
Missed 50-75% of the time
25% are a/w neurological injury

Question 20

Diminished perianal sensation in a sacral fx is a/w with what nerve root injury?

Answer 20

S2

Question 21

What is the classification for sacral fractures?

Answer 21

Denis:
I- lateral to sacral foramina; 6% nerve injury
II- intraforaminal; 28% nerve injury
III- Medial to sacral foramina; 57% nerve injury

Also there are
T-shaped; higher incidence of nerve dysfunction
U-shaped or H-shaped; represents sacropelvis dissociation

Question 22

What is the most stable construct for fixation of an unstable transforaminal sacral fractures?

Answer 22

Combined iliosacral and lumbopelvic fixation (triangular osteosynthesis)

Question 23

What is the classification for pelvic fractures?

Answer 23

Young-Burgess (APC, LC or combined)
APC I- 2.5cm PS widening, SS/ST and SI ligaments torn

LC I- Pubic rami fxs and ipsilateral sacral ala fx
LC II- pubi rami fxs and ispilateral posterior ilium fracture dislocation (crescent fracture)
LC III- LC injury with contralateral APC injury (windswept pelvis)

Vertical shear- highest risk of hypovolemic shock (63%), 25% mortality