1. Pelvic Ring Fractures
Christy Johnson

2. Outline Background Anatomy and Function Assessment Radiology
Classification
Treatment

3. Background Mechanism: high energy blunt trauma Mortality rate:
15-25% for closed fractures
Up to 50% for open fractures
Hemorrhage is the leading cause of death overall
Venous (80%) > arterial
Have a high index of suspicion for injury of internal iliac vessels or lumbosacral plexus
Arterial injury: superior gluteal most common
Increased mortality a/w SBP < 90, age > 60, increased injury severity score or revised trauma score, need for transfusion > 4 units
Have a high index of suspicion for injury of internal iliac vessels or lumbosacral plexus
Arterial injury: superior gluteal most common (posterior ring injury, APC pattern), internal pudendal (anterior ring, LC pattern), obturator (LC pattern)
Poor outcome associated with SI joint incongruity of > 1cm, leg length discrepancy > 2cm

4. Background Associated injuries: Survivors: 1.89 additional injuries
Chest injury (63%)
Long bone fracture (50%)
Head and abdominal injury (40%)
Spine fractures (25%)
Urogenital injuries in 12-20%
Survivors: 1.89 additional injuries
Non-survivors: 2.95 additional injuries
Only 2 in 14 deaths (14%) are directly attributable to pelvic injury

5. Anatomy: Osteology
Ilium
Sacrum
Femur
Pubis
Ischium

6. Osteology
Ring structure made up of the sacrum and two innominate bones
No inherent osseous stability
Ring structure made up of the sacrum and two innominate bones
No inherent osseous stability. Stability dependent on strong surrounding ligamentous structures
Displacement can only occur with disruption of the ring in two places
Neurovascular structures intimately associated with posterior pelvic ligaments: high index of suspicion for injury of internal iliac vessels or lumbosacral plexus

7. Anatomy: Muscles Iliacus Piriformis Pectineus Sartorius Rectus femoris
Adductor magnus
Pectineus
Adductor longus
Adductor brevis
Anterior

8. Ligaments Anterior structures: provide 40% of stability
Anterior ligaments: symphyseal ligaments- resist external rotation
Anterior structures: provide 40% of stability
Posterior structures: provide 60% of stability

9. Sacrospinous
Ligament:
Resist ER
Pelvic Stabilizers
Iliolumbar:
Augment
posterior
stability
Pelvic floor: sacrospinous ligaments (resist external rotation); sacrotuberous ligametns (resist shear and flexion)
Posterior sacroiliac complex (posterior tension band): strongest ligaments in the body. More important than anterior structures for pelvic ring stability. Anterior sacrolilaic ligaments: resist external rotation after failure of pelvic floor anterior structures. Interosseous sacroiliac: resist anterior-posterior translation of pelvis. Posterior sacroiliac: resist cephalad-caudad displacement of pelvis; Iliolumbar: resist rotation and augment posterior SI ligaments
Sacrotuberous
Ligament:
Resist ER and
Vertical shear
Posterior interosseous sacroiliac ligaments are the strongest in the body

10. Assessment Primary Survey Secondary Survey Airway Breathing
Circulation
Disability
Exposure
Secondary Survey
Pelvis assessed by compression/distraction
Skin evaluation
Smith/Johnson/Cothren et al Journal of Trauma 2007

11. Resuscitation/ Hemorrhage
2 large-bore IVs
2L crystalloid on arrival
Hct/Hgb does NOT correspond to EBL
Hypotension = % EBL
Patients presenting in shock (SBP<90) have mortality rates up to 10 times that of normotensive patients
Starr et al JOT 2002

12. Sites of Hemorrhage External bleeding controlled by direct pressure
Thoracic cavity evaluated by CXR for hemothorax: chest tube if necessary
Abdominal cavity evaluated by a FAST or CT scan in stable patients or ex-lapin unstable patients
If other causes eliminated, then EBL likely from pelvis
Blood replacement as indicated by response to fluid resuscitation
Ratio of FFP: PRBC/ 1:1.5 associated with decreased mortality and transfusion requirements
Injury 2010

13. Physical Exam
Test stability by placing gentle rotational force on each iliac crest
Perform ONCE
Look for external rotation of lower extremity +/- limb-length discrepancy
Perform only once- repeat exams may displace clots or cause neuro injury

14. Physical Exam (continued)
Neurologic exam
L5 and S1 injuries most common
Rectal exam to evaluate sphincter tone and perirectal sensation
Urogenital exam
Concomitant urologic injury 12% of the time
Catheter placement should be preceded by rectal exam, evaluation of meatus, vaginal exam
57% of men with urethral injury show no signs
Vaginal injuries missed in up to 50% of cases
Vaginal and rectal exams
Mandatory to rule out occult open fracture

15. Radiographs Outlet Inlet AP Pelvis Oblique/Judet Obturator oblique
Pelvic Inlet View (AP, beam 45o caudal)
Sacroiliac joints, pelvic brim/ pubic rami, sacrum
Pelvic rim fractures: shows posterior displacement or symphysis widening
Pelvic outlet view (AP beam, 45o cephalad)
Iliac crest, symphysis pubis, sacral foramina
Pelvic ring fractures; shows superior displacement of hemi-pelvis
Oblique/Judet views (beam at affected hip)
A) Obturator oblique (Elevate affected hip 45o)
Findings: obturator foramen
Acetabulum fx: anterior column, posterior wall
B) Iliac oblique (elevate unaffected hip 45o)
Findings: iliac crest, sciatic notches
Acetabulum fx: posterior column, anterior wall
Oblique/Judet
Obturator oblique
Iliac oblique

16. Mechanisms of Pelvic Injury
Anterior Compression
Lateral Compression
Vertical Shear
Combined mechanism
Combined mechanism includes high-energy pelvic fractures produced by a combination of two separate force vectors
Young and Burgess, Rad 1986
Young and Burgess J Trauma 1989

17. AP Compression
Increased incidence of brain, abdominal, visceral, and pelvic injuries; therefore, an increased incidence of shock, sepsis, ARDS, and death.
Occur in pedestrians and motorcyclists

18. Anteroposterior Compression
Type
Definition
APC1
Symphysis widening < 2.5cm
APC2
Symphysis widening > 2.5 cm. Sacrotuberous, sacrospinous and anterior SI joint ligaments are disrupted. Posterior SI ligaments intact.
APC3
Disruption of anterior and posterior SI ligaments. Disruption of sacrospinous and sacrotuberous ligaments

19. Lateral Compression
High incidence of associated brain and visceral injuries
Usually seen in MVAs (car struck from side)
Most common in elderly (mechanism: fall from standing)

20. Lateral Compression Type Definition LC1
Oblique or transverse ramus fracture and ipsilateral anterior sacral ala compression fracture
LC2
Rami fracture and ipsilateral posterior ilium fracture dislocation (crescent fracture)
LC3
Ipsilateral lateral compression and contralateral APC (windswept pelvis). Common mechanism: rollover vehicle or peds struck

21. Vertical Shear

22. Vertical Shear
Associated with the highest risk of hypovolemic shock, mortality
Usually result from falls from height
Posterior and superior directed force
APCIII + vertical displacement

23. Mortality from Pelvic Injuries
Hemodynamic instability + pelvic fracture = 40% mortality
Major cause of death: Hemorrhage (15%)
Major cause of death LC injuries: closed head injuries
Major cause of death APC: combined pelvic and visceral injuries
Hemorrhage in pelvic injuries
Venous bleeding more common than arterial bleeding
Superior gluteal artery (most common arterial injury in APC)
Internal pudendal artery (most common in LC)
Metz et al Orthop Clin N Am 2004
Smith et al J Trauma 2007

24. Circumferential Pelvic Antishock Sheeting
Rapid, inexpensive, temporary means of decreasing pelvic volume
Indications: initial management of an unstable ring injury
Risk of bladder injury in pelvic fractures with internal rotation component (i.e. LC injuries)
Technique: center over greater trochanters (NOT iliac crest/abdomen)

25. External Fixation Advantages: Indications: Contraindications
Decreases pelvic volume
Stabilization of pelvis
Indications:
Pelvic ring injuries with an external rotation component (APC, VS)
Unstable ring injury w/ ongoing blood loss
Contraindications
Ilium fracture that precludes safe application
Acetabular fracture
Technique: Iliac wing or supra- acetabular pins
Egbers Orthopade 1992

26. Angiography/ Embolism
Small percentage of pelvic fractures have significant arterial injuries amendable to angio (10%)
Must have stabilized pelvis (pattern or ex-fix) because most bleeding is venous which will tamponade
Eliminate other sources of bleeding
Successful in 70-90% of cases but takes 3-4hrs

27. Treatment Overview Nonoperative Operative
Indicated for mechanically stable pelvic ring injuries
LC1: anterior impaction fracture of sacrum and oblique ramus fx with <1cm of posterior ring displacement
APC1: widening of symphysis <2.5 cm with intact posterior pelvic ring
Isolated pubic ramus fx
Operative
Anterior ring stabilization: Symphyseal fixation
Posterior ring stabilization
Anterior or posterior SI joint fixation
Sacral bar
Iliac wing fixation

28. Treatment Comparison Technique Pro Con Pubic Symphysis Plating
Can be done simultaneously w/ laparotomy
Only stabilizes anterior ring
Posterior approach- ORIF
Visualization of reduction and sacral screw placement; limits risk of neurologic injury
Prominent hardware complications
Anterior approach – ORIF
Allows for placement of multiple plates across the SI joint
Risk of L4 and L5 injury
Percutaneous Iliosacral screw
Good for sacral fx and SI dislocations; low soft tissue complications
Neurologic injury; technically demanding

29. Tenets of Fixation Complete instability of posterior ring:
Anterior fixation alone is inadequate for maintaining reduction
Complete instability of posterior ring with vertical (cephalad) displacement
Posterior fixation should be supplemented with anterior stabilization
Posterior injury is regarded as the more critical and in need of accurate reduction with stable fixation
Reduction generally proceeds from back to front

30. Summary Pelvic ring injuries are highly associated with other injuries
Evaluation of pelvic stability is critical and requires an understanding of mechanism of injury, a careful examination, and scrutiny of radiographic imaging
Management requires an interdisciplinary approach and may be life saving

31. Questions? Thanks to: Dr. Helfet Matt Griffith Chris Mattem
Milton Little