Anatomy, Radiographic Evaluation, and Classification of Pelvic Ring Injuries

Robert M. Harris MD Medical Director of Orthopaedic Trauma Mountain States Health Alliance East Tenn State University Quillen School of Medicine Revised November 2010 Created March 2004 Revised April 2007 By Kyle Dickson MD

Pelvic Ring Disruption

• • • Marker for severe injury Overall mortality 6 10% Life threatening

Magnitude of Forces

• • ACL injury 500-1000N LC-I pelvic fracture 6000-9000N

Bone Anatomy

 Two innominate bones with sacrum.

 Coalesce at triradiate cartilage.

• •  Ilium, ishium and pubis have three separate ossification centers that fuse at sixteen years.

Gap in symphysis < 5 mm SI joint 2-4 mm

Ligamentous Anatomy

• Ligaments - posterior ligaments are stronger than anterior ligaments:  Posterior SI  Anterior SI  Interosseous ligaments  Pubic symphysis  Sacrotuberous  Sacrospinous

Ligamentous

ASI ST SS

ANATOMY

PSI ST

• • • • •

Posterior Ligaments

Ant. SI Joint – resist external rotation Post. SI and Interosseous – posterior stability by tension band (strongest in body) Iliolumbar ligaments augments posterior complex Sacrotuberous (sacrum behind sacro-spinous into ischial tuberosily vertically)Resists shear and flexion of SI joint Sacrospinous – (anterior sacral body to ischial spine horizontally) resists external rotation

Normal SI Joint Motion with Gait

• • • < 6 mm of translation < 6° rotation Intact cadaver resist 5,837 N (1,212 lbs)

ANATOMY

Relationships

Vascular Anatomy

• • • Internal iliac artery courses medial to the vein, splits into anterior and posterior branches. Posterior branch is more likely injured (SGA is largest branch).

Usual bleeding is from venous plexus.

Potentially Damaged Visceral Anatomy

• Blunt vs. impaled by bony spike – Bladder/urethra – Rectum – Vagina

Pelvic Stability

• • Strength of ring: 40% anterior and 60% posterior.

V sphere = 4/3  r³.

• Stability – ability of pelvic ring to withstand physiologic forces without abnormal deformation

IDENTIFY THE HIGH RISK PELVIC DISRUPTION

By Radiography By Physical Exam

Physical Exam

• Physical Exam-poor sensitivity (8%) for mechanically unstable pelvis fractures in blunt trauma patients • Shlamovitz GZ, Mower WR, Morgan MT-Journal of Trauma Mar 09

Radiographs

• • • • • Anteroposterior (AP) Inlet (40° caudad) Outlet (40 ° cephalad) CT scan Judet (acetabular fractures)

AP VIEW

If evidence of pelvic ring fracture...

INLET VIEW

Inlet (Caudad) View

• • • Horizontal Plane Rotation Posterior Displacement Sacral ala

OUTLET VIEW

Outlet (Cephalad) View

• • • Sacrum Cephalad Displacement Sacral Foramina

CT Scan

• • • • • Better defines posterior injury Amount of displacement versus impaction Rotation of fragments Amount of comminution Assess neural foramina

CT SCAN

3D CT

Radiographic Signs of Instability

• • • Sacroiliac displacement of 5 mm in any plane Posterior fracture gap (rather than impaction) Avulsion of fifth lumbar transverse process, lateral border of sacrum (sacrotuberous ligament), or ischial spine (sacrospinous ligament)

Translational Deformities

• • • X axis – Diastasis or impaction Y axis – Caudad or cephalad displacement Z axis – Anterior or posterior displacement

Rotational Deformities

• • • X axis – Flexion or extension Y axis – Internal rotation or external rotation Z axis – Abduction or adduction

Classification

• • • • Aids in predicting hemodynamic instability Aids in predicting visceral and g.u. injuries Aids in predicting pelvic instability Aids in understanding mechanism of injury, force vector of injury, and surgical tactic for reduction

Classification Systems

• • • • Anatomical (Letournel) Stability & Deformity (Pennal, Bucholz, Tile) Vector force and associated injuries (Young & Burgess) OTA-research

Anatomical Classification (Letournel) Where The Pelvis Breaks

Anterior Posterior

• • Rami fractures Symphyseal disruption • • • • • Iliac wing fracture Iliac wing/sacroiliac (SI) joint (crescent fracture) SI joint Sacrum/SI joint Sacrum fracture

• Pennal, 1961 Bucholz, 1981 Tile, 1988 Magnitude and direction of forces – Lateral posterior compression (LC) – Anterior posterior compression (APC) – Vertical shear (VS) • Added stability to the classification

Tile Classification

• • • Type A: Stable fracture.

Type B: Rotationally unstable, but vertically stable.

Type C: Rotationally and vertically unstable.

OTA/AO – Pelvic Injury Classification

• • 61A – Lesion sparing (or with no displacement of ) posterior arch • B – Incomplete disruption at posterior arch; partially stable C – Complete disruption of posterior arch; unstable

A Fractures – Ring Intact

• • • A-1 – Fracture of innominate bone; avulsion A-2 – Fracture of innominate bone; direct blow A-3 – Transverse fracture of sacrum and coccyx

B-Ring Injury – Partially stable

• • • B-1 – Unilateral partial disruption of posterior arch, external rotation (“open book” injury) B-2 – Unilateral, partial disruption of posterior arch, internal rotation (lateral compression injury) B-3 – Bilateral, partial lesion of posterior arch

C – Complete Disruption Posterior Arch, Unstable Pelvis • • • C-1 – Unilateral, complete disruption of posterior arch C-2 – Bilateral, ipsilateral complete, contralateral incomplete C –3 – Bilateral, complete disruption

Young-Burgess Radiology 1986

• • • Based on mechanism of injury Predictive of associated local & distant injury Useful for planning acute treatment

MECHANISM OF INJURY (MOI) • Do initial radiographs agree with MOI in pelvic ring disruptions Linnau KF, Blackmore CC, Routt ML, Mock CN-J Ortho Trauma Jul 2007 • more reliable for LC than AP mechanisms

MECHANISM OF INJURY

• Lateral compression (implosion) • AP compression (external rotation) • Vertical shear • Combined injury

Young-Burgess Classification 

LATERAL COMPRESSION fracture of anterior ring plus:



LC -I Compression fracture of anterior sacrum



LC -II Iliac wing fracture posteriorly (unstable)



LC -III Windswept pelvis (contralateral SI injury)



ANTERIOR-POSTERIOR COMPRESSION



APC - I Partial disruption



APC - II Posterior sacroiliac ligaments intact



APC - III Posterior sacroiliac ligaments disrupted



VERTICAL SHEAR cephlad and posterior displacement



COMBINED MECHANISM (LC & VS most common)

CLASSIFICATION

Mechanism and direction of injury

DISRUPTED PELVIC RING

• Posterior/SI injury is a marker for associated vascular injuries • Tamponade efforts and fluid resuscitation may be rendered useless

Resuscitation

• Young and Burgess classification: – LC III – APC II – APC III – VS – CM

RESUSCITATION REQUIREMENTS

units blood 1st 24 hours 40 35 30 25 20 15 10 5 0 2.3

LC-I 7.4

3.1

LC-II LC-III 9.4

VS 7.6

35.4

AP-II AP-III

Mortality

: Deaths

6.60% 0% VS LC 20% APC

Interobserver Reliability of the Young/Burgess and Tile classifications • Koo H, Leveridge M, McKee,MD, Schemitsch EH, J Ortho Trauma Jul 2008 – Young/Burgess –Kappa .72-better for the training surgeon – CT-improved assessment of stability • Furey AJ, O”Toole RV, Turen C, Ortho June 2009 – Interobserver – moderate degree of agreement – Intraobserver- moderate for Tile • Substantial for Burgess

LATERAL COMPRESSION

LC I: Sacral compression

Lateral Compression

• • • • Most common pattern.

LC1 – stable, load to posterior ring.

LC2 – load to anterior ring, posterior ligaments injured, ST and SS intact.

LC3 – LC2 + external rotation injury of the other side.

LC-I

LATERAL COMPRESSION

Common anterior pattern

LATERAL COMPRESSION

LC I: Sacral compression

What Constitutes a LCI

• Lefaivre KA, Padalecki JR, Starr AJ- J Ortho Trauma Jan 2009 • LC I-Spectrum of injuries • Complete sacral disruptions – Denis classification – Predicted by severity of anterior pelvic ring disruption – Abdominal AIS – Rami fracture location – ISS

LATERAL COMPRESSION

LC II: Iliac wing fracture

LC-II

LC-II

LC III: “ Windswept pelvis”

LC III

LC III

LC III

Anteroposterior Compression

• • • APC1- stable injury, anterior ligament injury.

APC2 – SS and anterior SI injury, possibly ST.

APC3 – anterior and posterior injury, completely unstable.

ANTEROPOSTERIOR COMPRESSION

AP I: Hockey player

• Note that the ligaments are stretched, and not torn

AP I

ANTEROPOSTERIOR COMPRESSION APII: Open book pelvis

AP II

• • APC-2 – Sacrotuberous, sacrospinous, and anterior SI joint ligaments disrupted (post SI ligaments intact) Note: pelvic floor ligaments are violated, as well as anterior SI ligaments

AP-II

AP II

Ligamentous pathology

AP II

These anterior SI ligaments are disrupted...

But these posterior SI ligaments remain intact

ANTEROPOSTERIOR COMPRESSION

APC III: Complete iliosacral dissociation

• APC-3 – Complete SI joint disruption • (usually not vertically displaced)

AP III

APC-III

AP III

ASSOCIATED INJURIES

Lateral Compression:   

Abdominal visceral injury Head injury Few pelvic vascular injuries

AP Compression: 

Urologic injury



Hemorrhage/pelvic vascular injury: APCII-10%, APCIII-22%

Vertical Shear

• • • Always unstable Ant. symphsis or vertical rami fractures post. Injury variable Vertical displacement

VERTICAL SHEAR

Vertically unstable – often due to a unilateral injury.

Similar to APC3.

VERTICAL SHEAR

COMBINED MECHANICAL INJURY Combined vectors occasionally 2 separate injuries (ejection/landing) Often LC/VS, or AP/VS

COMBINED MECHANICAL INJURY

CLASSIFY INJURY (Young-Burgess) LC-I, AP-I Conservative Treatment AP-II AP-III, VS Anterior Stabilization Anterior and Posterior Stabilization

Surgeon variability in the treatment of pelvic ring injuries • • • Furey AJ, O”Toole RV, Nascone JW, Sciadini MF- Ortho Oct 2010 Young and Burgess, and Tile Classifications Kappa Value – Intraobserver- 0.56 moderate agreement – Interobserver- 0.47 moderate agreement • Consistent treatment for certain patterns

References

• • • • •

Surgeon variability in the treatment of pelvic ring injuries.

Furey AJ , O'Toole RV , Nascone JW , Copeland CE , Turen C , Sciadini MF . Orthopedics. 2010 Oct 11;33(10) .

Classification of pelvic fractures: analysis of inter- and intraobserver variability using the Young-Burgess and Tile classification systems.

Furey AJ , O'Toole RV , Nascone JW , Sciadini MF , Copeland CE , Turen C . Orthopedics. 2009 Jun;32(6):401

Interobserver reliability of the young-burgess and tile classification systems for fractures of the pelvic ring.

Koo H , Leveridge M , Thompson C , Zdero R , Bhandari M , Kreder HJ , Stephen D , McKee MD , Schemitsch EH .

Division of Orthopaedic Surgery; and daggerMartin Orthopaedic Biomechanics Lab, St. Michael's Hospital, Toronto, Ontario, Canada. J Orthop Trauma. 2008 Jul;22(6):379-84

Fracture of the pelvis: current concepts of classification.

75.

Young JW , Resnik CS .Department of Radiology, University of Maryland Medical System/Hospital, Baltimore 21201. AJR Am J Roentgenol. 1990 Dec;155(6):1169-

Do initial radiographs agree with crash site mechanism of injury in pelvic ring disruptions? A pilot study.

Linnau KF , Blackmore CC , Kaufman R , Nguyen TN , Routt ML Jr , Stambaugh LE 3rd , Jurkovich GJ , Mock CN .Department of Radiology, Harborview Medical Center, Seattle, Washington 98104-2499, USA. J Orthop Trauma. 2007 Jul;21(6):375-80.

References

• • • • • •

How (un)useful is the pelvic ring stability examination in diagnosing mechanically unstable pelvic fractures in blunt trauma patients?

Shlamovitz GZ , Mower WR , Bergman J , Chuang KR , Crisp J , Hardy D , Sargent M , Shroff SD , Snyder E , Morgan MT . Department of Emergency Medicine and Traumatology, Hartford Hospital, UCONN School of Medicine, University of Connecticut, Hartford, Connecticut, USA. J Trauma. 2009 Mar;66(3):815-20

What constitutes a Young and Burgess lateral compression-I (OTA 61-B2) pelvic ring disruption? A description of computed tomography-based fracture anatomy and associated injuries.

Lefaivre KA , Padalecki JR , Starr AJ . Department of Orthopaedics Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA. J Orthop Trauma. 2009 Jan;23(1):16-21.

Predicting blood loss in isolated pelvic and acetabular high-energy trauma.

Magnussen RA , Tressler MA , Obremskey WT , Kregor PJ . Division of Orthopaedic Trauma, Vanderbilt Orthopaedic Institute, Nashville, Tennessee 37232-8774, USA. Orthop Trauma. 2007 Oct;21(9):603-7

Pelvic disruption: assessment and classification.

Pennal GF , Tile M , Waddell JP , Garside H . Clin Orthop Relat Res. 1980 Sep;(151):12-21

Pelvic fractures: value of plain radiography in early assessment and management.

Young JW , Burgess AR , Brumback RJ , Poka A . Radiology. 1986 Aug;160(2):445-51

Pelvic ring disruptions: effective classification system and treatment protocols.

Burgess AR , Eastridge BJ , Young JW , Ellison TS , Ellison PS Jr , Poka A , Bathon GH , Brumback RJ .

Shock Trauma Center, Maryland Institute for Emergency Medical Services Systems, Baltimore J Trauma. 1990 Jul;30(7):848-56

See Emergent Management of Pelvic Injuries for Application of Classification to Treatment

Acknowledgment

Andy Burgess and Kyle Dickson for the use of their slides If you would like to volunteer as an author for the Resident Slide Project or recommend updates to any of the following slides, please send an e-mail to [email protected]

E-mail OTA about Questions/Comments

Return to Pelvis Index