Radiographic evaluation anatomy and classification of pelvic ring injuries
This presentation is the property of its rightful owner.
Sponsored Links
1 / 136

Radiographic Evaluation, Anatomy, and Classification of Pelvic Ring Injuries PowerPoint PPT Presentation


  • 153 Views
  • Uploaded on
  • Presentation posted in: General

Radiographic Evaluation, Anatomy, and Classification of Pelvic Ring Injuries. Kyle F. Dickson, MD Chief of Orthopaedics, Charity Hospital Director of Orthopaedic Trauma Tulane University Created March 2004 Reviewed April 2007. Palpable Bony Landmarks. Symphysis Pubis

Download Presentation

Radiographic Evaluation, Anatomy, and Classification of Pelvic Ring Injuries

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Radiographic Evaluation, Anatomy, and Classification of Pelvic Ring Injuries

Kyle F. Dickson, MD

Chief of Orthopaedics, Charity Hospital

Director of Orthopaedic Trauma

Tulane UniversityCreated March 2004Reviewed April 2007


Palpable Bony Landmarks

  • Symphysis Pubis

  • Anterior Superior Iliac Spine (ASIS)

  • Iliac Wing

  • Posterior Superior Iliac Spine (PSIS)


Pelvic Ring

  • 2 innominate bones

  • 1 Sacrum

  • Gap in symphysis < 5 mm

  • SI joint 2-4 mm


Important Stabilizing Ligaments

  • Posterior Iliosacral

  • Anterior Iliosacral

  • Sacrospinous

  • Sacrotuberous

  • Symphyseal


Important Muscles

  • Gluteus Maximus

  • Iliopsoas

  • Rectus Abdominus


Possible Arterial Bleeders in Pelvic Injuries

  • Iliolumbar artery

  • Superior gluteal artery

  • Lateral sacral artery

  • Internal iliac artery

  • Internal pudendal (active bleeding most commonly found)


Neurologic Damage

  • L5 & S1, most common

  • L2 to S4 possible

  • Dependent on location of fracture and amount of displacement


Denis, CORR 1988

  • Sacral Fractures – Neurologic Injury

    • Lateral to foramen – 6% injury

    • Through foramen – 28% injury

    • Medial to foramen – 57% injury


Pohlemann, CORR 1994

  • Amount of displacement move important then location


Potentially Damaged Visceral Anatomy

  • Blunt vs. impaled by bony spike

    • Bladder/urethra

    • Rectum

    • Vagina


Pelvic Ring

  • No inherent stability

  • Ligaments give the pelvis stability


Symphyseal Ligaments

  • Resist external rotation in double-leg stance

  • Rami act as struts to resist compressive and internal rotation in single leg stance

  • Sectioning causes little pelvic instability


Ghanayem, J Trauma 1995

  • Abdominal wall contributes to pelvic stability (laparotomy increased pelvic displacement in cadaveric model)


SI Joint Transfers Load from Appendicular to Axial Skeleton


Sacrum

  • Inlet View Reverse keystone where compression forces displace sacrum anteriorly

  • Outlet View True keystone compression locks sacrum into pelvic ring

  • Small rotating movements during gait


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)


Nachemson, Acta Orthop Scand 1966

  • Sitting 710 N (160 lbs) at each Si joint

  • Lying 196 N (44 lbs)

  • Lateral decubitus 686 N (154 lbs)

  • Standing 980 N (220 lbs)


Sitting or Double Leg Stance

  • Pubic rami tension and compression posteriorly

  • External rotation injury – displaces in sitting or double leg stance


Single Leg Stance

  • Tension shear posteriorly and compression of rami

  • Will displace internal rotation injury


Direction of Force

  • Anteroposterior

  • Lateral compression

  • Vertical shear


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


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


Deformity of Pelvis

  • Defined from an anatomically positioned pelvis in space

  • Deformity a combination of rotational & translational deformities


Deformity of Pelvis (cont.)

  • Does not deform around a single point but can be represented as a vector from a normally positioned pelvis

  • Acute deformity difficult to measure but direction often able to be determined


Pelvic Instability

  • These injuries which will have worsening deformity

  • Physical exam and radiographic evaluation


Determining Stability

  • Integrity of posterior bone and ligament, unstable = vertical plane displacement

  • Some partial instability in rotation


Physical Exam

  • Symmetrical palpable ASIS, iliac wing, and symphysis

  • ASIS compression test

  • Iliac wing compression test


Radiographic Evaluation

  • Anteroposterior view (AP)

  • Inlet view (40° caudad)

  • Outlet view (40 ° cephalad)

  • CT


Good Quality Radiographsare Essential


Inlet (Caudad) View

  • Horizontal Plane Rotation

  • Posterior Displacement

  • Sacral ala


Outlet (Cephalad) View

  • Sacrum

  • Cephalad Displacement

  • Sacral Foramina


Placement of Wires Show

  • Ant. SI joint lateral to post. SI

  • Radiographic brim does not always correlate with anatomical brim


CT Scan

  • Better defines posterior injury

  • Amount of displacement versus impaction

  • Rotation of fragments

  • Amount of comminution

  • Assess neural foramina


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)


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)


Anatomical Classification(Letournel)

Where The Pelvis Breaks


Posterior

  • Iliac wing fracture

  • Iliac wing/sacroiliac (SI) joint (crescent fracture)

  • SI joint

  • Sacrum/SI joint

  • Sacrum fracture


Anterior

  • Rami fractures

  • Symphyseal disruption


Pennal, 1961

  • Magnitude and direction of forces

    • Lateral posterior compression (LC)

    • Anterior posterior compression (APC)

    • Vertical shear (VS)


Bucholz, 1981 Tile, 1988

Added stability to the classification


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


Further Classification

  • A.1 – Location of avulsion

  • A.2 – Type of fracture anteriorly

  • A.3 – Amount of displacement sacrum


Further Classification (cont.)

  • B – Location of fracture


Further Classification (cont.)

  • C – Location of fractures – iliac wing, SI joint, and sacrum


Young and Burgess, Rad 1986

  • Increases clinicians diagnosis of frequently missed lesions

  • Predictive index for associated injuries

  • Helps clinicians to select treatment based on probable pathology and hemodynamic status


Lateral Compression

  • LC-1 – Ant. superior inf. rami or symphysis and compression of sacrum same side

  • LC-2 - LC-1 – anteriorly and posteriorly crescent fracture near anterior border at SI joint  Ileum rotated internally


Lateral Compression

LC I: Sacral compression


Patient WH

  • Progressive IR deformity that became fixed

  • Required anterior release & post sacral osteotomy followed by external rotation

  • Pre-& postop, AP and inlet, and 2 year follow-up


Lateral Compression

LC II: Iliac wing fracture


LC (cont.)

  • LC-3 – Windswept pelvis – LCI or II on one side of the pelvis and open book (APC) on contralateral side (roll over mechanism by IR on LC side and ER on contralateral side)


LC III: “Windswept pelvis”


LC III


Anteroposterior Compression

  • Diastasis anteriorly through symphysis pubis or vertical Rami fractures

  • Posteriorly usually through SI joint – amount of displacement defines subset


Anteroposterior(cont.)

  • APC-1 – 1-2 cm symphysis diastasis and minimal SI diastasis anteriorly (external rotation of hemipelvis – stable pelvis).


AP I

  • Note that the ligaments are stretched, and not torn


Anteroposterior (cont.)

  • APC-2 – Sacrotuberous, sacrospinous, and anterior SI joint ligaments disrupted (post SI ligaments intact)

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


AP II

  • Note: pelvic floor ligaments are violated, as well as anterior SI ligaments


Anteroposterior Compression

APC III: Complete Iliosacral Dissociation


Vertical Shear

  • Always unstable

  • Ant. symphsis or vertical rami fractures-post. Injury variable

  • Vertical displacement


Vertical Shear


Patient NJ

  • VS initially attempted to be treated with anterior plate and ex-fix with hardware failure

  • 3 stage pelvic reconstruction ( ant.  post ant. 2 yr follow-up – Auburn football player)


Combined

  • Combined vectors occasionally 2 separate injuries (ejection/landing)

  • Often LC/VS, or AP/VS


Combined Mechanical Injury


Patient LC

  • Combination LC and VS

  • Treated conservatively initially

  • Required 3 stage pelvic reconstruction to restore ischial height


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


Acknowledgment

Joel Matta, Phil Kregor, and Mark

Vrahas 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


  • Login