Anatomy, Radiographic Evaluation, and Classification of Pelvic Ring Injuries Robert M. Harris MD...

download Anatomy, Radiographic Evaluation, and Classification of Pelvic Ring Injuries Robert M. Harris MD Medical Director of Orthopaedic Trauma Mountain States

of 83

  • date post

    29-Mar-2015
  • Category

    Documents

  • view

    223
  • download

    4

Embed Size (px)

Transcript of Anatomy, Radiographic Evaluation, and Classification of Pelvic Ring Injuries Robert M. Harris MD...

  • Slide 1

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 Slide 2 Marker for severe injury Overall mortality 6- 10% Life threatening Pelvic Ring Disruption Slide 3 Magnitude of Forces ACL injury 500-1000N LC-I pelvic fracture 6000-9000N Slide 4 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 Slide 5 Ligamentous Anatomy Ligaments - posterior ligaments are stronger than anterior ligaments: l Posterior SI l Anterior SI l Interosseous ligaments l Pubic symphysis l Sacrotuberous l Sacrospinous Slide 6 ANATOMY Ligamentous ASI ST SS PSI ST Slide 7 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 Slide 8 Normal SI Joint Motion with Gait < 6 mm of translation < 6 rotation Intact cadaver resist 5,837 N (1,212 lbs) Slide 9 ANATOMY Relationships Slide 10 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. Slide 11 Potentially Damaged Visceral Anatomy Blunt vs. impaled by bony spike Bladder/urethra Rectum Vagina Slide 12 Pelvic Stability Strength of ring: 40% anterior and 60% posterior. V sphere = 4/3 r. Stability ability of pelvic ring to withstand physiologic forces without abnormal deformation Slide 13 IDENTIFY THE HIGH RISK PELVIC DISRUPTION By Physical Exam By Radiography Slide 14 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 Slide 15 Radiographs Anteroposterior (AP) Inlet (40 caudad) Outlet (40 cephalad) CT scan Judet (acetabular fractures) Slide 16 AP VIEW If evidence of pelvic ring fracture... Slide 17 INLET VIEW Slide 18 Inlet (Caudad) View Horizontal Plane Rotation Posterior Displacement Sacral ala Slide 19 OUTLET VIEW Slide 20 Outlet (Cephalad) View Sacrum Cephalad Displacement Sacral Foramina Slide 21 CT Scan Better defines posterior injury Amount of displacement versus impaction Rotation of fragments Amount of comminution Assess neural foramina Slide 22 CT SCAN Slide 23 3D CT Slide 24 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) Slide 25 Translational Deformities X axis Diastasis or impaction Y axis Caudad or cephalad displacement Z axis Anterior or posterior displacement Slide 26 Rotational Deformities X axis Flexion or extension Y axis Internal rotation or external rotation Z axis Abduction or adduction Slide 27 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 Slide 28 Classification Systems Anatomical (Letournel) Stability & Deformity (Pennal, Bucholz, Tile) Vector force and associated injuries (Young & Burgess) OTA-research Slide 29 Anatomical Classification (Letournel) Where The Pelvis Breaks Slide 30 Anterior Posterior Rami fractures Symphyseal disruption Iliac wing fracture Iliac wing/sacroiliac (SI) joint (crescent fracture) SI joint Sacrum/SI joint Sacrum fracture Slide 31 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 Slide 32 Tile Classification Type A: Stable fracture. Type B: Rotationally unstable, but vertically stable. Type C: Rotationally and vertically unstable. Slide 33 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 Slide 34 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 Slide 35 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 Slide 36 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 Slide 37 Young-Burgess Radiology 1986 Based on mechanism of injury Predictive of associated local & distant injury Useful for planning acute treatment Slide 38 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 Slide 39 MECHANISM OF INJURY Lateral compression Lateral compression (implosion) AP compression AP compression (external rotation) Vertical shear Vertical shear Combined injury Combined injury Slide 40 LATERAL COMPRESSION fracture of anterior ring plus: LATERAL COMPRESSION fracture of anterior ring plus: LC -I Compression fracture of anterior sacrum LC -I Compression fracture of anterior sacrum LC -II Iliac wing fracture posteriorly (unstable) LC -II Iliac wing fracture posteriorly (unstable) LC -III Windswept pelvis (contralateral SI injury) LC -III Windswept pelvis (contralateral SI injury) ANTERIOR-POSTERIOR COMPRESSION ANTERIOR-POSTERIOR COMPRESSION APC - I Partial disruption APC - I Partial disruption APC - II Posterior sacroiliac ligaments intact APC - II Posterior sacroiliac ligaments intact APC - III Posterior sacroiliac ligaments disrupted APC - III Posterior sacroiliac ligaments disrupted VERTICAL SHEAR cephlad and posterior displacement VERTICAL SHEAR cephlad and posterior displacement COMBINED MECHANISM (LC & VS most common) COMBINED MECHANISM (LC & VS most common) Young-Burgess Classification Slide 41 CLASSIFICATION Mechanism and direction of injury Slide 42 DISRUPTED PELVIC RING Posterior/SI injury is a marker for associated vascular injuries Tamponade efforts and fluid resuscitation may be rendered useless Slide 43 Resuscitation Young and Burgess classification: LC III APC II APC III VS CM Slide 44 units blood 1st 24 hours RESUSCITATION REQUIREMENTS Slide 45 Deaths : Mortality Slide 46 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, OToole RV, Turen C, Ortho June 2009 Interobserver moderate degree of agreement Intraobserver- moderate for Tile Substantial for Burgess Slide 47 LATERAL COMPRESSION LC I: Sacral compression Slide 48 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. Slide 49 LC-I Slide 50 LATERAL COMPRESSION Common anterior pattern Slide 51 LATERAL COMPRESSION LC I: Sacral compression Slide 52 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 Slide 53 LATERAL COMPRESSION LC II: Iliac wing fracture Slide 54 LC-II Slide 55 Slide 56 LC III: Windswept pelvis Slide 57 LC III Slide 58 Slide 59 Slide 60 Anteroposterior Compression APC1- stable injury, anterior ligament injury. APC2 SS and anterior SI injury, possibly ST. APC3 anterior and posterior injury, completely unstable. Slide 61 ANTEROPOSTERIOR COMPRESSION AP I: Hockey player Slide 62 AP I Note that the ligaments are stretched, and not torn Slide 63 APII: Open book pelvis ANTEROPOSTERIOR COMPRESSION Slide 64 AP II APC-2 Sacrotuberous, sacrospinous, and anterior SI joint ligaments disrupted (post SI ligaments intact) are Note: pelvic floor ligaments are violated, as well as anterior SI ligaments Slide 65 AP-II Slide 66 AP II Ligamentous pathology Slide 67 AP II These anterior SI ligaments are disrupted... But these posterior SI ligaments remain intact Slide 68 ANTEROPOSTERIOR COMPRESSION APC III: Complete iliosacral dissociation APC-3 Complete SI joint disruption (usually not vertically displaced) Slide 69 AP III Slide 70 APC-III Slide 71 AP III Slide 72 ASSOCIATED INJURIES Lateral Compression: l Abdominal visceral injury l Head injury l Few pelvic vascular injuries AP Compression: l Urologic injury l Hemorrhage/pelvic vascular injury: APCII-10%, APCIII-22% Slide 73 Vertical Shear Always unstable Ant. symphsis or vertical rami fractures- post. Injury variable Vertical displacement Slide 74 VERTICAL SHEAR Vertically unstable often due to a unilateral injury. Similar to APC3. Slide 75 VERTICAL SHEAR Slide 76 COMBINED MECHANICAL INJURY Combined vect