Anatomy, Radiographic Evaluation, Classification and Complication of Pelvic Ring InjuriesIB Aditya Wirakarna

Marker for severe injuryOverall mortality 6-10%Life threateningPelvic Ring Disruption

Magnitude of ForcesACL injury 500-1000NLC-I pelvic fracture 6000-9000N

Bone AnatomyTwo 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 mmSI joint 2-4 mm

Ligamentous AnatomyLigaments - posterior ligaments are stronger than anterior ligaments:Posterior SIAnterior SI Interosseous ligamentsPubic symphysis SacrotuberousSacrospinous

ANATOMYLigamentousASISTSSPSIST

Posterior LigamentsAnt. SI Joint resist external rotationPost. SI and Interosseous posterior stability by tension band (strongest in body)Iliolumbar ligaments augments posterior complexSacrotuberous (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 rotationIntact cadaver resist 5,837 N (1,212 lbs)

ANATOMYRelationships

Vascular AnatomyInternal 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 AnatomyBlunt vs. impaled by bony spikeBladder/urethraRectum Vagina

Pelvic StabilityStrength of ring: 40% anterior and 60% posterior.Vsphere = 4/3r.

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

IDENTIFY THE HIGH RISK PELVIC DISRUPTIONBy Physical ExamBy Radiography

Physical ExamPhysical Exam-poor sensitivity (8%) for mechanically unstable pelvis fractures in blunt trauma patients

Shlamovitz GZ, Mower WR, Morgan MT-Journal of Trauma Mar 09

RadiographsAnteroposterior (AP)Inlet (40 caudad)Outlet (40 cephalad)CT scanJudet (acetabular fractures)

AP VIEWIf evidence of pelvic ring fracture...

INLET VIEW

Inlet (Caudad) ViewHorizontal Plane RotationPosterior DisplacementSacral ala

OUTLET VIEW

Outlet (Cephalad) ViewSacrumCephalad DisplacementSacral Foramina

CT ScanBetter defines posterior injuryAmount of displacement versus impactionRotation of fragmentsAmount of comminutionAssess neural foramina

CT SCAN

3D CT

Radiographic Signs of InstabilitySacroiliac displacement of 5 mm in any planePosterior fracture gap (rather than impaction)Avulsion of fifth lumbar transverse process, lateral border of sacrum (sacrotuberous ligament), or ischial spine (sacrospinous ligament)

Translational DeformitiesX axis Diastasis or impactionY axis Caudad or cephalad displacementZ axis Anterior or posterior displacement

Rotational DeformitiesX axis Flexion or extensionY axis Internal rotation or external rotationZ axis Abduction or adduction

ClassificationAids in predicting hemodynamic instabilityAids in predicting visceral and g.u. injuriesAids in predicting pelvic instabilityAids in understanding mechanism of injury, force vector of injury, and surgical tactic for reduction

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

Anatomical Classification(Letournel)Where The Pelvis Breaks

Anterior PosteriorRami fracturesSymphyseal disruption

Iliac wing fractureIliac wing/sacroiliac (SI) joint (crescent fracture)SI jointSacrum/SI jointSacrum fracture

Pennal, 1961 Bucholz, 1981 Tile, 1988 Magnitude and direction of forcesLateral posterior compression (LC)Anterior posterior compression (APC)Vertical shear (VS)

Added stability to the classification

Tile ClassificationType A: Stable fracture.Type B: Rotationally unstable, but vertically stable.Type C: Rotationally and vertically unstable.

OTA/AO Pelvic Injury Classification61A Lesion sparing (or with no displacement of ) posterior archB Incomplete disruption at posterior arch; partially stableC Complete disruption of posterior arch; unstable

A Fractures Ring IntactA-1 Fracture of innominate bone; avulsionA-2 Fracture of innominate bone; direct blowA-3 Transverse fracture of sacrum and coccyx

B-Ring Injury Partially stableB-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 PelvisC-1 Unilateral, complete disruption of posterior archC-2 Bilateral, ipsilateral complete, contralateral incompleteC 3 Bilateral, complete disruption

Young-Burgess Radiology 1986Based on mechanism of injuryPredictive of associated local & distant injuryUseful 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 2007more reliable for LC than AP mechanisms

MECHANISM OF INJURY

Lateral compression (implosion)AP compression (external rotation)Vertical shearCombined injury

LATERAL COMPRESSION fracture of anterior ring plus:LC -I Compression fracture of anterior sacrumLC -II Iliac wing fracture posteriorly (unstable)LC -III Windswept pelvis (contralateral SI injury)ANTERIOR-POSTERIOR COMPRESSIONAPC - I Partial disruptionAPC - II Posterior sacroiliac ligaments intactAPC - III Posterior sacroiliac ligaments disruptedVERTICAL SHEAR cephlad and posterior displacementCOMBINED MECHANISM (LC & VS most common)Young-Burgess Classification

CLASSIFICATIONMechanism and direction of injury

DISRUPTED PELVIC RINGPosterior/SI injury is a marker for associated vascular injuriesTamponade efforts and fluid resuscitation may be rendered useless

ResuscitationYoung and Burgess classification:LC IIIAPC IIAPC IIIVSCM

units blood 1st 24 hoursRESUSCITATION REQUIREMENTS

Deaths:Mortality

Interobserver Reliability of the Young/Burgess and Tile classificationsKoo H, Leveridge M, McKee,MD, Schemitsch EH, J Ortho Trauma Jul 2008Young/Burgess Kappa .72-better for the training surgeonCT-improved assessment of stability

Furey AJ, OToole RV, Turen C, Ortho June 2009Interobserver moderate degree of agreementIntraobserver- moderate for TileSubstantial for Burgess

LATERAL COMPRESSIONLC I: Sacral compression

Lateral CompressionMost 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 COMPRESSIONCommon anterior pattern

LATERAL COMPRESSIONLC I: Sacral compression

What Constitutes a LCILefaivre KA, Padalecki JR, Starr AJ- J Ortho Trauma Jan 2009

LC I-Spectrum of injuries

Complete sacral disruptionsDenis classificationPredicted by severity of anterior pelvic ring disruptionAbdominal AISRami fracture locationISS

LATERAL COMPRESSIONLC II: Iliac wing fracture

LC-II

LC-II

LC III: Windswept pelvis

LC III

LC III

LC III

Anteroposterior CompressionAPC1- stable injury, anterior ligament injury.APC2 SS and anterior SI injury, possibly ST.APC3 anterior and posterior injury, completely unstable.

ANTEROPOSTERIOR COMPRESSIONAP I: Hockey player

AP INote that the ligaments are stretched, and not torn

APII: Open book pelvisANTEROPOSTERIOR COMPRESSION

AP IIAPC-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 IILigamentous pathology

AP IIThese anterior SI ligaments are disrupted...But these posterior SI ligaments remain intact

ANTEROPOSTERIOR COMPRESSIONAPC III: Complete iliosacral dissociationAPC-3 Complete SI joint disruption (usually not vertically displaced)

AP III

APC-III

AP III

ASSOCIATED INJURIESLateral Compression:Abdominal visceral injuryHead injuryFew pelvic vascular injuriesAP Compression:Urologic injuryHemorrhage/pelvic vascular injury:APCII-10%, APCIII-22%

Vertical ShearAlways unstableAnt. symphsis or vertical rami fractures-post. Injury variableVertical displacement

VERTICAL SHEARVertically unstable often due to a unilateral injury.Similar to APC3.

VERTICAL SHEAR

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

COMBINED MECHANICAL INJURY

CLASSIFY INJURY (Young-Burgess)LC-I, AP-IAP-IIAP-III, VSConservativeTreatmentAnteriorStabilizationAnterior and Posterior Stabilization

Surgeon variability in the treatment of pelvic ring injuriesFurey AJ, OToole RV, Nascone JW, Sciadini MF- Ortho Oct 2010Young and Burgess, and Tile ClassificationsKappa Value-Intraobserver- 0.56 moderate agreementInterobserver- 0.47 moderate agreement

Consistent treatment for certain patterns

ASSOCIATED INJURIESAbdominal visceral injuryHead injuryFew pelvic vascular injuriesUrologic injuryInjuries to the RectumHemorrhage/pelvic vascular injury:APCII-10%, APCIII-22%

Injuries to the RectumMost commonly, injuries to the rectum occur with penetrating rather than blunt pelvic traumaTraditionally, rectal trauma had been managed with the principle of the four Ds: divert, drain, direct repair, and distal washoutChallenging these current principles is difficult as extraperitoneal rectal injuries are rare, limiting a large-scale study, and the clinical consequences of pelvic sepsis without proximal diversion of the fecal stream can be a disastrous scenario in an often already multiply injured patientAlthough less common with blunt bony pelvic injury, 25 % of patients with an open pelvic fracture have an associated rectal laceration (Jones-Powell class III)In this study, the highest mortality and highest ISS scores were for patients with a combination of open pelvic fracture and rectal laceration underscoring the synergistic effect of combined pelvic injuries on mortality

Injuries to the RectumTypically, any penetrating injury to the pelvis or significant pelvic fracture should raise concern for a rectal injuryAs mentioned previously, rectal trauma requiring surgical intervention is rare with a blunt trauma.In contrast, when a penetrating injury traverses the pelvis, the rectum must be evaluated

Injuries to the RectumWe recommend direct visualization of the rectum with either rigid proctoscopy or flexible sigmoidoscopyDuring both procedures, the rectal mucosa is visualized circumferentially and assessed for injuryIf injury is present, repair will then depend on the degree of injury (hematoma v. laceration), anatomic location (intra- or extraperitoneal), and clinical scenario (hemodynamic status)Noninvasive imaging with CTof the rectum with rectal contrast should be used with caution as immediate imaging may not accurately assess highenergy wounds to the rectum that are only a partial injury to the wall that subsequently convert into a full thickness wound

Injuries to the RectumManagementThe extraperitoneal rectum is not easily mobilized, and mobilization, resection, and anastomosis are difficult in the elective setting and even more so in traumaTherefore, diversion of the fecal stream with a proximal colostomy with or without presacral drainage and primary repair is the current standard of care.Presacral drainage had previously been considered to be the standard of care based on management with the four Ds from the Vietnam WarSeveral retrospective studies in civilian trauma have shown no increase in pelvic sepsis or infection with the omission of presacral drainage when diverting colostomy is performed

Injuries to the RectumManagementTherefore, in civilian-penetrating pelvic injuries with a rectal wound and without massive tissue destruction, presacral drainage is unnecessary.Rectal injuries in the proximal two thirds of the rectum could be managed with primary repair or resection and anastomosis with proximal diversion at the surgeons discretion.Those wounds in the distal one third of the rectum could undergo primary repair if accessible transanally, with proximal diversion utilized if the injury was not easily accessible, with presacral drainage

Direct repair of the injury is not necessaryA retrospective study of 30 consecutive patients with penetrating extraperitoneal rectal injuries who were all treated with diverting colostomy with or without direct repair and presacral drainage showed no infectious or survival benefit for direct repair or presacral drainage

The management of combined bladder and rectal injuries may require more than just proximal diversion, however. High rates (24 %) of rectovesical and rectourethral fistula are associated with combined GU and rectal injuries.Therefore, in these instances, debridement of necrotic rectum with primary repair, proximal diversion, and the placement of an omental pedicle flap between the rectum and GU injury may reduce fistula formation especially in cases of combined posterior bladder and anterior rectal injuries.

Two to 3 months following the injury, the rectum and distal colon can be evaluated for healing and patency with a barium enema and, if adequate, the colostomy may be reversed with high rates of success

In summary, rectal trauma occurs most commonly with penetrating injuries and is quite often associated with injuries of the bladder, distal urinary system, and small bowel. Any suspicion for rectal trauma should prompt visualization of the rectum with various endoscopic equipment.Currently, injuries to the rectum should be managed with proximal diversion with additional consideration for tissue debridement and omental flap placement when there is concomitant GU injury.

Thank You