Executive Editor: Peter Trafton

Authors: Rahul Banerjee, Peter Brink, Matej Cimerman, Tim Pohlemann, Matevz Tomazevic

Pelvic ring - Sacrum

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Glossary

General considerations

Before proceeding with definitive repairs, the patient must be fully resuscitated, fully evaluated, and fit for anesthesia and surgery by a prepared team.

Treatment of type B and C sacral fractures depends upon nerve root involvement, fracture pattern, and degree of instability. (Type A3 fractures are covered under that diagnosis.)

A careful physical examination and a high quality CT scan are necessary for adequate assessment. If a neural deficit correlates anatomically with a sacral fracture, posterior decompression, anatomic reduction, and stable fixation should be seriously considered.

Sacral fractures without a neurologic deficit should be assessed regarding fracture anatomy and stability. The commonest are unilateral anterior sacral compression fractures associated with lateral compression injuries (B2.1 = LC1). Usually these are stable and predictably do well with non-operative treatment. However, their spectrum of stability includes injuries that are complete, displaced and/or comminuted, with associated anterior arch fractures or total posterior SI ligament ruptures. Without recognition and posterior fixation, these are likely to displace or fail to unite.

Unilateral totally unstable injuries (C1.3) which are undisplaced and without neurologic deficit are often good candidates for in situ iliosacral screw fixation. If displaced, anatomical reduction and stable fixation are recommended, together with anterior arch repair. Usually a posterior ORIF is required, for optimal reduction and avoidance of neurologic injury. Caution is necessary regarding soft tissue injury in the operative field. With exceptionally unstable vertical transforaminal fractures, including those with L5-S1 facet involvement, triangular fixation or other combined techniques should be considered.

Bilateral sacral fractures (C2.3, C3.3) are almost always unstable and need reduction and fixation based on each fracture pattern. They may include a horizontal component, and thus represent spinopelvic dissociation, with frequent neurologic involvement. Neural decompression, reduction, and stable fixation are indicated, once the patient’s condition permits. Typically, spinopelvic fixation is advisable.

External fixation and traction (resource-limited)
Main indication Skill Equipment
Unstable pelvic ring injury without availability of posterior pelvic fixation Basic surgical experience, no specialized skills Simple surgical and imaging resources

Indications

  • Unstable pelvic injury without availability of posterior pelvic fixation
  • Proximal displacement of the involved hemipelvis or risk thereof
  • Need to delay definitive surgery because of patient's condition

Contraindications

  • Availability of comprehensive pelvic ring fixation without excessive delay
  • Skeletal traction should not be applied if the involved hemipelvis is distally &/or anteriorly displaced. A circumferential wrap should be applied.

Advantages

  • Readily available
  • Low cost
  • Technically less demanding

Disadvantages

  • Prolonged bed rest
  • Less stable than internal fixation
  • Reduction may be harder to obtain and maintain
External fixation
Main indication Skill Equipment
Temporary splint for unstable pelvic ring Some specialized surgical experience Simple surgical and imaging resources

The choice between iliac crest pins and supra-acetabular pins is surgeon's preference.

Indications

  • Temporary splint for hemorrhage control
  • Definitive option for pubic ramus fractures after posterior repair
  • Intraoperative reduction aid

Contraindications

  • External fixation alone is inadequate for a completely unstable pelvic ring

Advantages

  • Rapid non-invasive application
  • Adjustable

Disadvantages

  • Pin track problems
  • Limited stability
ORIF sacrum
Main indication Skill Equipment
Displaced unstable (Type C) sacral fracture + nerve root injury Highly experienced and skilled surgeon Full specialized surgical and imaging resources

Indications

  • Displaced unstable sacral fractures (as part of Type C pelvic ring injury)
  • Sacral fracture with nerve root injury (by exam) or compression (by CT)
  • Closed reduction unsuccessful

Contraindications

  • Injured posterior soft tissues
  • Failure to recognize lumbosacral dissociation (which requires spinopelvic fixation)

Advantages

  • decompression of neural canal and sacral roots is possible
  • Direct reduction possible

Disadvantages

  • Technically demanding
  • Requires adequate implants
  • Anterior pelvic arch fixation necessary to protect sacral fixation
  • Soft tissue injury may cause wound slough or infection
  • Potential injury to nerve roots
Iliosacral screw for sacrum
Main indication Skill Equipment
Well aligned, unstable sacral alar fracture; neurologically intact Highly experienced and skilled surgeon Full specialized surgical and imaging resources

Indications

  • Reduced unstable sacral alar fracture, especially in Type C pelvic ring injuries, without neurologic deficit or compression
  • Complete sacral alar fractures in Type B2.2 (LC1) injuries, especially with comminution, multiple, or bilateral pubic ramus fractures
  • Selected bilateral sacral alar fractures
  • Undisplaced U-type spinopelvic fractures

Contraindications

  • Uncorrected displacement of sacral fracture (>5mm displacement)
  • Nerve root injury, needing posterior decompression
  • Adequate intraoperative imaging is not possible
  • Comminuted sacral alar fracture (relative)
  • As only fixation for spinopelvic dissociation

Advantages

  • Usually good stability (may require more than one screw)
  • Interfragmentary compression may be achieved (or prevented with fully threaded screw)
  • Open surgery not required for IS screw fixation
  • May be used with either prone or supine position

Disadvantages

  • Technically demanding
  • Good C-arm imaging required
  • Transforaminal fracture with vertical shear &/or comminution may remain unstable
  • Screws may injure nerves or vessels
  • Intraoperative imaging may not identify screw placement errors
  • Possibly extended fluoroscopy time
  • Malpositioned screws may not be identified until post-procedure CT scan
Iliosacral screw navigation
Main indication Skill Equipment
Well aligned, unstable sacral alar fracture; navigation technology available Highly experienced and skilled surgeon Full specialized surgical and imaging resources

Indications etc. are the same as for ISS fixation without navigation, but the surgical team must be expert with the available equipment, as well as in doing the procedure the procedure without computer navigation.

Triangular osteosynthesis
Main indication Skill Equipment
Vertically unstable transforaminal sacral fractures Highly experienced and skilled surgeon Full specialized surgical and imaging resources

Indications

  • Selected highly unstable transforaminal comminuted sacral alar fractures,
  • Inability to fix securely with ISS

Contraindications

  • Spinopelvic dissociation (needs bilateral construct)

Advantages

  • Mechanically stable construct to improve vertical stability
  • Can be used with supplementary interfragmentary sacral fixation
  • Avoids excessive interfragmentary compression

Disadvantages

  • Removal of the implant is required
  • Non-union of fracture
  • Tilting of L5 body from excessive spinopelvic distraction
  • Nerve root injury risk is increased
Ilioiliac plate
Main indication Skill Equipment
Displaced, unstable sacral alar fractures, especially bilateral Highly experienced and skilled surgeon Full specialized surgical and imaging resources

Indications

  • Displaced, unstable sacral alar fractures, especially bilateral
  • Selected central sacral fractures

Contraindications

  • Poor soft tissue conditions at the surgical site (e.g. contusions or Morell-LaVallée injury)
  • As isolated fixation for spinopelvic dissociation

Advantages

  • Permits open reduction and nerve root decompression
  • Fixation may be limited to sacrum, or extended to posterior ilia
  • Can be used to bridge comminuted sacral fractures
  • Sacral fragment screw fixation can be obtained when anatomy permits
  • Can be performed either as open or minimally invasive technique

Disadvantages

  • Technically demanding
  • Risk of wound slough and infection
  • Implant removal may be necessary
  • Good imaging necessary for sacral screw placement
Spinopelvic fixation
Main indication Skill Equipment
Transverse central sacral fracture, displaced or unstable; nerve root injury Highly experienced and skilled surgeon Full specialized surgical and imaging resources

Indications

  • Upper sacral fracture with transverse component, disconnecting spine from pelvis
  • Unstable central sacral fractures, especially with nerve root injury
  • Transforaminal sacral fractures, with proximal involvement of L5/S1 facet joint
  • Bilateral vertically unstable sacral alar fractures

Contraindications

  • Posterior pelvic soft tissue injury (contusion, Morel Lavallée lesion, etc.)

Advantages

  • Provides stability of spino-pelvic fixation
  • Provides access for open reduction and nerve root decompression
  • Additional interfragmentary sacral fixation is possible

Disadvantages

  • Risk of wound slough and infection
  • Prominent hardware may be painful &/or require removal
  • Technically demanding
  • Good imaging necessary
*Skill
Basic surgical experience, no specialized skills Basic surgical experience, no specialized skills
Some specialized surgical experience Some specialized surgical experience
Highly experienced and skilled surgeon Highly experienced and skilled surgeon
*Equipment
Basic equipment only Basic equipment only
Simple surgical and imaging resources Simple surgical and imaging resources
Full specialized surgical and imaging resources Full specialized surgical and imaging resources

v1.0 2015-12-10