Executive Editor: Peter Trafton

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

Pelvic ring - SI-joint

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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.

Sacroiliac joint injuries are purely ligamentous or involve an articular fracture. The purely ligamentous injuries in which the posterior SI ligaments remain intact (type B) can theoretically be treated with anterior arch repair alone. If the SI joint is totally unstable, it will need internal fixation. The type of fixation will depend primarily upon the injury pattern, but iliosacral screws are generally preferred if appropriate.

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
Anterior ORIF SI fracture
Main indication Skill Equipment
Anterior open reduction of SI and fracture fixation Highly experienced and skilled surgeon Simple surgical and imaging resources

Indications

  • For anterior reduction of SI dislocation or subluxation and ORIF of (large) crescent fracture
  • Anterior SI joint margins are non-comminuted and better suited for ORIF than the patient’s posterior SI margins
  • Inability to use iliosacral screw fixation (anterior iliac fracture line; technical problems)
  • Unsuccessful closed reduction of SI joint

Contraindications

  • Anterior SI joint comminution (sacrum or ilium)
  • Anterior access inadequate for reduction or fixation

Advantages

  • Direct visualization and reduction of the SI joint and fracture
  • Operative fluoroscopy is not essential
  • Permits concurrent anterior pelvic arch repair
  • Can combine with iliosacral screw, if fracture line permits and joint contact area sufficient
  • Fixation of small crescent fracture is optional; SI joint fixation is essential

Disadvantages

  • Potential iatrogenic damage to the L5 nerve root
Posterior ORIF SI fracture
Main indication Skill Equipment
Posterior open reduction of SI and fracture fixation Highly experienced and skilled surgeon Simple surgical and imaging resources

Indications

  • Posterior reduction of SI dislocation or subluxation and ORIF of crescent fracture
  • Unsuccessful closed reduction
  • Posterior SI joint margins non-comminuted and better suited for reduction than the patient’s anterior SI margins

Contraindications

  • Compromised posterior pelvis soft tissue
  • Stable fixation unobtainable through a posterior approach

Advantages

  • Ability to expose, reduce, and fix both crescent fracture and SI joint
  • Unless comminuted or too small, fixation of fracture may stabilize SI joint
  • Additional SI joint stabilization with iliosacral screw(s) is often possible

Disadvantages

  • Must be able to restore stability of SI joint by ORIF of crescent + joint fixation
  • If the crescent fragment is small or comminuted, stable fixation is difficult
  • Risk of wound slough and infection
  • Prone position limits access to anterior pelvic arch
Iliosacral screw for sacrum
Main indication Skill Equipment
Unstable SI joint, satisfactorily reduced Highly experienced and skilled surgeon Full specialized surgical and imaging resources

Indications

  • Unstable SI joint injury, satisfactorily reduced
  • SI fracture dislocation / subluxation with insignificant fragmentation

Contraindications

  • Unreduced SI joint
  • Fractures at iliac entry site for ISS
  • Obesity or other barrier to adequate intraoperative imaging

Advantages

  • Well positioned screws provide adequate stability
  • Additional screws may be used
  • Can be combined with anterior or posterior open reduction and additional fixation

Disadvantages

  • Variable sacral anatomy must be recognized for safe screw placement
  • Nerves, blood vessels, etc. may be injured by screws.
  • High quality X-ray imaging is essential; exact location of screws may be hard to determine
Iliosacral screw navigation
Main indication Skill Equipment
Unstable SI joint, satisfactorily reduced; same as for standard C-arm technique Highly experienced and skilled surgeon Full specialized surgical and imaging resources

Indications

  • Unstable SI joint injury, satisfactorily reduced
  • SI fracture dislocation / subluxation with insignificant fragmentation
  • Available equipment and skill for use of navigation technology

Contraindications

  • Unreduced SI joint
  • Fracture at the iliac entry site for ISS
  • Obesity or other barrier to adequate intraoperative imaging

Advantages

  • Decreased X-ray exposure
  • Potential for increased accuracy of screw placement

Disadvantages

  • Learning curve and technical issues with navigation
  • Variable sacral anatomy must be recognized for safe screw placement
  • Nerves, blood vessels, etc. may be injured by screws.
  • High quality X-ray imaging is still essential
Anterior ORIF SI Joint
Main indication Skill Equipment
Inability to gain closed reduction of SI joint Highly experienced and skilled surgeon Simple surgical and imaging resources

Indications

  • Unsuccessful closed reduction of SI joint
  • Alternative to iliosacral screw fixation
  • For anterior reduction and fixation of SI dislocation or subluxation
  • Anterior SI joint margins non-comminuted and better for ORIF than posteriorly

Contraindications

  • Anterior approach compromised by soft tissue injury or other surgery
  • Ipsilateral sacral fracture

Advantages

  • Direct visualization and reduction of the SI joint
  • Operative fluoroscopy is not essential
  • May be combined with exposure for ipsilateral anterior pelvic fixation
  • Iliosacral screw remains an option for fixation, if available

Disadvantages

  • Potential iatrogenic damage to the L5 nerve root
  • Relatively extensive exposure
*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