Introduction

The successful management of pelvic ring injuries requires understanding of complex pelvic anatomy, determinants of stability, mechanism of energy, and host factors. High-energy unstable pelvic ring injuries may be associated with hemodynamic instability upon presentation to the trauma bay, and the treating practitioner must be able to function as an effective member of the resuscitating team when such a clinical presentation occurs (▶Video 30.1).

I. Preoperative

1. 
   

   History

   
   
   
   
   1. 
      

      Frequently results from a high-energy mechanism of injury in young patients (motor vehicle crash, motorcycle crash, bicycle crash, pedestrian struck, or fall from height).

      
      
   2. 
      

      May result from low-energy mechanism in elderly patients (fall from standing).

      
      
   3. 
      

      Multiple injuries are common in patients with high-energy pelvic ring disruptions.

   
   
2. 
   

   Physical exam

   
   
   
   
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      Pain.

      
      
   2. 
      

      Hip, flank, perineal ecchymosis, and labial and scrotal swelling are common.

      
      
   3. 
      

      Subtle open injuries may be detected by careful examination of gluteal folds, perineum, genitalia, rectum, and flank.

      
      
      
      
      1. 
         

         Blood at meatus of urethra may be a sign of urethral or bladder injury.

         
         
      2. 
         

         Vaginal or scrotal tears can be subtle.

         
         
      3. 
         

         Fracture may be open into vagina or rectum necessitating digital exam of both.

      
      
   4. 
      

      Nerve palsy:

      
      
      
      
      1. 
         

         Lumbosacral plexus is in close proximity to the posterior pelvic ring.

         
         
      2. 
         

         Peripheral nerve exam of lower extremities may detect injuries.

   
   
3. 
   

   Anatomy

   
   
   
   
   1. 
      

      Osteology (▶ Fig. 30.1 ):

      

      
      
      
      
      1. 
         

         Osseous pelvic ring comprises two innominate bones linked anteriorly at the symphysis pubis and posteriorly at the sacroiliac (SI) joints bilaterally.

         
         
      2. 
         

         The bony connections are stabilized by ligamentous attachments—there is no inherent bony stability.

         
         
      3. 
         

         Anatomic osseous variety in the sacrum (sacral dysmorphism) as well as in the anterior pelvic ring must be appreciated and understood if successful and safe operative fixation is to be performed. Sacral dysmorphism:

         
         
         
         
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           i. Failure of segmentation in the upper sacral segment.

           
           
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           ii. Osseous variation leads to radiographic findings (▶ Fig. 30.2):

           

           
           
           
           
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             Alar regions that have a cranial and anterior slope.

             
             
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             Mamillary processes.

             
             
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             Irregular upper segment nerve root tunnels.

             
             
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             Non-recessed upper segment on outlet view.

             
             
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             Tongue-in-groove SI joints.

             
             
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             Persistence of the S1 disc.

      
      
   2. 
      

      Soft tissue:

      
      
      
      
      1. 
         

         Posterior ligaments—anterior, intra-articular, and posterior SI ligaments, as well as sacrospinous and sacrotuberous ligaments.

         
         
      2. 
         

         Anterior ligaments—symphyseal ligaments.

      
      
   3. 
      

      Neurologic:

      
      
      
      
      1. 
         

         Lumbosacral plexus (▶ Fig. 30.3 ).

         

         
         
      2. 
         

         Sacral nerve roots exit at the bottom of the corresponding vertebral body foramina. For example, S1 roots exit at the bottom of S1.

         
         
      3. 
         

         L5: runs along cranial anterior surface of bilateral sacral alae.

   
   
4. 
   

   Imaging:

   
   
   
   
   1. 
      

      Radiographs—anteropoterior (AP), inlet, and outlet (▶ Fig. 30.4 ).

      

      
      
      
      
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         Anterior-posterior:

         
         
         
         
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           i. Patient is placed supine, and beam is directed anterior to posterior.

           
           
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           ii. Tip of coccyx should be at the symphysis pubis.

           
           
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           iii. Lumbar spinous processes should be in line with pubic symphysis.

           
           
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           iv. Evaluates cranial and caudal displacement (in conjunction with outlet view).

         
         
      2. 
         

         Inlet—radiograph is taken with patient supine. Beam is directed caudally approximately 60 degrees but can be variable depending on an individual’s pelvic tilt and body habitus.

         
         
         
         
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           i. Helpful for demonstrating posterior displacement or (less commonly) anterior displacement of osseous structures.

           
           
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           ii. Demonstrates internal or external rotation.

         
         
      3. 
         

         Outlet—radiograph is taken with patient supine with variable cranial tilt, often between 20 and 40 degrees, ideally superimposing the cranial aspect of the symphysis at the level of the second sacral segment.

         
         
         
         
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           i. Reveals sacral morphology.

           
           
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           ii. Highlights cranial or (less commonly) caudal displacement of osseous structures.

      
      
   2. 
      

      CT scan:

      
      
      
      
      1. 
         

         Axial scan may demonstrate fine detail of posterior pelvic ring injuries and morphology.

         
         
      2. 
         

         Soft tissue windows may reveal visceral injury, bleeding, occult open injuries, and core muscle anatomy.

         
         
      3. 
         

         Three-dimensional reconstructions, while not generally necessary, can be useful for understating complex injury patterns.

      
      
   3. 
      

      Dynamic exam under anesthesia with fluoroscopy (EUAF):

      
      
      
      
      1. 
         

         Patient is placed supine with fluoroscope brought in for inlet and outlet views.

         
         
      2. 
         

         Examination is done with physician applying manual stress to cause deformity (▶ Fig. 30.5 ).

         

         
         
         
         
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           i. Push-pull maneuver (push on one side and pull on the contralateral leg).

           
           
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           ii. External rotation stress accomplished by frog-legging both extremities.

           
           
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           iii. Internal rotation stress done by internally rotating one leg with or without a lateral force applied to the ipsilateral greater trochanter.

         
         
      3. 
         

         Dynamic imaging may reveal occult instability that may not be evident on static pelvic radiographs (▶ Fig. 30.6 ).

         

   
   
5. 
   

   Classification of pelvic ring fractures: Young and Burgess (▶ Fig. 30.7 ).

   

   
   
   
   
   1. 
      

      Based on the force vector applied to the pelvis that leads to predictable patterns of deformity and instability.

      
      
   2. 
      

      Predictive of associated injuries, mortality, and resuscitative requirements.

      
      
   3. 
      

      Fracture types:

      
      
      
      
      1. 
         

         Lateral compression (LC):

         
         
         
         
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           i. Laterally directed force causing variable anterior (typically horizontally oriented ramus fractures) and posterior injuries.

           
           
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           ii. Likelihood of instability increases from LC-1 to LC-3.

           
           
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           iii. LC-1—laterally directed force applied to the posterior pelvis resulting in a wide spectrum of sacral injury ranging from incomplete anterior sacral buckle fractures to complete fractures of the sacrum with or without displacement.

           
           
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           iv. LC-2—laterally directed force applied to the anterior pelvis leading to rami fracture(s), internal rotation deformity, and posterior SI joint fracture dislocation (crescent fracture).

           
           
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           v. LC-3—greater force leading to internal rotation of the pelvis on the side of impact and contralateral external rotation deformity (“windswept pelvis”).

           
           
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           vi. Mortality increases from LC-1 to LC-3 usually due to factors outside the pelvis (head, neck, and chest trauma).

         
         
      2. 
         

         Anterior-posterior compression (APC):

         
         
         
         
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           i. Anteriorly directed force resulting in opening of anterior pelvic ring usually at symphysis pubis or less commonly vertically oriented rami fractures with variable degrees of posterior SI joint injury.

           
           
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           ii. Instability increases from APC-1 (stable) to APC-2 (rotationally unstable) to APC-3 (completely unstable).

           
           
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           iii. APC-1—anterior ring injury without posterior element disruption typically manifested by pubic symphysis diastasis less than 2.5 cm.

           
           
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           iv. APC-2—classically described as pubic symphysis diastasis > 2.5 cm (not absolute) and displacement of the anterior SI joint resulting in a rotationally unstable hemipelvis. The following ligaments are proposed to be injured to variable degrees leading to rotational instability: anterior SI ligament, sacrotuberous ligament, and sacrospinous ligament.

           
           
           
           
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             APC-3—pubic symphyseal displacement and SI joint dislocation described as rotationally and vertically unstable. The posterior SI ligamentous complex is completely disrupted.

           
           
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           v. Mortality increases from APC-1 to APC-3 usually due to pelvic hemorrhage.

           
           
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           vi. APC-3 has the highest resuscitative fluid requirements, blood product requirements, and risk of mortality of all pelvic ring fractures.

         
         
      3. 
         

         Vertical shear (VS):

         
         
         
         
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           i. Cranial displacement of unstable pelvic segment.

           
           
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           ii. Similar mortality and resuscitation requirements of an APC-2 fracture.

         
         
      4. 
         

         Combined mechanical injury (CMI): Fracture pattern that does not fit in to the other categories.

         
         
         
         
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           i. No specific mechanism can be applied to the injury pattern.

           
           
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           ii. AO/OTA/Pennal–Tile classification (▶ Fig. 30.8 ).

           

           
           
           
           
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             Alphanumeric system

             
             
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             Intended to predict stability.

             
             
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             Ideal for research cataloging—not generally used in daily communication.