Procedure notes

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  Instability of C1-2 may be due to trauma, infection, tumors, or rheumatoid arthritis. In deciding the appropriate management of unstable C1-2 injuries, the patient’s age, medical status, and compliance and the fracture pattern and whether or not ligamentous injury is involved must be considered. One treatment modality that is widely accepted is closed reduction with halo vest placement. This treatment can cause patient dissatisfaction, however, and lack of compliance may lead to pin site infection and loss of alignment.

  
  
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  Over the last decade, internal fixation has become a standard treatment for managing unstable C1-2. Posterior wiring techniques as described by Brooks and Jenkins and by Gallie have been widely used but have a significant rate of nonunion and fracture displacement. Posterior transarticular screw fixation, as later described by Magerl and Seeman, has decreased failure rates but is technically more demanding and has a high risk of inadvertent vertebral artery injury. Anterior C1-2 fixation may be used as an alternative method when posterior fusion is undesirable.

Indications

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  For treatment of C1-2 instability (from trauma, infection, tumors, or rheumatoid arthritis).

  
  
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  Inability to tolerate prone position surgery because of pulmonary issues and requiring C1-2 fixation.

  
  
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  Unstable odontoid fracture, nonunion, or os odontoideum.

  
  
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  Tumor resection involving the dens.

  
  
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  Basilar impression.

  
  
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  Posterior arches of C1-2 are injured and cannot hold hardware for stability.

  
  
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  Dorsal bony anatomy of C1-2 precludes placement of posterior transarticular screws.

Contraindications

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  Short neck and barrel-shaped chest hindering operative access

  
  
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  Facial fractures or temporomandibular pathology

  
  
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  Injury to anterior bony architecture injury and cannot hold hardware for stability

Planning and positioning

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  In deciding the appropriate management of unstable C1-2 injuries, the patient’s age, medical status, and compliance and the fracture pattern and whether or not ligamentous injury is involved must be considered.

  
  
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  Preoperative computed tomography (CT) can be reviewed to evaluate adequate bony integrity of C1 lateral masses and C2 vertebral body and to select appropriate length for screws.

  
  
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  Closed reduction of C1-2 segment may be adequately achieved with halo or Gardner-Wells tong traction.

  
  
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  The patient is positioned supine on a radiolucent table with the head slightly extended. Proper positioning should be assessed with fluoroscopic guidance. The table may need to be rotated 180 degrees on its base to allow maximum room for fluoroscopic positioning.

  
  
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  The patient is intubated via awake fiberoptic technique.

  
  
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  Broad-spectrum antibiotics with gram-positive and gram-negative coverage should be given 30 minutes before the incision.

  
  
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  Spinal cord monitoring is highly recommended.

  
  
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  A biplanar fluoroscope is brought around the operating table and covered with sterile drapes at the beginning of the case. When the fluoroscope is draped, it can be pushed toward the foot of the table and brought in to visualize adequate reduction and hardware placement.

  
  

  
  

  
  

  

  
  

  
  

  Positioning of staff and equipment in the operating room. The anesthesiologist is positioned at the head of the patient; the scrub nurse and basic table are placed at the patient’s torso on the same side as the surgeon; the operating microscope comes in behind surgeon; the C-arm is draped and pushed down in between the surgeon and scrub nurse with the base located opposite from the surgeon; electrophysiology monitoring is positioned at the contralateral side of the surgeon.

  
  

Procedure