Traynelis classification of atlanto-occipital dislocations

The Traynelis classification of atlanto-occipital dislocations describes injuries of the atlanto-occipital joint according to the displacement of the occipital condyles relative to the atlas:

  • type I: anterior displacement
  • type II: distraction (inferior displacement)
  • type III: posterior displacement

A limitation of this classification system is that rotatory or coronal malalignment is not taken into consideration.


Type I and III injuries are treated with longitudinal traction to reduce the dislocation followed by surgical fixation. Non operative management includes collar or halo immobilization is used for certain patients but has a high rate of failure. Persistent traction is contraindicated due to the increased rate of neurological complications.


Article information

rID: 86945
Synonyms or Alternate Spellings:

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Cases and figures

  • Figure 1: normal alignment
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  • Figure 2a: type 1
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  • Figure 2b: type 2
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  • Figure 2c: type 3
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  • Case 1: type 1
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  • Case 2: type 2
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