Odentoid fracture C2 fracture

Definition

Traumatic bony disruption of odentoid fracture

Best diagnotiC clue

Lateral radiograph: anterior or posterior displacement of C1 arch vs. C2, + swelling of per vertebral soft tissue

Radiologic findings

- Lucent linear defect through base of dense, with posterior displacement of dense arch of C1 to C2 body/ arch

- opened mouth : transverse or oblique defect through dense

CT finding

- soft tissue swelling anterior to C2 in acute case

Imaging ที่แนะนำ

Opened mouth

DDX

- congenital nonunion of odentoid tip( Os odentoideum)

- metastatic or other pathologic of C2 fracture

Pathology

3 ossification centers from C2

Os odentoideum : unfuses ossification center atop C2

Classification

Type I: avulsion of tip, stable type, treat as simple immobilization

Type II: transverse fracture base of dense, M/C type, most likely to non union

Type III: fracture extending into body of C2

Prognosis

Type I: หายได้

TYpe II: ต้อง surgery เนื่อง blood supply น้อยโอกาสที่จะเกิด healing process น้อย