C1-C2 best seen in:
Ans. D. Odontoid viewJefferson's Fracture1. It is most common type of atlas fracture. It is cause by axial compression force (with or without extension force), resulting from a fall on the head from a height or mass falling on head. This mechanism of injury results in a burst fracture of ring of atlas (Cl) vertebrae, that occurs secondary to the occipital condyles being driven into the interior portions of the ring of atlas and driving the lateral masses outwards.2. Lateral displacement of Cl lateral mass lateral the outer cortex of the C2 lateral mass raises concerns for the structural integrity of the transverse Atlantal ligament (TAL). The stability of atlas depends on TAL.3. Due to outward movement of lateral masses, there is no encroachment on the neural canal and, usually, no neurological damage.4. Classical Jefferson's fracture (as described by Jefferson in 1920) was four-part fracture of ring of atlas (2 part of anterior ring & 2 part of posterior ring). However more common are two part or three part fractures.5. It is typically diagnosed on plain radiographsa. Open mouth (odontoid) view may show asymmetry of the lateral masses of Cl on C2 with overhang.b. A bilateral overhang >6.9mm suggests disruption of transverse ligament and potential late instability.c. On lateral radiograph presumptive evidence of transverse ligament disruption is >4mm atlanto-dents interval.6. Coronal CT reformation provides the best method of evaluating important atlas fracture characteristics.
Lat. view
Oblique view
AP view
Odontoid view
Skeletal System