L1 burst flexion distraction with disc extrusion

Burst fracture of L1 with retropulsed fragments and reduction of the spinal canal area by approximately 25%. Fracture extends through the left L1 lamina and there and there is subluxation of the left T12-L1 facet joint and a fracture through the left L1 transverse process. L1 injury results in a thoraco lumbar kyphosis. Left L2 level transverse process is fractured.

No thoracic spine fracture.

Conclusion:

Burst fracture of L1 with severe narrowing of the spinal canal and a kyphosis. Adjacent retroperitoneal fluid without overt CT evidence of duodenal injury.

Burst fracture of L1 with retropulsion of fragments causing severe narrowing of spinal canal is noted. Retropulsed fragments indent the conus medullaris, causing compression predominantly on the left within the lateral recess, compressing the conus which has high T2 signal (predominantly left sided) without cord hematoma. There is bowing of the posterior longitudinal ligament at L1 which however appears intact. Below this level an anterior epidural hematoma is seen, not significantly narrowing the theca. Posteriorly there is a complete tear of the ligamentum flava, interspinous and supraspinous ligaments at T12/L1, with widening of the interspinous space.

No significant stenosis of the neural exit foramina on either side at T12-L1 and L1-L2.

A right sided L4/5 disc extrusion is present, filling the right subarticular recess and possibly somewhat compressing both the right L5 and right S1 nerve roots.

Small central disc protrusion at L5/S1.

Conclusion:

1. Three column injury at T12/L1
   • L1 burst fracture with retropulsion causing severe spinal canal narrowing and compression of the conus medullaris, predominantly on the left.
   • Complete ligamentous disruption posteriorly.
2. L4/5 disc extrusion.