[Spiroid fractures of the thoracic and lumbar spine].

The review of our observations of fractures of the thoracic and lumbar spine (588 files could be used from 1969 to 1989) allowed us to demonstrate fractures not included in the usual classification. In our opinion, the fracture line is spiral. The mechanism therefore includes a very likely axial rotation. The fracture line may be confined to the vertebral body (this is the type called S1) or extends to the posterior arch as well (S2 type). The fractures often cause nerve root lesions. However, no complications involving the cord were noted in our series, even in the few cases showing considerable displacement. Note the tendency to axial telescoping of the focus, which requires specific modalities of treatment.