[Tear drop fractures. Contribution to the study of the mechanism of osteo-disco-ligamentous lesions].

Since the original description by Schneider (1956), the tear drop fracture is designated as a flexion fracture. The C.A.T. investigation proves the coexistence of two lines of fractures: a frontal fracture (by mechanism of flexion), a sagittal fracture (by compression). The sagittal fracture affects the body and the posterior arch in 48% of Lee's cases (1982) as Jefferson's fracture. The tear drop fracture is a fracture by mechanism of flexion-compression with sagittal sprain of the inter vertebral cervical disk. --In our experiences C5 is the level of the most frequent lesion. --4 types of tear drop fractures are described: an occult form (C.A.T. diagnosis), tear drop without displacement, tear drop with moderate displacement, tear drop with posterior dislocation and kyphosis greater than 20 degrees. --The spinal cord damage corresponds to displacement of the two half vertebral bodies and posterior dislocation. --In case with posterior dislocation and kyphosis greater than 20 degrees complete tetraplegia or anterior spinal cord injury are often presents. --In case with asymmetrical posterior displacement of an half vertebral body the syndrom of Brown Sequard is constant. --The tear drop fracture is unstable and cervical spine fusion necessary.