Spontaneously occurring fractures of the spine in skeletally immature animals.

Abstract

Twelve spontaneously occurring fractures of the spin in nine skeletally immature animals were investigated. These fractures were analyzed radiographically, morphologically, and histologically. The most commonly injured regions were the cervical and lumbar regions. Multiple-level fractures were noted in three specimens. Morphologic and histologic examination invariably detected fractures in cases of spinal cord injury without radiographic abnormality. The end-plate physes and synchondroses were found to be the "weak links" for propagation of fractures. Radiographically benign-appearing ring apophyseal fractures were found histologically to propagate from the end-plate physis through the vertebral body via the contiguous neurocentral synchondroses. The observed morphologic and histologic fracture patterns should provide a better understanding of the probable comparable pathoanatomy of spine and spinal cord injuries in children.