Association of vertebral end plate fracture with pediatric lumbar intervertebral disk herniation: value of CT and MR imaging.

A retrospective review of the radiologic findings in 31 patients less than 21 years old who underwent laminotomy for lumbar disk herniation revealed six cases of associated avulsion fracture of the vertebral end plate, a prevalence of 19%. All fractures were found in the 14-17-year-old subgroup (six of 19), a prevalence of 32%. In four patients, plain radiographs did not reveal the fracture. Computed tomographic (CT) findings were diagnostic in all six cases. Magnetic resonance (MR) images, obtained in three patients, demonstrated the avulsed cortical fragment and what are assumed to be the attached Sharpey fibers. On sagittal MR images, these structures had a configuration with the appearance of a "Y" or "7". Four of these six patients underwent bilateral laminotomies. The need for more extensive surgical resection may not be apparent at plain radiography or myelography but can be predicted with CT and MR imaging.