This study presents the results of magnetic resonance imaging (MRI) follow-up studies on 14 patients with unstable fractures of T12 or L1. Internal fixation was performed with Harrington rods in eight patients and with transpedicular fixation in six patients. Sixteen intervertebral disks adjacent to the fractured vertebral body in 11 patients showed decreased signal intensity in T2-weighted images. None of the uninjured intervertebral disks showed any detectable signal decrease in T2-weighted images. Temporary fixation of several healthy motion segments of thoracolumbar spine, as is necessary with Harrington instrumentation for 11 months, on average, does not seem to result in an intervertebral disk degeneration detectable on MRI in the patients within a follow-up period of two years.