Degeneration of cervical intervertebral disks in fighter pilots frequently exposed to high +Gz forces

Abstract

This study investigated the occurrence and the degree of cervical disk degeneration among senior fighter pilots frequently exposed to high +Gz forces, compared with nonexposed controls matched for age and sex. A resistive magnetic resonance (MR) scanner operating at 0.1 T was used to image the cervical intervertebral disks. Sagittal MR images were obtained and disk degeneration was graded 0-6. Both the occurrence and the median degree of disk degeneration were greater among the pilots than among the controls. The greatest difference in the occurrence of disk degeneration (grades 1-6), which also reached statistical significance, was detected for the C3-4 disk: 88% among the fighter pilots and 64% among the controls, respectively. With respect to the moderate degenerative changes (grades 3 and 4) in the C3-4 disk, the difference in the occurrence (88% vs. 36%) was again statistically significant. There was no difference between the other disks. The median disk degeneration between the groups differed (2.0 vs. 1.0), the difference being the most remarkable (3.0 vs. 1.0) for the C3-4 disk. The differences in the median disk degeneration were also statistically significant. These findings suggest that frequent exposure to high +Gz forces may cause premature disk degeneration.