+Gz associated stenosis of the cervical spinal canal in fighter pilots.

Previous magnetic resonance imaging (MRI) studies have shown that repeated exposure to +Gz forces can cause premature degenerative changes of the cervical spine (i.e. a work-related disease). This paper reports on two clinical cases of +Gz-associated degenerative cervical spinal stenosis caused by dorsal osteophytes in fighter pilots. Conventional x-rays and MRI were used to demonstrate narrowing of the cervical spinal canal. The first case was complicated by a C6-7 intervertebral disk prolapse and a congenitally narrow spinal canal. The second case involved progressive degenerative spinal stenosis in the C5-6 disk space which required surgery. The findings in this case were confirmed by surgery which showed posterior osteophytes and thickened ligaments compressing the cervical medulla. These two cases suggest that +Gz forces can cause degenerative spinal stenosis of the cervical spine. Flight safety may be jeopardized if symptoms and signs of medullar compression occur during high +Gz stress. It is recommended that student fighter pilots undergo conventional x-rays and MRI studies in order to screen out and reject candidates with a congenitally narrow spinal canal. These examination methods might be useful in fighter pilots' periodic medical check-ups in order to reveal acquired degenerative spinal stenosis.