Degenerative cervical spine changes among early career fighter pilots : a 5-year follow-up

Abstract

Introduction Degenerative changes of the cervical spine often cause disability and flight duty limitations among Finnish Air Force (FINAF) fighter pilots. We aimed to study the effect of +Gz exposure on degenerative changes in the cervical spine by comparing cervical MRIs of FINAF fighter pilots and controls. Methods At baseline, the volunteer study population consisted of 56 20-year-old FINAF male fighter pilots (exposure group) and 56 21-year-old Army and Navy cadets (control group). Both groups underwent MRI of the cervical spine at the baseline and after 5 years. Degenerative changes evaluated using MRI included intervertebral disc (IVD) degeneration (Pfirrmann classification), disc herniations, uncovertebral arthrosis, Schmorl’s nodes, Modic changes, spinal canal stenosis, kyphosis and scoliosis. Results The degree of IVD degeneration in the whole cervical spine increased significantly in both populations with no between-group differences. The prevalence of disc herniations also tended to increase in both populations with no difference in the incidence over the follow-up. However, pilots proved to have more disc herniations at the baseline and at the follow-up. There were virtually no between-group differences in other assessed degenerative changes. Discussion We found that IVD degeneration and the prevalence of disc herniations increased at a similar rate for fighter pilots and non-flying military students when all cervical levels were summed up. The lack of difference may be explained by the relatively low cumulative +Gz exposure during the first 5 years of a pilots’ career.