Cervical Spine Disease and Surgical Intervention in the US Air Force Fighter Aviator Population 2001-2006: An Assessment of Relative Risk

by Ballard, Timothy D.

Abstract (Summary)
The purpose of this study was to analyze the historical occurrence of documented cervical spine disease (CSD) and its surgical intervention among United States Air Force (USAF) ‘fighter aviators’. Fighter aviators are routinely exposed to supraphysiologic G-forces in the vertical plane (Gz) that can trigger cervical spine disease. Previous survey-based studies have shown a high incidence of neck pain or injury reported by fighter pilots. However, no cohort studies have evaluated the clinical occurrence of CSD in this population. In this study, the clinical occurrence of CSD and its surgical intervention were evaluated among three primary USAF officer populations: fighter aviators, non-fighter aviators, and non-flying officers. Furthermore, due to the unique seat position and additional neck flexion required to fly the F-16, CSD rates among F-16 pilots were compared to ‘Non F-16 fighter aviators.’ The USAF Clinical Informatics Branch (CIB) provided de-identified data sets containing all documented CSD and surgical interventions in these populations from 2001-2006. Poisson regression analysis was conducted on all documented CSD and surgical interventions among USAF officers (2001 to 2006) and was used to assess population heterogeneity and calculate risk ratios. Fighter aviators present to clinics for CSD at a significantly lower rate (RR: 0.90, CI: 0.85-0.95, p<0.0001), yet their overall rate of having a surgical intervention in their career is significantly higher (RR: 1.46, CI 1.07-1.99, p=0.016) than non-fighter aviators. Once diagnosed with CSD, fighter aviator surgical intervention rates are even higher compared to other officer populations (RR: 1.62, CI: 1.19-2.21, p=0.002 compared to non-fighters). Interestingly, F-16 pilots have the lowest CSD rate among all officer populations (RR: 0.73, CI: 0.67-0.80, p < 0.0001) compared to non F-16 fighter aviators). While they have a lower overall surgical rate compared to Non F-16 aviators, once diagnosed with CSD, they have the highest rate of surgical intervention of all populations (RR: 1.47, CI: 0.90-2.39, p= 0.12 compared to non F-16 aviators). In conclusion, supraphysiologic Gz exposure may not be associated with increased rates of CSD, but it may be associated with increased rates of cervical surgeries among USAF fighter aviators. The seat angle of the F-16 may provide a protective factor in reducing CSD diagnoses and overall surgical rates. However, once diagnosed with CSD, the increased neck flexion (due to a unique seat angle) required to fly the F-16 may have a direct contribution to the highest surgical rate among the study populations.
Bibliographical Information:


School:University of Cincinnati

School Location:USA - Ohio

Source Type:Master's Thesis

Keywords:usaf fighter aviator cervical spine disease f 16 pilot


Date of Publication:01/01/2008

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